WEBVTT Kind: captions Language: en 00:00:00.320 --> 00:00:01.620 [laughter] 00:00:01.620 --> 00:00:03.460 Well, good morning, everyone. 00:00:03.460 --> 00:00:05.850 Thanks for coming to Ken’s talk. 00:00:05.850 --> 00:00:08.720 Before we get started, next week, Scott Bennett from the GMEG group 00:00:08.720 --> 00:00:12.820 will be here talking about some of his work on characterizing active faults 00:00:12.820 --> 00:00:17.170 in the Pacific Northwest and the implication to seismic hazard analysis. 00:00:17.170 --> 00:00:21.880 So despite Ken’s best wishes, I am going to at least read out the bio he sent us. 00:00:21.880 --> 00:00:23.500 Because he has accomplished quite a bit, 00:00:23.500 --> 00:00:25.880 and many of you in the room probably know who he is. 00:00:25.880 --> 00:00:28.620 Hold on. [laughs] 00:00:28.620 --> 00:00:32.400 So Dr. Kenneth Stokoe II has been working in the areas of – 00:00:32.400 --> 00:00:35.520 or, the fields of seismic measurements, dynamic laboratory measurements, 00:00:35.520 --> 00:00:39.040 and dynamic soil structure interaction for more than 40 years. 00:00:40.060 --> 00:00:42.700 He has been instrumental in developing several small-strain 00:00:42.710 --> 00:00:45.210 field methods for in-situ shear wave velocity measurements. 00:00:45.210 --> 00:00:47.820 He has also developed two types of resonant column systems that are 00:00:47.820 --> 00:00:51.640 used to evaluate dynamic soil and rock properties in the laboratory. 00:00:51.640 --> 00:00:55.170 Most recently, he led the development of large-scale mobile field equipment 00:00:55.170 --> 00:00:59.470 for dynamic loading and geotechnical systems, foundations and structures, 00:00:59.470 --> 00:01:03.190 and actively funded – an activity funded by the National Science Foundation. 00:01:03.190 --> 00:01:07.250 Dr. Stokoe has received several honors and awards, including the election to the 00:01:07.250 --> 00:01:11.390 National Academy of Engineering, the H. Mooney Award from the 00:01:11.390 --> 00:01:15.400 Society of Exploration Geophysicists, and the C.A. – 00:01:15.400 --> 00:01:17.200 oh, I should have read this before. [laughs] 00:01:17.200 --> 00:01:20.200 - Hogentogler Award. - All right. From ASTM. 00:01:20.200 --> 00:01:23.850 And the H. Bolton Seed Medal and the Karl Terzaghi Distinguished 00:01:23.850 --> 00:01:28.000 Lecturer from the ASCE. Ken? - And you know what that means. 00:01:28.000 --> 00:01:30.960 Believe it or not, I have friends. [laughter] 00:01:30.960 --> 00:01:33.160 Doesn’t necessarily mean anything … 00:01:33.160 --> 00:01:57.860 [Silence] 00:01:57.860 --> 00:02:00.850 … according to my wife. 00:02:02.020 --> 00:02:06.340 No, the first time I was on a leave – so I can’t call it a sabbatical – 00:02:06.350 --> 00:02:11.560 was at USGS – here. And it was with Les Youd, 00:02:11.560 --> 00:02:16.769 Albert Chan, Holzer – who was our – where – is our driller out here? 00:02:16.769 --> 00:02:17.769 - Right here. 00:02:17.769 --> 00:02:20.359 - Oh, my gosh. I didn’t – and you were – you were … 00:02:20.359 --> 00:02:24.709 - [inaudible] Chandler is not here anymore. - Ahhh. And they were laughing at me 00:02:24.709 --> 00:02:29.450 because I won – oh, I forget the name of the award, but it sounded like 00:02:29.450 --> 00:02:33.290 it was a Humorous Award. And so I was always trying to tell jokes 00:02:33.290 --> 00:02:37.260 in the field, and so he thought, from ASCE, I was the Humorous Award. 00:02:37.260 --> 00:02:40.480 I forget the name of the award now. I’m sorry. 00:02:40.480 --> 00:02:48.600 But, no, it’s – I have always enjoyed USGS and have had some grants 00:02:48.609 --> 00:02:52.099 with them, have enjoyed being out here, and have very nice friends. 00:02:52.099 --> 00:02:55.040 And I thank you very much for the opportunity. Oops. 00:02:55.040 --> 00:02:58.689 Alan, I thank you very much for the opportunity – even if he did 00:02:58.689 --> 00:03:02.109 make a bad choice [laughter] – to come out here and talk to you. Okay. 00:03:02.109 --> 00:03:06.249 If we can, I’d like to talk about surface waves. 00:03:06.249 --> 00:03:09.860 Just a brief introduction, but I will mention body and surface waves. 00:03:09.860 --> 00:03:13.409 I really won’t mention the laboratory very much, but there will be a quiz 00:03:13.409 --> 00:03:17.450 at the end dealing with the laboratory, so just be prepared. 00:03:17.450 --> 00:03:20.309 Give you a number of examples – hopefully not too many. 00:03:20.309 --> 00:03:21.879 There are quite a few slides. 00:03:21.879 --> 00:03:24.730 Show the link between the field and the lab – that’s where the quiz is 00:03:24.730 --> 00:03:31.309 coming from – and just a couple remarks. Okay, so basically, when we first started 00:03:31.309 --> 00:03:37.459 [chuckles] in the late ’60s, early ’70s, you know, we’d have boreholes 00:03:37.459 --> 00:03:40.480 and so forth, and you’d have a shear wave velocity profile 00:03:40.480 --> 00:03:44.849 with measuring shear waves directly and a compression wave. 00:03:44.849 --> 00:03:47.819 And the thing that’s – from an engineering point of view, typically, 00:03:47.819 --> 00:03:50.980 it’s the shearing that matters. But if you want to know the soil 00:03:50.980 --> 00:03:54.980 characteristics more or less, P and S are just as good if 00:03:54.980 --> 00:03:57.480 you’re above the water table. But sooner or later, you get below 00:03:57.480 --> 00:04:02.460 the water table and in the soils, and even in fractured rock, that’ll 00:04:02.460 --> 00:04:07.339 mislead you as to the characteristics. So that’s why, in the engineering part, 00:04:07.340 --> 00:04:10.440 we’ve spent so much time on shear waves. 00:04:10.440 --> 00:04:15.559 And for us, surface waves are close enough to shear waves. 00:04:15.559 --> 00:04:19.090 We just have to do a little bit of work to get it to be shear wave velocity. 00:04:19.090 --> 00:04:24.389 In the lab, then, here’s shear modulus. There’s the small-strain shear modulus. 00:04:24.389 --> 00:04:28.840 I know they like to call it G-naught now, but since I grew up calling it G-max, 00:04:28.840 --> 00:04:31.370 the Europeans don’t change me. 00:04:31.370 --> 00:04:34.891 Here’s the small-strain shear modulus, the mass density. 00:04:34.891 --> 00:04:38.840 You can guess that probably within 10 – at most 15%. 00:04:38.840 --> 00:04:42.480 But you can’t guess that worth a hoot, so that’s why you’ve got to measure 00:04:42.480 --> 00:04:46.949 shear wave velocity to come up with a decent idea of that starting point. 00:04:46.949 --> 00:04:49.870 And then that’s what’s determined in the lab, although we’re doing 00:04:49.870 --> 00:04:54.280 some of that in the field now, even on constrained compression waves. 00:04:54.280 --> 00:04:56.300 And here’s D-min. 00:04:56.300 --> 00:05:02.120 So small-strain damping and how it changes with strain amplitude. 00:05:02.120 --> 00:05:08.160 Damping is much more strain-dependent, by a factor of 2 or 3, than modulus. 00:05:08.160 --> 00:05:12.780 And you can get hysteretic damping and equivalent viscous damping. 00:05:12.780 --> 00:05:17.420 That’s a different talk. But we measure both in the lab. Next. 00:05:17.420 --> 00:05:21.600 See, I’m trying to get invited back. That’s what that’s all about. Okay. 00:05:21.610 --> 00:05:23.919 So body waves. You know, we’re just going to 00:05:23.920 --> 00:05:28.880 put the energy we want. So we need to have a good source. 00:05:28.880 --> 00:05:33.160 Measurements at different points, knowing distances, looking at times, 00:05:33.160 --> 00:05:36.720 we come up with the velocities. Next. 00:05:38.420 --> 00:05:40.919 And so compression and shear – and, you know, 00:05:40.920 --> 00:05:43.720 it’s interesting to think about it. 00:05:43.720 --> 00:05:49.540 Compression wave, particle direction, direction of propagation – the same. 00:05:50.680 --> 00:05:54.840 One coordinate needed to describe it. Shear waves – two coordinates. 00:05:54.840 --> 00:05:58.000 Shear waves are much more complex than compression waves. 00:05:58.000 --> 00:06:01.389 Shearing, depending on how you load it, is more complex. 00:06:01.389 --> 00:06:05.250 I’ll just leave it that way. Yep. That was fine. 00:06:05.250 --> 00:06:08.419 And for us in geotechnical engineering, you know, we’re looking at a 00:06:08.419 --> 00:06:11.650 stress-strain curve, and that’s the initial slope. 00:06:11.650 --> 00:06:18.590 And when I was a young man quite a few years ago, that – 00:06:18.590 --> 00:06:25.490 here you see 5/100ths of a percent, 1/10 of a percent, and so forth. 00:06:25.490 --> 00:06:29.190 That would be the very first point you measured in triaxial testing. 00:06:29.190 --> 00:06:30.900 That would be the very first point. 00:06:30.900 --> 00:06:35.150 And so, when we started coming up with numbers for shear stiffness, 00:06:35.150 --> 00:06:39.150 they all thought we were crazy by about a factor of 10 or something. 00:06:39.150 --> 00:06:41.880 But they learned we weren’t. Next. 00:06:42.520 --> 00:06:47.800 For us today, again, for me, this is the gold standard, 00:06:47.800 --> 00:06:51.340 and I can defend it to be that, but we won’t in this talk. 00:06:51.340 --> 00:06:54.759 But crosshole is not used that much. Why? Because of the expense 00:06:54.759 --> 00:06:58.139 of drilling three boreholes. So that’s very understandable. 00:06:58.139 --> 00:07:04.289 Downhole, the seismic cone, also the seismic dilatometer, are used more. 00:07:04.289 --> 00:07:10.949 And it’s interesting because you really should pay attention to the wavelengths 00:07:10.949 --> 00:07:16.490 that you’re generating in these tests. They aren’t that much done today yet. 00:07:16.490 --> 00:07:19.499 But I think they will have to. But that’s used a lot. 00:07:19.499 --> 00:07:23.310 You might be making measurements over this distance and implicitly think 00:07:23.310 --> 00:07:25.150 you’re sampling that distance, and you’re not. 00:07:25.150 --> 00:07:27.880 But I won’t defend that any more than that right now. 00:07:27.880 --> 00:07:31.680 The P-S suspension logger – so a wire line device. 00:07:31.689 --> 00:07:36.259 That’s used a great deal, particularly for deep measurements. 00:07:36.259 --> 00:07:40.139 And then surface waves. And surface waves – the Rayleigh type 00:07:40.139 --> 00:07:47.919 that we’re talking about here – are used a lot because they’re non-intrusive. 00:07:47.919 --> 00:07:53.570 So that makes them very economical. You can sample large areas with them, 00:07:53.570 --> 00:07:57.669 whether they’re large areas shallowly or large areas deeply. 00:07:57.669 --> 00:08:03.229 They have the capability of evolving even more than they have, 00:08:03.229 --> 00:08:06.710 doing three-dimensional prospecting and so forth. 00:08:06.710 --> 00:08:11.490 Because they’re theoretically sound – as in – all geophysical testing is. 00:08:11.490 --> 00:08:14.819 But they’re theoretically sound, so things will develop. 00:08:14.819 --> 00:08:18.370 And I expect to see this just continue more and more. 00:08:18.370 --> 00:08:20.120 Next. And that’s what we’re going to talk about. 00:08:20.120 --> 00:08:23.820 So I’m going to give you just an overview. 00:08:23.820 --> 00:08:28.379 If you’ll not be too offended, I’m going to use spectral analysis of surface waves, 00:08:28.379 --> 00:08:32.599 just because that’s what we do, but there are various techniques out there. 00:08:32.600 --> 00:08:36.660 And I’m not trying to make any comparisons at all. 00:08:36.660 --> 00:08:41.700 But you’re going to – you impart energy with surface waves in general. 00:08:41.700 --> 00:08:44.560 At one location, you might have multiple receivers. 00:08:44.560 --> 00:08:48.300 We look at wavelengths, so we’re always working in receiver pairs. 00:08:48.300 --> 00:08:51.880 And it’s really the things that started surface waves. 00:08:51.880 --> 00:08:55.750 This method and others have continued. 00:08:55.750 --> 00:09:00.630 The thing that’s so nice about them, you’re stressing a zone that is 00:09:00.630 --> 00:09:03.540 dependent upon the wavelength. And so this would be like 00:09:03.540 --> 00:09:06.400 the wavelength – we’ll show it in a moment. 00:09:06.400 --> 00:09:08.460 And all that wave would see is the first layer. 00:09:08.460 --> 00:09:11.290 This wave sees the first and second layers, but not that much. 00:09:11.290 --> 00:09:14.200 And then you do a forward modeling or an inversion process 00:09:14.200 --> 00:09:17.820 to try to get out the shear wave velocity profile. Next. 00:09:17.820 --> 00:09:21.190 So in the field, you’ve got that wavelength and this, 00:09:21.190 --> 00:09:23.530 and you’re looking at a phase velocity. 00:09:23.530 --> 00:09:26.300 So this is the velocity that you’re watching go by. 00:09:26.300 --> 00:09:31.200 Now, it can have body waves in it too, but that can – it can’t be separated 00:09:31.200 --> 00:09:37.160 as easily, but it can be dominated by the Rayleigh wave so that that’s – 00:09:37.160 --> 00:09:41.500 that is the bulk of this curve. And this would be normally dispersive, 00:09:41.500 --> 00:09:43.820 meaning that it’s getting stiffer with depth. 00:09:43.820 --> 00:09:47.620 And you just – we’re trying to measure this curve in situ – 00:09:47.620 --> 00:09:53.490 or evaluate it in situ that we then can model in the – back in the office. 00:09:53.490 --> 00:10:00.440 For us, we typically pick a center point. And you want to know what’s 00:10:00.440 --> 00:10:04.300 near the surface, so you have close receiver spacings. 00:10:04.300 --> 00:10:09.370 We like to keep the distance between the source and first receiver equal to X. 00:10:09.370 --> 00:10:12.620 Then another X here. And then 2X there, and so you 00:10:12.620 --> 00:10:16.100 just keep going larger and larger. Of course, you’re making an assumption 00:10:16.100 --> 00:10:22.610 that the top layers are continuous along the way, however, when you 00:10:22.610 --> 00:10:26.930 start getting long wavelengths, what’s up here has almost no effect. 00:10:26.930 --> 00:10:34.160 So they’re counteracting effects here, but you can get a very good profile 00:10:34.160 --> 00:10:38.650 for many, many applications following a procedure like this. 00:10:38.650 --> 00:10:43.160 Or you can, like, MASW, put a bunch of receivers out 00:10:43.160 --> 00:10:46.580 and watch the waves propagate along there. 00:10:46.580 --> 00:10:49.540 The thing that concerns me about that is, 00:10:49.540 --> 00:10:53.680 you’re getting near-field and far-field effects in that whole measurement. 00:10:53.680 --> 00:10:58.180 We can discuss that more one-on-one if you want later on. 00:10:58.180 --> 00:11:01.100 And that can distort the measurement a bit. 00:11:01.100 --> 00:11:02.640 Next. 00:11:02.640 --> 00:11:06.040 Okay, typically, when we’re doing things 00:11:06.050 --> 00:11:10.770 at deeper sites, we’re using 1 hertz geophones. 00:11:10.770 --> 00:11:13.300 They’re phase-matched. That means we calibrate them – 00:11:13.300 --> 00:11:17.010 I’m sorry it’s missing from here – they’re phase match. 00:11:17.010 --> 00:11:22.730 And we calibrate all of those in the lab so that, when you’re in the field, 00:11:22.730 --> 00:11:27.510 and you’re using pairs, you don’t – you’ll get geophones that will go out on you. 00:11:27.510 --> 00:11:29.880 You’ll get geophones, particularly the bigger ones, 00:11:29.880 --> 00:11:33.220 that you have to be more careful handling them. 00:11:33.220 --> 00:11:36.750 But to make sure they’re phase-matched over the range that 00:11:36.750 --> 00:11:40.280 you’re doing is an important factor. Next. 00:11:41.180 --> 00:11:46.100 And, you know, we would always – so we start with short spacings 00:11:46.100 --> 00:11:50.820 and go to longer ones. We’re always using hammers at the start. 00:11:50.820 --> 00:11:56.350 Those are the easiest things to use. They generate a nice transient frequency 00:11:56.350 --> 00:12:00.250 content that you – that you need in here. So, you know, we’ve got – 00:12:00.250 --> 00:12:02.980 those are 1 hertz receivers. That’s a total station because 00:12:02.980 --> 00:12:07.080 it’ll be going long distances. You’ll see that in a minute. Next. 00:12:10.010 --> 00:12:13.380 By the way, just for the record – so we have quite a few vibes. 00:12:13.380 --> 00:12:16.420 I won’t show you all of them. You can thank me for that. 00:12:16.420 --> 00:12:21.300 But this is Liquidator – one of my favorites. 00:12:21.300 --> 00:12:28.120 And it’s one of a kind because most Vibroseises, you know, 00:12:28.130 --> 00:12:31.830 in the oil exploration business – well, just in the geophysical exploration 00:12:31.830 --> 00:12:36.480 business, they have strokes like this. And Liquidator has a stroke like that. 00:12:36.480 --> 00:12:39.390 It still isn’t enough for me, but you’ll see what happens 00:12:39.390 --> 00:12:44.470 when you need a – you need more. But that right in there that is more – 00:12:44.470 --> 00:12:46.870 that’s sort of a Tennessee orange. A little bit like this. 00:12:46.870 --> 00:12:51.790 We’ll see a Texas orange maybe on another one – a little darker. 00:12:51.790 --> 00:12:55.660 But everything that’s white and wheels and all that hold that down. 00:12:55.660 --> 00:12:59.650 And then the shaker in here, it can be rotated to be horizontal, 00:12:59.650 --> 00:13:04.180 but we’ve never done that. But it’s going vertically. 00:13:04.180 --> 00:13:09.440 And that big plate – and so you see, wow, those rods are holding it down. 00:13:09.440 --> 00:13:11.400 No, they’re not. Those are only guide rods. 00:13:11.400 --> 00:13:14.870 There are two little rods right here holding this 55,000 pounds 00:13:14.870 --> 00:13:18.670 on that plate so that it’s in good contact with the ground 00:13:18.670 --> 00:13:21.840 and you can generate nice energy. 00:13:21.840 --> 00:13:27.190 Now, it’s a little bit like – if you got a little drum, you get higher frequencies. 00:13:27.190 --> 00:13:29.880 If you got a bigger drum, you get lower frequencies. 00:13:29.880 --> 00:13:34.240 So it would be nice if the plate was maybe two or three times as big, but it’s 00:13:34.240 --> 00:13:38.480 going to take a nice budget from USGS before we can build something like that. 00:13:38.480 --> 00:13:41.980 [laughter] But it’s on my list of things to do. 00:13:41.980 --> 00:13:44.380 Okay, so here we are. We’re out at Hanford. 00:13:44.380 --> 00:13:48.120 It was the same site you saw the other stuff. Next, please. 00:13:48.120 --> 00:13:52.660 And, you know, so there’s Liquidator. We would be aiming on it to 00:13:52.660 --> 00:13:55.720 see how far away it is. You get tired of pacing all that and 00:13:55.720 --> 00:14:00.080 so forth, or stretching the tapes out. So that’s a easy thing to handle. 00:14:00.080 --> 00:14:04.750 I didn’t mention that the center geophone of those three doesn’t move. 00:14:04.750 --> 00:14:07.300 And so here it is. Next. 00:14:07.720 --> 00:14:12.860 And this is real data. So I’m going to be showing you lots of real data. 00:14:14.620 --> 00:14:16.660 So what kind of data is it? 00:14:17.420 --> 00:14:19.960 It’s our best data. Of course. 00:14:19.960 --> 00:14:23.240 I’m not going to show you our bad data. 00:14:23.240 --> 00:14:26.660 And it gets disappointing when you get that in the field, but that can 00:14:26.660 --> 00:14:31.170 happen just because of site conditions. Okay. So here we are. 00:14:31.170 --> 00:14:36.950 This is actual – this is a wrapped phase. So you’re determining in the field, in 00:14:36.950 --> 00:14:42.100 front of you, you’re watching the phase change – the phase shift being measured. 00:14:42.100 --> 00:14:44.060 And you’re starting from high frequencies 00:14:44.060 --> 00:14:46.730 and moving to low frequencies. 00:14:46.730 --> 00:14:51.590 And this point A right here just means we have a wave that looks just like that, 00:14:51.590 --> 00:14:56.320 and it’s one cycle. So one wavelength between those receivers. 00:14:56.320 --> 00:15:00.830 It is – it’s not going back to zero because we can’t generate that low of frequency. 00:15:00.830 --> 00:15:04.770 So here we cut it off. And look, we cut it off at about 1 hertz. 00:15:04.770 --> 00:15:08.620 And so that particular point right there – so that’s 180 degrees. 00:15:08.620 --> 00:15:13.360 That point and that point are the same. It’s just wrapped so you can look at it. 00:15:13.360 --> 00:15:18.620 And here we go. So we’ve got 180, another 180, 360. 00:15:18.620 --> 00:15:20.540 So we have 360 degrees. 00:15:20.540 --> 00:15:25.000 It’s 180-meter-long spacing between them. Here we are. 00:15:25.000 --> 00:15:30.980 That’s 4.37 hertz, 790 meters per second. So we’ve got that throughout all of this. 00:15:30.980 --> 00:15:36.300 Next. We’ll look at the same one. Okay, here’s B, here’s C. 00:15:36.300 --> 00:15:38.800 Those are different points on that waveform. 00:15:38.800 --> 00:15:41.120 We now are doing – I’m sorry because I sidetrack 00:15:41.120 --> 00:15:44.740 quite a bit – spectral analysis of body waves. 00:15:44.740 --> 00:15:46.240 Very important. 00:15:46.240 --> 00:15:49.040 Okay, but we’re on a surface wave talk. 00:15:49.040 --> 00:15:52.990 Okay, so these are the surface waves. And so there’s other energy in there, 00:15:52.990 --> 00:15:57.290 but it’s small compared to – generally, it’s small compared to the others. 00:15:57.290 --> 00:15:59.680 Now, you can get modes, and we’ll see that in a minute. 00:15:59.680 --> 00:16:00.920 Next. 00:16:01.300 --> 00:16:07.600 So for that one record that you saw there, one spacing between geophones, 00:16:07.610 --> 00:16:11.620 and that’s just two geophones because they work in pairs all the time. 00:16:11.620 --> 00:16:17.300 Okay, so here’s phase velocity. Here’s wavelength on a log scale. 00:16:17.300 --> 00:16:22.050 And that was A, B, and C on that point. And so you see there’s some complexity 00:16:22.050 --> 00:16:25.920 there that we’re going to just go through and ignore. 00:16:25.920 --> 00:16:31.740 And get average numbers. But that’s one receiver spacing. Next. 00:16:31.740 --> 00:16:34.680 This would be at – this is at Hanford now. 00:16:34.680 --> 00:16:39.020 And [chuckles] sorry for the units here. They’re not always this on all the slides. 00:16:39.020 --> 00:16:43.700 But, you know, here’s a short spacing. Now we’re – probably done this, 00:16:43.700 --> 00:16:46.800 all of that, and maybe even some of this with a hammer. 00:16:46.800 --> 00:16:52.540 And now we get the vibe in there, and you can see – in fact, they’re all – 00:16:52.540 --> 00:16:56.240 this is the nice part. Can you erase this from the video? 00:16:56.240 --> 00:16:59.790 This is the nice part about having graduate students. 00:16:59.790 --> 00:17:03.870 You see how all – they’re color-coded and everything like that? 00:17:03.870 --> 00:17:06.050 So you can see exactly where they all come from, 00:17:06.050 --> 00:17:08.310 and you see how they fit together. 00:17:08.310 --> 00:17:11.110 And basically, you really didn’t see much of a mode. 00:17:11.110 --> 00:17:13.150 Maybe a mode was coming in here and so forth. 00:17:13.150 --> 00:17:15.589 And we’re going to go – just go through the center of that. 00:17:15.589 --> 00:17:20.300 So we’re averaging. And you can do more sophisticated analyses, that’s fine. 00:17:20.300 --> 00:17:23.000 But this just shows you typical data, and you can see there’s – 00:17:23.000 --> 00:17:28.060 860 meters was the longest wave. And we would go to half of that 00:17:28.060 --> 00:17:32.450 length when we plot a profile. We wouldn’t go to that length because 00:17:32.450 --> 00:17:36.240 you don’t know what’s going on up here. So you can’t do that. Next. 00:17:37.070 --> 00:17:41.680 So that’s the same here in the – in the pale blue – that’s the 00:17:41.680 --> 00:17:45.540 same as what you just saw there. So that’s all the field data. 00:17:45.540 --> 00:17:50.120 And then you would start out in a forward modeling, and there’s 00:17:50.120 --> 00:17:53.180 inversion done with this as well. But in forward modeling, 00:17:53.180 --> 00:17:55.580 you know what to start with. You got the numbers right there. 00:17:55.580 --> 00:17:58.240 It’s not a big deal. And you just build layers. 00:17:58.240 --> 00:18:03.420 And so what you see is, this is the shear wave velocity profile. 00:18:03.420 --> 00:18:06.900 And I apologize. I didn’t realize it was that coarse. 00:18:06.900 --> 00:18:11.230 But, at any rate – I mean up here – but, at any rate, there’s a velocity, 00:18:11.230 --> 00:18:14.870 then there’s a layer dip. There’s a velocity, a layer dip, then so forth. 00:18:14.870 --> 00:18:18.360 And the layers are going to get thicker the deeper you go 00:18:18.360 --> 00:18:22.970 in a simple profiling like this because you start losing resolution. 00:18:22.970 --> 00:18:25.460 You can’t – you can’t capture it. 00:18:25.720 --> 00:18:31.240 The work – I’m not, but others are doing 3D profiles in this sort of work 00:18:31.240 --> 00:18:35.350 [chuckles] and they might have the computer grinding for, you know, a day. 00:18:35.350 --> 00:18:39.960 That’s a Texas Stampede. Some of the supercomputers we have. 00:18:39.960 --> 00:18:43.960 And – I’m told. I don’t get out there and use them. 00:18:43.960 --> 00:18:49.240 But you can improve that a little bit, but whether you need to or not 00:18:49.240 --> 00:18:52.480 all depends on the complexity and the data. 00:18:53.460 --> 00:18:56.600 Okay, here are the examples. And hopefully each one of these 00:18:56.602 --> 00:18:59.350 examples is going to show you something a little different 00:18:59.350 --> 00:19:03.410 and hopefully make it worthwhile. So Dillon Dam in Colorado, 00:19:03.410 --> 00:19:08.530 Vogtle nuclear power plant, the Big Island of Hawaii – oh – USGS. 00:19:08.530 --> 00:19:12.780 Yucca Mountain, west Texas, Greenfield site. 00:19:13.660 --> 00:19:16.720 Here’s Dillon Dam in Dillon, Colorado. 00:19:16.720 --> 00:19:21.700 One of the main reservoirs supplying the best water to Denver. 00:19:21.700 --> 00:19:28.820 And the question was, it is an embankment dam with a 00:19:28.820 --> 00:19:34.730 low permeability core, and, you know, downstream and upstream shells made 00:19:34.730 --> 00:19:40.840 out of the alluvium that was sieved, so to speak, so that anything bigger 00:19:40.840 --> 00:19:46.620 than 1 foot in diameter, in theory, would be cut out and – building these. 00:19:46.620 --> 00:19:52.560 And this was in the requalification of the dam quite a few years ago now. 00:19:52.560 --> 00:19:57.180 I mean – but that might not be that much – five, seven, 10 years ago. 00:19:58.360 --> 00:20:01.980 Did the contractor do a good job in these areas? 00:20:01.980 --> 00:20:06.460 And so I live in Texas. I grew up in Michigan. 00:20:06.460 --> 00:20:09.300 I shoveled all the snow I wanted to shovel. 00:20:09.300 --> 00:20:17.059 And what they said is, well, we can – when it freezes over, we can cut 00:20:17.059 --> 00:20:20.610 grooves in the ice, cut the ice, you can drop stuff down here, 00:20:20.610 --> 00:20:23.580 and I’m going, whoa, whoa, whoa. Before we do anything like that, 00:20:23.580 --> 00:20:26.050 why don’t you see if we can do a good job down here, 00:20:26.050 --> 00:20:30.000 and then maybe you’ll fire us, and we won’t have to go through all that. 00:20:30.000 --> 00:20:33.030 Or maybe you’ll say, oop, it looks like it’s good. 00:20:33.030 --> 00:20:37.860 So what we are doing here, and we do this quite a bit, 00:20:37.860 --> 00:20:42.581 is to estimate what the material is like is, we estimate what a good shear wave 00:20:42.581 --> 00:20:45.710 velocity profile would look like for that material. 00:20:45.710 --> 00:20:49.400 And then we see what the field shows us, and oop, there’s a problem. 00:20:49.400 --> 00:20:52.650 And this is really good stuff. And that seems plenty good. 00:20:52.650 --> 00:20:55.520 This is a different case where maybe they’ve done dynamic 00:20:55.520 --> 00:21:00.920 compaction or something, dropping a 20-ton weight 100 feet and so forth. 00:21:00.920 --> 00:21:04.559 And they want to know how improved that zone was. 00:21:04.559 --> 00:21:09.100 So again, using shear wave velocities, shear stiffnesses. 00:21:09.100 --> 00:21:13.690 So we’re looking at this in that fashion to evaluate the quality. 00:21:13.690 --> 00:21:16.720 Here is the reservoir. There’s the crest. 00:21:16.720 --> 00:21:19.230 And we started out working downstream 00:21:19.230 --> 00:21:24.680 but also on the downstream face. And that’s just an idealized profile. 00:21:24.680 --> 00:21:27.840 Didn’t used to be able to show you that, and I haven’t improved it, but now 00:21:27.840 --> 00:21:31.600 I can tell you it’s Dillon Dam. So that’s nice. 00:21:31.600 --> 00:21:37.690 Okay, here are our testing arrays. Downstream area. 00:21:37.690 --> 00:21:41.050 Just near a fence – you’ll see in the – in the slide. 00:21:41.050 --> 00:21:45.140 Right at the toe. And then on the downstream face. 00:21:45.140 --> 00:21:50.400 So it’s all coming in and out of the plane of the boards that we’re testing. Next. 00:21:51.200 --> 00:21:52.700 There’s our source. 00:21:52.700 --> 00:21:56.880 And so many times, we’ll use a bulldozer as a source. That’s a good source. 00:21:56.880 --> 00:22:00.570 And the client pays for it. We don’t have to put it in our budget, 00:22:00.570 --> 00:22:03.460 so it looks smaller, and that’s always helpful. 00:22:03.460 --> 00:22:05.650 Mm-hmm, particularly if you’re working with Ivan Wong because the 00:22:05.650 --> 00:22:09.660 budgets tend to be quite large. Okay. [laughter] Enough of that. 00:22:09.660 --> 00:22:13.360 Holy moly, that was recorded, wasn’t it? [laughter] 00:22:13.360 --> 00:22:17.510 You’re going to have to cover for me. Okay, and here’s a drill rig. 00:22:17.510 --> 00:22:20.640 And you know what the drill rig did? Nothing. 00:22:21.620 --> 00:22:24.400 Well, they did one good thing. They built these ramps that we 00:22:24.410 --> 00:22:27.600 could go up on with the bulldozer and use it as a source. 00:22:27.600 --> 00:22:31.900 But you see all those – they’re cobbles and maybe even getting to be a little bit 00:22:31.900 --> 00:22:36.090 of a boulder there that, when they were building the dam, it was, like, you know, 00:22:36.090 --> 00:22:38.500 I don’t – to be honest, I don’t know the exact things, 00:22:38.500 --> 00:22:41.040 but say the layer thickness was more than a foot. 00:22:41.040 --> 00:22:44.600 And then, when they compacted it, it was getting down a foot-thick layers. 00:22:44.600 --> 00:22:48.090 And so when any of the rocks were bigger, the dozer would 00:22:48.090 --> 00:22:49.960 sort of pick them out. You know, they throw them 00:22:49.960 --> 00:22:53.870 over the side, roll them down the dam. So that’s what you see there. Next. 00:22:53.870 --> 00:22:56.960 And that was the fence – back one, please, Alex? Thank you. 00:22:56.960 --> 00:23:00.480 That’s the fence that I mentioned to you. Next. 00:23:00.480 --> 00:23:05.720 Okay, that shows you typical material that we’re looking at. 00:23:05.730 --> 00:23:10.300 You know, it’s – here’s D-50, and it’s almost cobble size. 00:23:10.300 --> 00:23:14.309 This is not easy to sample. We won’t go into all that stuff. 00:23:14.309 --> 00:23:17.140 But let’s just say that’s not easy to sample. 00:23:17.140 --> 00:23:19.740 Wow. That’s an interesting slide. 00:23:20.440 --> 00:23:22.300 What the heck happened? 00:23:22.300 --> 00:23:24.400 - It looks the same on here. 00:23:27.480 --> 00:23:30.740 - This was the best data I could show you. [laughter] 00:23:30.750 --> 00:23:33.950 And I’m sorry it didn’t come out. 00:23:33.950 --> 00:23:36.950 What the heck? Okay, let’s keep going. 00:23:36.950 --> 00:23:39.760 That was – I can tell you what that was. That was all the profiles 00:23:39.760 --> 00:23:43.120 in the natural alluvium. And we don’t really need it. It’s okay. 00:23:43.120 --> 00:23:47.350 Because it’s – the median of – in fact, it’s the mean – the mean of 00:23:47.350 --> 00:23:51.840 that line is the dashed gray line. And then here it is in the dam. 00:23:51.840 --> 00:23:56.320 So up on the face of the dam, here – there are fewer sites, but here we 00:23:56.320 --> 00:24:00.740 are with the shear wave velocities. And don’t think, oh, look at – 00:24:00.740 --> 00:24:05.880 they can’t have a hitch in the natural alluvium and the dam at the same point. 00:24:05.880 --> 00:24:08.750 No. It’s the layering that we used in analyzing. 00:24:08.750 --> 00:24:11.460 So that just comes out by chance. 00:24:11.460 --> 00:24:13.170 But you see they’re just alike. 00:24:13.170 --> 00:24:16.550 You see 1,000 feet per second or 300 meters per second. 00:24:16.550 --> 00:24:19.700 So the natural alluvium is stiff. That means it’s dense. 00:24:19.700 --> 00:24:23.320 Well, it could mean it’s cemented, but I’ll prove to you it isn’t. 00:24:24.180 --> 00:24:27.620 The compacted alluvium in the dam is similar to the natural alluvium. 00:24:27.620 --> 00:24:30.680 So the contractor did a good job. 00:24:32.060 --> 00:24:33.780 No loose zones. 00:24:33.780 --> 00:24:39.580 Average COV – attenzione – that’s about my Italian – 0.1. 00:24:39.580 --> 00:24:44.680 COVs – even in alluvium like that, when you start having reasonable 00:24:44.680 --> 00:24:50.080 wavelengths, are low. They’re not 0.3. Okay, next? 00:24:50.860 --> 00:24:52.620 What the heck? 00:24:54.800 --> 00:25:00.180 Now, I’m – I better be careful. I asked the people that put these 00:25:00.190 --> 00:25:03.570 together, did they go through them and look at them, and they said they did. 00:25:03.570 --> 00:25:05.250 But that’s – this has never happened to me. 00:25:05.250 --> 00:25:08.240 I’ve shown these slides 20 times. Next. 00:25:10.520 --> 00:25:14.040 - The next one works. - The next one works after this? 00:25:14.040 --> 00:25:16.600 Well, that’s the end of my story. Keep going. 00:25:16.600 --> 00:25:20.059 Well, this could be a faster talk than I thought [laughter] 00:25:20.059 --> 00:25:24.700 if we don’t have anything in it. Okay, back one, please? [chuckles] 00:25:24.700 --> 00:25:26.670 Let me tell you what this showed you. [laughter] 00:25:26.670 --> 00:25:30.090 Here was a log – a shear wave velocity log confining pressure – 00:25:30.090 --> 00:25:35.179 oh, not on that one, but on this. And here’s an equation – dang it. 00:25:35.180 --> 00:25:39.480 There’s a vertical line on here, and we’ll see it – I hope we will see it. 00:25:39.480 --> 00:25:43.480 We’ll see it when we look at Vogtle nuclear power plant. 00:25:43.490 --> 00:25:47.160 Because vertical means you’ve nailed it. It’s a uniform material. 00:25:47.160 --> 00:25:50.360 And that equation describes the material, okay? 00:25:50.360 --> 00:25:56.240 And that equation says, at 1 atmosphere, Vs is 380 meters per second. Next. 00:25:56.240 --> 00:26:01.040 Here we are. Andrus and Stokoe, you know, earthquake, 00:26:01.050 --> 00:26:04.740 stress-corrected shear wave velocity, liquifies, doesn’t liquify. 00:26:04.740 --> 00:26:07.300 380 meters per second is what you see for that. 00:26:07.300 --> 00:26:12.480 Boom, it’s off the chart. It will not liquify in any earthquake. 00:26:13.360 --> 00:26:15.780 That’s what that says. Next. 00:26:16.680 --> 00:26:20.440 Ah. So I’ll try to remember to pop in this one. 00:26:20.450 --> 00:26:22.700 Okay, here’s Vogtle Electric Generating Plant – 00:26:22.700 --> 00:26:25.620 the nuclear power plant near Augusta, Georgia. 00:26:25.620 --> 00:26:31.360 It’s the first two nuclear plants being brought online in this century. 00:26:32.660 --> 00:26:36.000 And they’re being constructed right here. Next. 00:26:36.680 --> 00:26:43.200 And what you see is, here they – in Vogtle – and the first ones too – 00:26:43.200 --> 00:26:47.940 they had to excavate about 90 feet of material and then 00:26:47.940 --> 00:26:52.200 put in engineered fill to place the nuclear power plants because it was so poor. 00:26:52.200 --> 00:26:55.780 But they liked the site, so it was done. 00:26:55.780 --> 00:26:59.500 And now, with the new nuclear power plants that are being built – 00:26:59.500 --> 00:27:04.491 and I don’t know if any more are being built right now – but they were 00:27:04.491 --> 00:27:09.200 all designed – there are about four manufacturers – maybe three now. 00:27:09.200 --> 00:27:12.170 They were all designed to have a shear wave velocity 00:27:12.170 --> 00:27:16.580 of 1,000 feet per second at the base of the nuclear island. 00:27:16.580 --> 00:27:21.640 So that had never been done before, and so the contractor now had to 00:27:21.640 --> 00:27:26.240 deal with Professor Stokoe. The contractor didn’t like that. 00:27:26.240 --> 00:27:30.060 All we need is density. No. The design includes 00:27:30.060 --> 00:27:32.320 shear wave velocity. Uhhh-uhhh. 00:27:32.320 --> 00:27:39.220 So I said, okay, well, don’t – I said, like this, sort of talking to my wife. 00:27:39.220 --> 00:27:42.660 Don’t worry. It’ll work out. 00:27:42.660 --> 00:27:47.400 And the contractor said, I hate dealing with an academician. 00:27:47.400 --> 00:27:50.340 Almost used those words. 00:27:50.350 --> 00:27:56.810 But we would test these in – you see, 25 feet, we’d run surface wave tests. 00:27:56.810 --> 00:28:00.010 25 feet, run surface wave tests at the base of the nuclear island. 00:28:00.010 --> 00:28:03.800 20 feet, 20 feet. So we would march along, 00:28:03.800 --> 00:28:06.520 and we’d have to report to them, oh, looks good to me. 00:28:06.520 --> 00:28:10.559 I said that all the time, but they didn’t even know what it meant. 00:28:10.560 --> 00:28:11.920 But keep going. 00:28:11.920 --> 00:28:14.080 Okay, so here we are. 00:28:14.080 --> 00:28:16.120 I’ll show you what it means in a minute. 00:28:16.120 --> 00:28:21.360 Here’s the excavation going on, and there’s the two existing plants. 00:28:21.360 --> 00:28:24.000 And here is the backfill coming up. 00:28:24.010 --> 00:28:27.200 And we’d be – we would be doing our measurements. 00:28:27.200 --> 00:28:31.390 And when we were out there at those different times – I can’t make 00:28:31.390 --> 00:28:34.040 measurements when all the vibration is going on. 00:28:34.040 --> 00:28:37.160 So over the loudspeaker, stop all the vibrations. 00:28:37.160 --> 00:28:40.290 So everybody would stop. Woo. Do you feel like you 00:28:40.290 --> 00:28:43.950 have power at that point, huh? Everything stopped. 00:28:43.950 --> 00:28:49.120 And then we’d – zzzzttt. And, okay, and off they would go. Next. 00:28:49.760 --> 00:28:51.920 This – I like this. By the way, I took none of these. 00:28:51.920 --> 00:28:54.610 These are compliments of Southern Company. 00:28:54.610 --> 00:28:57.220 But here’s one nuclear island. Here’s another nuclear island. 00:28:57.220 --> 00:28:58.850 You see the base of it. 00:28:58.850 --> 00:29:01.920 And you see – this is a select fill that we really are involved with – 00:29:01.920 --> 00:29:04.440 that different – that lighter color right there. 00:29:04.440 --> 00:29:08.059 And you – it’s complex. Next. 00:29:08.059 --> 00:29:11.640 So here we are at the last of the four times we went there. 00:29:11.640 --> 00:29:14.590 And again, we were using a dozer and geophones. 00:29:14.590 --> 00:29:17.940 And that’s the biggest crane in the world at that time being built with a bunch of 00:29:17.940 --> 00:29:22.560 cranes so that they could put stuff in each nuclear island from the same crane. 00:29:22.560 --> 00:29:24.540 Next. - I got some bad news. 00:29:25.920 --> 00:29:34.140 - This is going to make me mad as hell. - All the next ones are [inaudible]. 00:29:35.480 --> 00:29:39.340 - Well, this will get over early. Let’s see what comes up. 00:29:39.340 --> 00:29:42.480 This – I have never had this happen in my life. 00:29:44.660 --> 00:29:49.460 - Should I open a different file instead? [inaudible]. 00:29:52.720 --> 00:29:56.240 - I guess I better stop swearing, because this is on video. 00:29:56.240 --> 00:30:00.000 Let’s go back one. - Here? 00:30:00.400 --> 00:30:01.640 - Another one. 00:30:02.200 --> 00:30:03.940 Another one. 00:30:06.560 --> 00:30:09.020 Go backwards. [laughs] 00:30:09.020 --> 00:30:13.040 Okay. This was going to be one of my favorite to show you. 00:30:13.040 --> 00:30:14.800 Now, what is it? 00:30:14.800 --> 00:30:19.980 This shows you the COV on the materials in the 90 feet. 00:30:19.980 --> 00:30:24.700 And it shows you, in both – because units 3 and – unit 3 and unit 4 – 00:30:24.700 --> 00:30:32.320 that the COV, in the best you could get – built material, and with this surface 00:30:32.330 --> 00:30:38.760 wave evaluation, are, by 0.05 and 0.04. So don’t expect to get anything, 00:30:38.760 --> 00:30:44.400 in my mind, less than that in nature, huh? Well, there’s always exceptions. 00:30:44.400 --> 00:30:47.960 But that was one thing I was trying to show you there. Next. 00:30:48.780 --> 00:30:53.080 This is going to go down in history as my worst talk ever. 00:30:53.080 --> 00:30:55.340 We got to erase all of it. Keep going. 00:30:56.380 --> 00:30:57.640 Keep going. 00:30:57.640 --> 00:31:00.520 Do you want to take a look at this, Alan, and see if it’s on here? 00:31:00.520 --> 00:31:04.020 But we won’t have time to do it anyway, so … 00:31:04.020 --> 00:31:09.100 - We could burn it to PDF or something [inaudible]. 00:31:10.660 --> 00:31:15.600 - It’s a PDF file. It’s a PowerPoint file. 00:31:16.380 --> 00:31:19.200 - [inaudible] because I know you don’t work on a Mac. 00:31:19.900 --> 00:31:23.500 - You’re right. - [inaudible] 00:31:25.200 --> 00:31:31.020 [Silence] 00:31:31.020 --> 00:31:33.100 - That’s okay. 00:31:34.780 --> 00:31:40.040 You know, I worked very hard on this to have key points 00:31:40.040 --> 00:31:42.620 that hopefully would b e interesting to you. 00:31:42.620 --> 00:31:45.220 - While you have a moment … - Yes, sir? 00:31:45.220 --> 00:31:49.370 - … what were you filling with? - Oh, it’s a select engineered fill, 00:31:49.370 --> 00:31:52.940 and it’s a sand to a silty sand. 00:31:54.260 --> 00:32:03.160 And it is the highest quality that they have and – for that site, that’s passed, 00:32:03.170 --> 00:32:14.169 and it’s go no plasticity. And it’s more of an SP to an SM 00:32:14.169 --> 00:32:18.320 material, if that makes sense to you in geotechnical – okay, fine. 00:32:18.320 --> 00:32:20.710 That would be – no problem. That’s a gradation curve that looks 00:32:20.710 --> 00:32:25.890 something like that to a gradation curve that has a little more silt in it here. 00:32:25.890 --> 00:32:28.980 When we looked at all that gravel, which would be way over here. 00:32:28.980 --> 00:32:32.450 That alluvium would be way over here. We’re way over on the other side. 00:32:32.450 --> 00:32:38.040 Let’s keep going, and if we find things – okay, let me just say another thing. 00:32:38.040 --> 00:32:43.290 In terms of what we’ve done, you know, that one – that’s dynamic compaction, 00:32:43.290 --> 00:32:46.429 and that was the one where I showed you, okay, here was the shear wave 00:32:46.429 --> 00:32:51.049 velocity profile, and then it changed. So it went up here like this near the top. 00:32:51.049 --> 00:32:53.590 So we were compacting. And you’ll find that you can pack 00:32:53.590 --> 00:32:58.100 down maybe 30 or 40 feet at most with these big – that’s a multi – 00:32:58.100 --> 00:33:05.180 that’s a 20-ton weight that’s dropped 30 – 100 feet – something like that. 00:33:05.190 --> 00:33:09.210 Here is a landslide. It was the second landslide we’ve ever done. 00:33:09.210 --> 00:33:14.720 The first landslides we’ve done were for Les Youd at Mount St. Helens. 00:33:14.720 --> 00:33:18.220 And the natural impoundment, so we went to three. 00:33:18.230 --> 00:33:22.210 And did they look good, did they look bad. Yes. 00:33:22.210 --> 00:33:26.470 Not all were good, not all were bad, huh, so it varied. 00:33:26.470 --> 00:33:32.200 This is a mile from here to there. That’s Valtellina. 00:33:32.200 --> 00:33:35.870 Up here is their main ski resort. This was done a long time ago. 00:33:35.870 --> 00:33:38.490 And the question is, was this dense down there? 00:33:38.490 --> 00:33:41.540 And so, do we have any guesses? 00:33:43.160 --> 00:33:45.560 No guesses. Yes, it’s dense. 00:33:45.560 --> 00:33:50.660 Why is it dense? It’s dense because it came down a mile. 00:33:50.669 --> 00:33:53.380 There was a huge amount of energy put into that. 00:33:53.380 --> 00:33:55.820 And with surface waves – I mean, we had boulders, 00:33:55.820 --> 00:33:58.260 you know, around there, we’d have to have the bulldozer 00:33:58.260 --> 00:34:00.760 go around. They were huge. 00:34:00.760 --> 00:34:06.110 But it’s these earthquake lakes and so forth that are created. 00:34:06.110 --> 00:34:11.880 And I remember being in China just after one of the major earthquakes, 00:34:11.880 --> 00:34:16.180 and we were talking, and I said, wow, that’s where you should build your city, 00:34:16.190 --> 00:34:21.440 on that, and get rid of the lake behind it, so drain, because this is really dense, 00:34:21.440 --> 00:34:24.450 good material. And so Professor Ishihara, 00:34:24.450 --> 00:34:27.880 Japanese, was there and said, oh, we do that in Japan. 00:34:27.880 --> 00:34:33.500 And I say, dang, another good idea that I didn’t come first with. No problem. 00:34:33.500 --> 00:34:36.800 But it just made sense. Because you’d be surprised. 00:34:36.800 --> 00:34:40.700 Those impoundments that are created are very good. 00:34:40.700 --> 00:34:43.760 Does this mean how much time I have left? 00:34:45.180 --> 00:34:47.640 Okay, let’s see. 00:34:49.820 --> 00:34:53.140 Shall we just keep going and see what’s going on there? 00:34:53.140 --> 00:34:57.539 And remember, I was told to bring this because you had Macs. 00:34:58.780 --> 00:35:02.780 Do you see how I’m trying to deflect the problem there a little bit? 00:35:02.780 --> 00:35:06.470 Kottke, if you can get this working, you’re going to get a second Ph.D. 00:35:06.470 --> 00:35:08.670 [laughter] I’m telling you. 00:35:08.670 --> 00:35:14.900 Just – I got clout back at Texas. Only in my mind. [chuckles] 00:35:14.900 --> 00:35:18.300 Oh, USGS. Okay. 00:35:19.100 --> 00:35:22.480 This is another good example. And we can go back and hit a couple 00:35:22.489 --> 00:35:27.049 of the key points if we’re so lucky, but I won’t keep you too long. 00:35:27.049 --> 00:35:29.420 So here’s the Big Island of Hawaii. 00:35:29.420 --> 00:35:45.540 And we had the opportunity here to work with Mr. Wong on this project. 00:35:45.540 --> 00:35:52.060 And after – a year or two after the ’06 October earthquakes, 00:35:52.060 --> 00:35:55.619 go around and look at the seismic stations and 00:35:55.620 --> 00:35:59.480 try to look for Vs30, whether we like it or not. 00:35:59.480 --> 00:36:06.579 And so basically, what you see here, this basalt, we tested 22 stations around 00:36:06.579 --> 00:36:15.329 there. And out of those 22 stations, 19 are on basalt and are a site class B. 00:36:15.329 --> 00:36:18.299 So I’ll tell you the story before we finish. 00:36:18.299 --> 00:36:22.320 There are no site class B’s on the island that we tested. 00:36:22.320 --> 00:36:27.039 This is classic. We’re near the surface. Rock is much more fractured, 00:36:27.040 --> 00:36:31.940 hence much softer than you would think by looking at a geologic map. 00:36:31.940 --> 00:36:33.920 And this was just a great example. 00:36:33.920 --> 00:36:37.450 So here are the 22 stations. Next. 00:36:37.450 --> 00:36:40.979 On this particular one – so we’re rid of dozers. 00:36:40.979 --> 00:36:45.440 By the way, the only reason we’re rid of dozers is because, after the earthquake, 00:36:45.440 --> 00:36:49.029 you couldn’t even rent a dozer on that island, they were so expensive, 00:36:49.029 --> 00:36:52.480 as a matter of fact. So we shipped this machine over. 00:36:52.480 --> 00:36:55.210 It’s our smallest one. But it worked fine. 00:36:55.210 --> 00:37:00.500 So here we are up near the glacier. Here we are down amongst the flowers. 00:37:00.500 --> 00:37:01.760 Next. 00:37:01.760 --> 00:37:07.880 And here are all the profiles that we measured at the 22 sites. 00:37:07.880 --> 00:37:12.400 And these right here – these outliers are two of them right there in Hilo. 00:37:12.400 --> 00:37:15.819 And, you know, Hilo is in a deep alluvial valley – 00:37:15.819 --> 00:37:21.510 I mean, just of very soft materials. So I’m going to take those two out. 00:37:21.510 --> 00:37:25.319 Because that doesn’t count. We would know those shouldn’t be – 00:37:25.320 --> 00:37:29.300 and I don’t – they were not classified [chuckles] incorrectly. 00:37:29.300 --> 00:37:30.400 Next. 00:37:31.050 --> 00:37:36.000 So here’s the rest of the data. So it’s 20 sites out of the 22. 00:37:36.019 --> 00:37:37.550 And that’s all the data. 00:37:37.550 --> 00:37:42.599 Now – and you can see – oop. Wow. The COV gets higher 00:37:42.600 --> 00:37:46.460 near the surface, of course. Get more variability. 00:37:46.460 --> 00:37:51.319 The average is still pretty low with all this junk mixed together. 00:37:51.319 --> 00:37:55.470 This shows you the number of profiles that we would look at. 00:37:55.470 --> 00:37:57.410 And so we’re always interested in this. 00:37:57.410 --> 00:38:02.170 And, in fact, I think Walt Silva and Ivan Wong made a start doing this. 00:38:02.170 --> 00:38:06.080 I must give them credit. But I like it a lot. 00:38:06.080 --> 00:38:13.299 And so, if a geotechnical engineer looks at that, he wants to fiddle with it. 00:38:13.299 --> 00:38:15.760 Okay, let’s start fiddling. 00:38:15.760 --> 00:38:17.130 Next. 00:38:17.130 --> 00:38:23.540 So I’m going to – I’m going [chuckles] – this is unbelievable. 00:38:23.540 --> 00:38:26.500 Here’s dense sand. Here is dense gravel. 00:38:26.500 --> 00:38:28.960 Yeah, I know you can’t see it. That’s okay. It’s right here. 00:38:28.960 --> 00:38:30.620 There’s the equation. 00:38:30.620 --> 00:38:34.280 And here is my idea of unweathered basalt. 00:38:34.289 --> 00:38:40.420 And so up near the surface, I said it was 2,200 feet per second. 00:38:40.420 --> 00:38:44.740 And then the 2,500 feet per second was below 100 feet. 00:38:44.740 --> 00:38:48.190 That’s just because that fit the data pretty nicely, 00:38:48.190 --> 00:38:52.269 and it seemed that that was mighty stiff compared to everything else. 00:38:52.269 --> 00:38:57.489 So we’re going to try to categorize the materials this way. Next. 00:38:57.489 --> 00:39:01.099 So here is where the 2,200 feet per second came from. 00:39:01.099 --> 00:39:04.749 So there’s the boundary. And that’s the data that fits in there. 00:39:04.749 --> 00:39:08.119 This is the COV on that data. Because you’re not mixing data. 00:39:08.120 --> 00:39:11.420 When you get a big COV, you’re mixing rock and soil. 00:39:11.420 --> 00:39:14.769 That’s where it’s coming from. So here we are. 00:39:14.769 --> 00:39:18.549 We’ve got a reasonable number. This is quite low. 00:39:18.549 --> 00:39:23.660 This just shows you where it’s coming from. Okay, no problem. Next. 00:39:24.100 --> 00:39:32.900 Now, all of this fit right around, you know, what looks like – well, sorry. 00:39:32.900 --> 00:39:34.920 Because the dense gravel isn’t in there. 00:39:34.920 --> 00:39:39.820 It’s just above – it’s above – the dense gravel fits in there like this. 00:39:40.620 --> 00:39:45.480 And so if you look at that, you’ve got a low COV again, shows you where it’s 00:39:45.480 --> 00:39:50.580 coming from. Here’s 100 feet, just to keep in mind. There’s our 30 meters. 00:39:50.580 --> 00:39:57.040 So yes, that’s weathered basalt as far as I’m concerned. Next. 00:39:58.200 --> 00:40:00.440 Here’s the dense gravel. 00:40:00.440 --> 00:40:05.039 I just don’t understand why the line’s not there, but it’s right – 00:40:05.039 --> 00:40:09.499 that yellow line, that median, is just about on top of the dense gravel. 00:40:09.499 --> 00:40:12.279 And, you know, here’s the dense sand. 00:40:12.280 --> 00:40:18.740 So that’s’ stiff soil – okay, what’s the fourth category? There isn’t. Go. 00:40:18.880 --> 00:40:22.580 There’s no fourth category. Because we got nothing that soft. 00:40:22.589 --> 00:40:26.940 So there’s – everything is stiffer than dense sand on the island there that 00:40:26.940 --> 00:40:34.040 we tested. So if you take a look at this, this is a fire station. This is Mac Farms. 00:40:34.040 --> 00:40:38.440 And we could – we’ll take a look at these, and we’ll classify – we haven’t 00:40:38.450 --> 00:40:43.150 drilled there, but we’ll classify the geotechnical deposits. 00:40:43.150 --> 00:40:50.420 Next. So here we are. This is the fire station that was on the right-hand side. 00:40:51.750 --> 00:40:54.100 And that’s the shear wave velocity profile. 00:40:54.119 --> 00:40:57.279 And based on that profile – that shear wave velocity profile – and what I 00:40:57.280 --> 00:41:02.880 showed you with the categories, it’s got stiff soil, weathered basalt and basalt. 00:41:02.880 --> 00:41:06.340 That would be – I’d be willing to put a little money on that, 00:41:06.360 --> 00:41:10.460 depending on, you know, what my odds were. 00:41:10.460 --> 00:41:17.700 And then, on – over here on Mac Farms, on the east – the southeast side of the 00:41:17.700 --> 00:41:22.600 island, you have stiff soil over basalt, and it’s much deeper. 00:41:22.609 --> 00:41:27.359 So this happens to be a site class C. That happens to be a site class D. 00:41:27.360 --> 00:41:33.760 And all of the site class B’s on the 20 stations that we looked at 00:41:33.760 --> 00:41:37.499 turned out to be C’s and D’s. 00:41:37.499 --> 00:41:40.690 So it was – it was very important to make those measurements to 00:41:40.690 --> 00:41:43.829 know how they were responding. Next. 00:41:43.829 --> 00:41:48.190 I hope we see the mountain. Okay, here’s Yucca Mountain. 00:41:48.190 --> 00:41:51.130 And that’s a Liquidator on the top of Yucca Mountain. 00:41:51.130 --> 00:41:54.109 That’s Cecil Hoffpauir. And in fact, when we were working 00:41:54.109 --> 00:41:56.430 on the top of [chuckles] Yucca Mountain, it was the first time 00:41:56.430 --> 00:42:02.540 we had Liquidator out in the field, so we had just built it and stuff. 00:42:02.540 --> 00:42:08.220 And Cecil would go walking around it, and there were bolt heads on the ground. 00:42:08.220 --> 00:42:10.500 This is not a good sign. 00:42:10.500 --> 00:42:14.220 Things were not working well, and we were blowing the top off of it. 00:42:14.220 --> 00:42:18.880 But it was okay. We were given time to fix it. 00:42:18.880 --> 00:42:21.849 But, you know, the other thing that happened on Yucca Mountain – 00:42:21.849 --> 00:42:25.170 this is very non-engineering. You know, you have to bring it back 00:42:25.170 --> 00:42:28.240 to base camp so that you didn’t pollute the area. 00:42:28.240 --> 00:42:31.360 And at night, we would leave, and we’d come back 00:42:31.360 --> 00:42:35.960 the next morning, and woo! It was shiny new. 00:42:38.160 --> 00:42:43.880 Because all the cooking oil that we had to use was licked off by the coyotes. 00:42:43.880 --> 00:42:46.720 Oh, yeah. I am not kidding. I mean, they made it spotless. 00:42:46.729 --> 00:42:50.779 And we smelled like french fries when we got down to the site. 00:42:50.779 --> 00:42:54.519 They were following us. [chuckles] That was a little disturbing. 00:42:54.520 --> 00:42:58.160 Are you telling me – are we back? - Trying to fix it. 00:43:00.240 --> 00:43:05.400 - But they can’t stay here that long, so that’s – let’s … 00:43:06.320 --> 00:43:11.460 [Silence] 00:43:12.440 --> 00:43:15.390 Can you go back about 20 slides? And I’m only going to put one, 00:43:15.390 --> 00:43:17.819 two, three, that we go through. But I need to see them. 00:43:17.820 --> 00:43:20.460 Oh, good, good, good. Okay. Okay. 00:43:20.460 --> 00:43:24.700 There’s the shear wave velocity of the dam – the alluvium that I said. 00:43:24.700 --> 00:43:28.059 And all we did – we plotted vertical effective stress. 00:43:28.060 --> 00:43:31.760 That’s the velocity. That’s – don’t worry if that’s missing. 00:43:31.760 --> 00:43:36.099 And you see the sites. And that equation tells you it’s 00:43:36.099 --> 00:43:39.400 not cemented. Because if it was cemented, that’d be way up there. 00:43:39.400 --> 00:43:43.690 And that exponent tells you that it’s not cemented because it’ll be 00:43:43.690 --> 00:43:47.880 much flatter if it’s cemented. You can identify that for the material. Next. 00:43:47.880 --> 00:43:51.230 Remember how I told you, if you got a vertical line when you had 00:43:51.230 --> 00:43:54.829 the right equation that that tells you it’s all uniform material? 00:43:54.829 --> 00:43:58.960 You can use that as a – as a characteristic of figuring out what’s there. 00:43:58.960 --> 00:44:03.749 You already know that it won’t liquefy. Okay, keep going. Keep going. 00:44:03.749 --> 00:44:05.200 Keep going. 00:44:05.200 --> 00:44:08.300 Woo! Beautiful data. Okay. 00:44:08.310 --> 00:44:10.229 So here – we’ll just look at this one. 00:44:10.229 --> 00:44:13.840 Here we are. They’re up 25 feet. We did SASW. 00:44:13.840 --> 00:44:16.969 Here, they’re up another 25 feet. We did SASW. 00:44:16.969 --> 00:44:22.289 So this point moved from here to here. Why? Because of confining pressure. 00:44:22.289 --> 00:44:24.630 You added more material on top. 00:44:24.630 --> 00:44:26.700 Then we go up here. Now we can’t – we don’t have 00:44:26.700 --> 00:44:29.460 as many here because the nuclear island is right there. 00:44:29.460 --> 00:44:33.329 So we can’t go across – we were going across where the nuclear island was. 00:44:33.329 --> 00:44:35.759 Now they’re building it up, so we can’t go across there. 00:44:35.760 --> 00:44:37.979 Here we are. Here we are. Next. 00:44:38.360 --> 00:44:42.180 Okay, there’s the COV I told you about – 0.04 to 0.05. 00:44:42.180 --> 00:44:45.489 That’s what it looks like. That’s all the sites. Next. 00:44:45.489 --> 00:44:49.369 Here is the vertical line. So if you got a good equation for it, 00:44:49.369 --> 00:44:52.960 and you want Vs-1, it’s just – all it is is that number – 00:44:52.960 --> 00:44:57.800 well, that number, but if you had Vs as equal to Vs-1 times this equation, it’d be 00:44:57.800 --> 00:45:03.960 sigma over P-sub-a. You got it. And so you say, I have a uniform material. Next. 00:45:03.960 --> 00:45:06.940 This I wanted to discuss with you. So thank you. 00:45:06.940 --> 00:45:08.579 Who do I thank? - [inaudible] 00:45:08.579 --> 00:45:13.010 - The guy with two Ph.D.s? Perfect. Thank you. 00:45:13.010 --> 00:45:17.640 So let’s just take this shear wave velocity profile, 00:45:17.640 --> 00:45:21.130 and we’re going to convert it into a laboratory test. 00:45:21.130 --> 00:45:23.710 So we’re going to say, here we have confining pressure. 00:45:23.710 --> 00:45:26.719 That’s plotted right there. It’s mean effective confining pressure, 00:45:26.719 --> 00:45:29.390 and we tell you everything we’re doing. There’s K-naught of a 1/2. 00:45:29.390 --> 00:45:35.819 So all the stuff’s on the – on the plots. And you put that – so that’s from the 00:45:35.820 --> 00:45:41.780 way you’re using uniform layers in your SASW analysis in your modeling. 00:45:41.780 --> 00:45:43.640 And you put a line through it. 00:45:43.640 --> 00:45:48.539 Now, you come and you do lab tests. This is just a few of them. 00:45:48.539 --> 00:45:52.450 I should have asked a question before I showed you. 00:45:52.450 --> 00:45:55.060 Is the lab more uniform than the field? 00:45:55.060 --> 00:45:57.840 No. Why? 00:46:00.240 --> 00:46:04.819 Because the lab samples are this big, and the field samples are that big. 00:46:04.819 --> 00:46:09.549 It’s because you have more variability with little, bitty samples, even from what 00:46:09.549 --> 00:46:14.469 looks like a fairly uniform material when you’re testing them at such small ones. 00:46:14.469 --> 00:46:17.950 So here’s – that’s the lab, all the gray, and that’s the field. 00:46:17.950 --> 00:46:21.450 By the way, I should tell you. When we had to testify before the 00:46:21.450 --> 00:46:24.769 Nuclear Regulatory Commission, they asked me that question. 00:46:24.769 --> 00:46:28.740 And I screwed up. I didn’t answer it correctly. 00:46:28.740 --> 00:46:32.079 And I said, what the heck did I say? And, you know, then they went on, 00:46:32.079 --> 00:46:33.410 and they had – they were talking. 00:46:33.410 --> 00:46:35.989 I was still able to sit up at the table where they’re asking questions. 00:46:35.989 --> 00:46:38.619 They are talking to some other people, asking them questions. 00:46:38.619 --> 00:46:42.010 And then I raised my hand. I’m a faculty member. 00:46:42.010 --> 00:46:44.099 I can raise my hand too, just like a student. 00:46:44.100 --> 00:46:47.760 I said, I answered the question incorrectly. Can I do it again? 00:46:47.760 --> 00:46:51.520 [chuckles] Okay. And came up with what I just told you. 00:46:51.520 --> 00:46:56.980 But it’s just very interesting to see how these things fit together. Next. 00:46:56.980 --> 00:47:00.869 That’s the best data you can get, and they don’t fit together perfectly. 00:47:00.869 --> 00:47:04.569 Okay, and I told you the base of the island, it was above 1,000 feet. 00:47:04.569 --> 00:47:07.609 You know, you get this from time to time. 00:47:07.609 --> 00:47:12.789 Even on Dillon Dam when – I got to be careful how I say this now. 00:47:12.789 --> 00:47:17.510 My sensitivity has to kick in. You know, when the contractor or 00:47:17.510 --> 00:47:21.190 somebody might want to come up and give you a kiss because they’re so happy. 00:47:21.190 --> 00:47:25.140 And I’m saying, wait, wait, wait. That’s just reserved for my wife. 00:47:25.140 --> 00:47:28.360 You know, they were delighted. 00:47:28.360 --> 00:47:33.700 Because this was $100 million problem right there. Next. 00:47:34.380 --> 00:47:35.900 Keep going. 00:47:36.140 --> 00:47:39.720 Keep on a-chargin’. We got all – oh, back – back one. 00:47:39.730 --> 00:47:42.469 A couple. There. There’s the – there’s the dense gravel. 00:47:42.469 --> 00:47:45.339 There’s the sand. That’s what we couldn’t see. 00:47:45.340 --> 00:47:49.140 I’m happy you’ll have a good set of slides. Next. 00:47:50.209 --> 00:47:53.300 Next. So there’s Liquidator down there. 00:47:53.309 --> 00:47:55.140 We haven’t got the total station up yet, 00:47:55.140 --> 00:47:58.320 but in the end, you won’t even see where it is. Next. 00:47:59.120 --> 00:48:02.400 And we’re testing here on the mountain. We’ve tested over here as well – 00:48:02.410 --> 00:48:05.829 [inaudible] ridge and so forth. And we’ll show you what some 00:48:05.829 --> 00:48:08.440 things look like. And we’ll also compare them with the mountain. 00:48:08.440 --> 00:48:13.599 And by the way, we did some over in this area. It’s not showing so well. Next. 00:48:13.599 --> 00:48:17.660 And this just shows you all the data is from 19 sites around there 00:48:17.660 --> 00:48:21.140 from the surface. And I think you can see right away, 00:48:21.140 --> 00:48:26.049 okay, it looks like some come out here, and some come out there, doesn’t it? 00:48:26.049 --> 00:48:28.959 Okay, but here’s the COV when you start mixing. 00:48:28.959 --> 00:48:34.559 And you – this is really typical of what you find when you get a lot of data 00:48:34.559 --> 00:48:38.489 like you can collect for a reasonable amount with surface waves. 00:48:38.489 --> 00:48:42.910 And that is that this COV does jump up a lot here. Why? 00:48:42.910 --> 00:48:46.580 Because there’s a stiff layer here and not there. 00:48:47.240 --> 00:48:49.140 And that’s a fact. 00:48:49.140 --> 00:48:52.380 And so, if you’re looking at stuff on top of the mountain, 00:48:52.390 --> 00:48:55.799 well, you’re going to design it differently than here than there. 00:48:55.800 --> 00:49:00.800 But that’s going to go down when you divide these profiles of 19 into two pots. 00:49:00.800 --> 00:49:05.819 Next. So here’s the stiffer one where that layer comes in. 00:49:05.819 --> 00:49:08.109 And you see now it’s still about 0.2. 00:49:08.109 --> 00:49:12.890 But, again, that 0.2 arises because of those layer boundaries 00:49:12.890 --> 00:49:15.420 varying around there. 00:49:15.420 --> 00:49:20.049 And some of that variation could be, we just used where we were, 00:49:20.049 --> 00:49:24.079 and I don’t think – I forget if we put leveling in there or if we even – 00:49:24.080 --> 00:49:29.210 I don’t think we had the data. But at any rate, that’s the stiff side. Next. 00:49:29.820 --> 00:49:33.080 Oh. [chuckles] And so we did some testing in the tunnel. 00:49:33.080 --> 00:49:38.920 Oh, we did a lot of testing in the tunnel – surface wave testing. Next. 00:49:38.920 --> 00:49:46.219 And there’s the tuffs in that group that were at that elevation in the tunnel. 00:49:46.219 --> 00:49:48.930 And we were seeing them from the surface. Next. 00:49:48.930 --> 00:49:52.430 That’s a repository – here’s the other one. 00:49:52.430 --> 00:49:54.420 And you’ll see differences around there, 00:49:54.420 --> 00:49:56.599 but only when you put all the data together. 00:49:56.599 --> 00:50:01.759 Because if you didn’t put all the data together, what does that mean? 00:50:01.760 --> 00:50:05.180 You didn’t have a big budget. Oh, my goodness. 00:50:06.269 --> 00:50:08.160 Yucca Mountain? 00:50:08.160 --> 00:50:10.969 The only thing – oh, this is being recorded. 00:50:10.969 --> 00:50:13.340 I’m not going to say anything more. 00:50:14.540 --> 00:50:19.200 Okay. I’d love to say something more, but it’s political. 00:50:19.200 --> 00:50:21.200 Okay, next. 00:50:22.120 --> 00:50:26.200 Now, sometimes we’d like to look at lateral variability. 00:50:26.200 --> 00:50:32.680 And we will add a geophone here. And if you really knew the truth, okay, 00:50:32.680 --> 00:50:36.579 those darn MASW guys, they got a whole bunch of geophones out there. 00:50:36.579 --> 00:50:39.589 I’ll put another one out there too. 00:50:39.589 --> 00:50:46.339 And so this X, that X, and that X can all be compared together. Next. 00:50:46.340 --> 00:50:49.060 And it gives you a sense for lateral variability. 00:50:49.920 --> 00:50:51.880 What the heck’s that? 00:50:53.280 --> 00:50:55.120 Kottke, you did that. 00:50:55.130 --> 00:50:59.529 Okay, so here are some – this is in west Texas. 00:50:59.529 --> 00:51:02.900 I have never seen this before in my life. Next. 00:51:02.900 --> 00:51:08.180 And I’m blaming it on whosever computer – holy crimonilly. 00:51:09.160 --> 00:51:15.280 Okay, this is a beautiful, beautiful slide. I’m telling you it’s – remember, 00:51:15.289 --> 00:51:17.420 I showed you the one with all the different colors? 00:51:17.420 --> 00:51:20.410 Now, here’s lateral variability, and there it is. 00:51:20.410 --> 00:51:23.039 And they are right on top of each other. 00:51:23.040 --> 00:51:26.380 You can’t check me, can you? Okay, next. 00:51:26.380 --> 00:51:28.980 Oh, there they are. Okay. 00:51:29.000 --> 00:51:34.440 I don’t know – I got to do the best I can not to swear. 00:51:35.180 --> 00:51:38.280 Oh, my goodness gracious sakes alive. 00:51:40.580 --> 00:51:48.920 You know, maybe this is a sign that I should retire. Huh? Holy crimonilly. 00:51:48.920 --> 00:51:51.980 Okay, this is good. I still can get away with it here. 00:51:51.980 --> 00:51:54.079 Remember, I told you, there’s lateral variability. 00:51:54.079 --> 00:51:57.009 There’s lateral variability. There’s lateral variability. 00:51:57.009 --> 00:52:00.019 See how all those points are on top of each other? 00:52:00.019 --> 00:52:05.299 This just shows, when we do this – when we go to model that curve, 00:52:05.300 --> 00:52:11.360 we will then take that curve, and we will show it – we will show it as [chuckles] – 00:52:11.360 --> 00:52:14.059 you know, Alicia had to shut down her computer because we were 00:52:14.060 --> 00:52:18.540 having trouble with it. And I just have figured out where the trouble was. 00:52:18.540 --> 00:52:23.100 I mean, I’m seeing this screwed-up thing. 00:52:23.100 --> 00:52:28.560 So when I go back to Texas – because I’m not packing right now – 00:52:28.560 --> 00:52:31.410 I’m going to have to take out my gun and shoot the computer. 00:52:31.410 --> 00:52:34.609 Haven’t we seen that on YouTube or something? Okay. 00:52:34.609 --> 00:52:38.220 Well, I won’t do that. But I sure am frustrated. 00:52:38.220 --> 00:52:43.289 But what you see is, we would – we would show – that’s meant to 00:52:43.289 --> 00:52:46.799 show you, on an arithmetic scale – so that’s quite vertical. 00:52:46.800 --> 00:52:49.600 And that’s the long wavelength. That’s the short wavelength. 00:52:49.600 --> 00:52:52.660 Over here, we’d have the long wavelengths, and we can 00:52:52.660 --> 00:52:56.250 see how the things fit together. And here is the profile. 00:52:56.250 --> 00:52:59.200 Don’t ask me how it’s offset. 00:52:59.200 --> 00:53:04.239 When I go back, I’m going to put it on the computer, and if it’s perfect, 00:53:04.240 --> 00:53:10.220 I’m sending out a nasty note to USGS. Who do I write? You? 00:53:10.220 --> 00:53:11.560 - Not me. - Yeah. It’s not going to 00:53:11.560 --> 00:53:13.289 do any good, is it? [laughter] 00:53:13.289 --> 00:53:18.359 Okay. I’m sorry. I worked so hard on this for you. Dang it. 00:53:18.359 --> 00:53:21.880 Okay. Please let this one come through. 00:53:21.880 --> 00:53:25.640 Okay, here’s the Greenfield site in Georgia. 00:53:25.640 --> 00:53:31.869 And it’s Southern Company again. And two new nuclear power plants 00:53:31.869 --> 00:53:35.880 were proposed for this location. It’s on hold right now. 00:53:35.880 --> 00:53:40.120 But we’ve got – so we have some deep SASW profiling. 00:53:40.130 --> 00:53:43.459 And you didn’t see in the slides – I would tell you that moderate depth, 00:53:43.460 --> 00:53:47.760 now, to us – this is new, I mean, in the last four years or so. 00:53:47.760 --> 00:53:51.540 Moderate depth means more than 150 meters. 00:53:51.540 --> 00:53:55.880 Deep means more than 300 meters. Very deep is what’s supposed to be 00:53:55.890 --> 00:54:01.190 shown here – please, please, please – is 600 meters or more. Okay? 00:54:01.190 --> 00:54:02.559 And so that’s what we’re doing. 00:54:02.559 --> 00:54:06.519 The only line that will have 600 meters is along here. 00:54:06.519 --> 00:54:11.499 And they built a concrete pad for us to put Liquidator on. 00:54:11.499 --> 00:54:13.950 And this is a way we could do it. Next. 00:54:13.950 --> 00:54:17.599 So here’s Liquidator – and thank goodness I didn’t have – I have a 00:54:17.599 --> 00:54:21.900 video of this, and I didn’t put it in here. But here’s Liquidator. 00:54:21.900 --> 00:54:27.210 And now it’s on a bigger drum. I would like it even bigger. 00:54:27.210 --> 00:54:33.040 The base plate that vibrates is put down on the pad, and it’s not vibrating. 00:54:33.040 --> 00:54:37.339 Everything in the white and the wheels is going up and down. 00:54:37.339 --> 00:54:42.400 It took me four, five years to be so frustrated with this that I finally told 00:54:42.400 --> 00:54:47.819 them, that’s it. We’re going to lift the whole machine up and see what happens. 00:54:47.819 --> 00:54:53.029 And so this – Liquidator is very good because it goes to full force, 00:54:53.029 --> 00:54:57.190 which is not typical of a really big vibe. But it goes to full force down here 00:54:57.190 --> 00:55:01.420 to 1.3 hertz. And we can go down to 1 hertz and still get good stuff. 00:55:01.420 --> 00:55:05.359 Now we were out here at about 0.6 and above. 00:55:05.359 --> 00:55:09.980 And it’s always step-sweeping – it’s shown on the advertisement, 00:55:09.980 --> 00:55:14.960 but – and I didn’t show you here. Well, I had it, but I didn’t show you. 00:55:14.960 --> 00:55:19.960 But that – right there, that more than doubles your depth. 00:55:20.720 --> 00:55:24.920 I mean, every time you can change a frequency by a factor of 2, 00:55:24.930 --> 00:55:28.160 you have doubled your depth or more because it’s getting stiffer, 00:55:28.160 --> 00:55:33.620 so you’re getting even higher velocities to go along with that frequency. Next. 00:55:34.540 --> 00:55:36.280 [laughs] 00:55:38.660 --> 00:55:40.579 Well, you almost have it. 00:55:40.579 --> 00:55:43.579 So here we are. That goes up there. 00:55:43.579 --> 00:55:46.859 Here we are. Here are the shear wave velocities. 00:55:46.860 --> 00:55:52.140 That’s down to 300 meters. That’s more right in here – 350 meters. 00:55:52.140 --> 00:55:56.140 That’s all five of them. Then I showed you that red one, 00:55:56.150 --> 00:56:00.940 that one right there – and I guess it’s green, excuse me, here. 00:56:00.940 --> 00:56:05.519 But that’s gone down to – oh, my gosh. 00:56:05.519 --> 00:56:06.740 Go to the next one. 00:56:06.740 --> 00:56:10.809 And that’s the only slide we have. Damn it. Backwards. 00:56:10.809 --> 00:56:17.309 Okay, that goes down to 620 meters, 630 meters solid. 00:56:17.309 --> 00:56:20.699 And then we used near-field to continue it down to about 800. 00:56:20.699 --> 00:56:25.079 And so you can get after us for that, but that velocity right there 00:56:25.079 --> 00:56:29.049 is about 3,000 meters per second – a little bit above. 00:56:29.049 --> 00:56:34.980 And here’s a suspension log out here, close – getting close to 4,000. 00:56:35.740 --> 00:56:40.060 I’m not going to say anything more than that. We feel really good about this. 00:56:40.069 --> 00:56:42.930 That was still a solid line. Once we go to near-field, 00:56:42.930 --> 00:56:47.420 we’ll show you a dashed line. We won’t try to mislead you. Next. 00:56:50.160 --> 00:56:53.240 Okay, this was a fly-in as well. 00:56:54.380 --> 00:56:58.280 I will never be invited back. I can see that right now. [laughter] 00:56:58.280 --> 00:57:02.860 Wow. So I was going to ask you – here was your quiz. [chuckles] 00:57:02.869 --> 00:57:07.589 Your quiz was, okay, here’s a lab curve for soil. 00:57:07.589 --> 00:57:10.560 This is La Cienaga – Northridge earthquake. 00:57:10.560 --> 00:57:13.749 Down at 20 – sorry, down at 185 meters. 00:57:13.749 --> 00:57:17.569 It was a silty sand. It was a pitcher barrel sampler. 00:57:17.569 --> 00:57:20.359 We confined it to what we think is a reasonable estimate for the 00:57:20.359 --> 00:57:23.229 in situ state of stress, and there’s the lab curve. So my question was 00:57:23.229 --> 00:57:26.519 going to be, what does the field shear wave velocity show you? 00:57:26.519 --> 00:57:30.019 Well, you can see, huh? Yeah, here it is. 00:57:30.020 --> 00:57:34.360 This is in modulus. So this is a factor of 2, huh? 00:57:34.360 --> 00:57:38.620 750, 1,500 – close enough. We don’t care what the units are. 00:57:38.630 --> 00:57:42.720 Okay, so you got a factor of 2. Then you’re going to – 00:57:42.720 --> 00:57:47.430 the seismologists are going to take that lab curve, multiply by 2, 00:57:47.430 --> 00:57:51.029 and that’s the design curve in the equation, looking in the response – 00:57:51.029 --> 00:57:54.160 earthquake response, okay? That’s what’s done. 00:57:54.160 --> 00:57:59.749 So we’ll make this quiz easier now for me to ask. 00:57:59.749 --> 00:58:03.160 What is this graph going to look like when you have rock? 00:58:04.520 --> 00:58:07.680 You can’t answer it because you’ve seen it in class. 00:58:10.540 --> 00:58:16.120 Well – and Yucca Mountain is a good example of this 00:58:16.130 --> 00:58:17.719 because they had lots of core. 00:58:17.720 --> 00:58:24.620 So I would be at the core – not shed, but the core facility, huh? 00:58:24.620 --> 00:58:28.940 And they’d have it spread out, and I’d be looking at all these boxes, 00:58:28.950 --> 00:58:31.809 and I’m going, well, we can’t test that. That’s – oh, we can’t test that. 00:58:31.809 --> 00:58:33.799 That’s fractured. Oh, here’s a good piece. 00:58:33.800 --> 00:58:37.520 We’ll take that one. And, you know, it is so biased. 00:58:37.520 --> 00:58:43.680 It’s more than soil. It’s worse than soil in bias. Next. 00:58:43.680 --> 00:58:47.339 So here’s a lab curve. And this is going to be 00:58:47.339 --> 00:58:51.249 bigger and lower, huh, in the field, generally speaking. 00:58:51.249 --> 00:58:55.360 Now, it all depends on the fracturing and the material, huh? 00:58:55.360 --> 00:59:00.380 Next. So, hallelujah. If you don’t get anything more 00:59:00.390 --> 00:59:05.339 from the talk than this, it might be okay. But this is typical soil. 00:59:05.339 --> 00:59:12.200 This is all our data. So I’m – I don’t know if it’s – 00:59:12.200 --> 00:59:17.769 I like to keep careful control over data. So all of this lab data, we did. 00:59:17.769 --> 00:59:20.279 So if there’s something wrong, it’s something we’ve done, 00:59:20.279 --> 00:59:23.539 and it’s consistently through here on both of these. 00:59:23.539 --> 00:59:27.009 And so what you see – we found the best relationships 00:59:27.009 --> 00:59:31.969 are determined knowing the field shear wave velocity – this is soil. 00:59:31.969 --> 00:59:36.860 The field shear wave velocity where these samples were taken. This is rock. 00:59:36.860 --> 00:59:41.740 And this ratio is a – shear wave velocity measured in the lab divided by 00:59:41.750 --> 00:59:46.459 the shear wave velocity in the field. So we had to try to duplicate the field 00:59:46.459 --> 00:59:50.890 conditions, and there could be some inconsistencies there. 00:59:50.890 --> 00:59:54.510 But what you see is, when the soil is real soft, 00:59:54.510 --> 00:59:58.460 you don’t – you almost can’t disturb it because it’s so soft, huh? 00:59:58.460 --> 01:00:02.579 That’s 100 meters per second or 150 meters per second, huh? 01:00:02.579 --> 01:00:07.819 And as it gets stiffer, out here to 800 meters per second, 01:00:07.819 --> 01:00:11.800 the shear wave velocity changes by, let’s say, 2. 01:00:11.800 --> 01:00:15.829 So that means the modulus changes by 4. Okay? 01:00:15.829 --> 01:00:20.380 So this has got a factor of 4 in modulus. Here we are in rock. 01:00:20.380 --> 01:00:28.080 So now, the rock that’s the stiffest, typically, has an RQD of 100%. 01:00:28.080 --> 01:00:32.680 In fact, you might get 5-foot – you core 5 feet, you get a 5-foot sample back. 01:00:32.690 --> 01:00:36.499 And we’ve seen that. And this is – I just don’t have the data, but we have 01:00:36.500 --> 01:00:43.260 data right there, is from a top secret site. So it’s not supposed to be there. 01:00:43.260 --> 01:00:48.200 And that’s not a joke. And, as we move along here, you know, 01:00:48.210 --> 01:00:52.890 you see that, when we’re down to about 800 – so this is cored samples. 01:00:52.890 --> 01:00:58.839 These are pitcher barrel samples. So push tube is a little too simple. 01:00:58.839 --> 01:01:04.290 But now you see a factor of 4. That means the modulus change is 16. 01:01:04.290 --> 01:01:09.289 It’s twice as bad – or you can get into – well, 4 times – sorry. 01:01:09.289 --> 01:01:14.480 You can get into a huge difference. But I think the geologists know this. 01:01:14.480 --> 01:01:17.109 I’m just speaking as a geotechnical engineer, 01:01:17.109 --> 01:01:22.680 and it took me a long time to figure that out, or to get a handle on that. Next. 01:01:25.060 --> 01:01:29.420 First conclusion is, I apologize for the screw-up in the slides. 01:01:29.420 --> 01:01:33.520 I have no idea. But I’ll get you a good set of slides. 01:01:34.700 --> 01:01:37.540 But active-source surface wave measurements – 01:01:37.549 --> 01:01:40.579 so they aren’t passive – active-source – have been used 01:01:40.580 --> 01:01:46.860 for more than 25 years and been working well, I think. 01:01:47.700 --> 01:01:50.779 The measurement method is theoretically sound. 01:01:50.779 --> 01:01:53.640 Will continue to be improved. I think that’s a big deal. 01:01:53.640 --> 01:01:59.289 I’ve always said that to students in class. Because there’s a future for that. 01:01:59.289 --> 01:02:01.369 And it’s going to be applied in even more applications. 01:02:01.369 --> 01:02:05.239 And I didn’t show you – I mean, I can show you all kinds of 01:02:05.239 --> 01:02:08.859 applications that have nothing to do with geology. 01:02:08.859 --> 01:02:15.800 V-sub-s profiling ranges from, for us, 3 centimeters or 01:02:15.800 --> 01:02:21.181 something like that to 600 meters. Passive-source surface wave 01:02:21.181 --> 01:02:27.219 measurements are increasing in people applying them that are 01:02:27.219 --> 01:02:31.970 very good and increasing in their number of applications. 01:02:31.970 --> 01:02:37.480 And I think they have even more opportunity because they’re cheaper. 01:02:38.200 --> 01:02:39.960 Big sources are expensive. 01:02:39.960 --> 01:02:44.220 I think you’re going to see those used more in the future. 01:02:44.940 --> 01:02:48.239 This is important to me. We participated in numerous blind 01:02:48.239 --> 01:02:53.410 comparisons over the past 30 years. And, as far as I’m concerned, 01:02:53.410 --> 01:02:58.220 our reputation is still intact. We’re not going to put that up to a vote. 01:02:58.220 --> 01:02:59.780 Next. 01:02:59.780 --> 01:03:02.580 I won’t read this. Don’t worry. Well, I can’t. 01:03:02.580 --> 01:03:06.680 Let me just say that there have been all kinds of people who have 01:03:06.680 --> 01:03:11.069 worked on this, and the most important thing down here that I need to say is, 01:03:11.069 --> 01:03:13.549 we really appreciate the National Science Foundation 01:03:13.549 --> 01:03:16.740 [chuckles] which is down here written. 01:03:16.740 --> 01:03:23.539 And that they were – well, let me say it two ways, because it’s here. 01:03:23.539 --> 01:03:25.970 We appreciate the National Science Foundation, 01:03:25.970 --> 01:03:30.600 and we appreciate some open-minded reviewers. 01:03:31.600 --> 01:03:34.160 Which doesn’t always happen. 01:03:35.209 --> 01:03:37.720 That thought those big machines were good. 01:03:37.729 --> 01:03:40.859 And so, without the National Science Foundation and those good reviewers, 01:03:40.859 --> 01:03:45.289 who I don’t know who they are today, but thank you very much, reviewers, 01:03:45.289 --> 01:03:47.939 for helping us get started with this big equipment. 01:03:47.940 --> 01:03:55.060 And just for the record – I can say this on tape – I have four grandchildren. 01:03:56.600 --> 01:04:03.299 They are all driving cars or above – some have – one has – two have 01:04:03.300 --> 01:04:08.360 graduated from college. But when they were little kids, they all rode in T-rex. 01:04:08.360 --> 01:04:11.619 And, boy, that’s a big deal for a grandpa, you know? 01:04:11.620 --> 01:04:14.320 Because, woo, woo, that was hot stuff. [laughter] 01:04:14.320 --> 01:04:19.960 Okay, that’s my talk. I’m sorry about the slides. 01:04:20.900 --> 01:04:26.220 This has ruined my year. In fact, it’s ruined my next 10 years. 01:04:26.220 --> 01:04:29.880 I’ve never had that happen before. Excuse me. 01:04:30.340 --> 01:04:36.220 [Applause] 01:04:36.220 --> 01:04:38.439 - Thanks, Ken. So if anyone has questions or 01:04:38.439 --> 01:04:41.699 IT support for Ken, feel free to jump in. - Yeah, by the way, so my reputation 01:04:41.700 --> 01:04:45.000 is now ruined, huh, because this is going to live forever. 01:04:45.900 --> 01:04:48.520 - Hey, Ken. So in your conclusion, 01:04:48.529 --> 01:04:54.910 you mentioned that there is a big future for surface-based methods in 01:04:54.910 --> 01:05:01.099 terms of active and passive source. So, I mean, sky’s the limit, right? 01:05:01.099 --> 01:05:05.170 But what do you think are the top three impediments that 01:05:05.170 --> 01:05:10.500 we’re currently facing for these sorts of surface-based methods? 01:05:11.260 --> 01:05:13.920 - Wow. That’s a good question. 01:05:15.800 --> 01:05:21.140 [Silence] 01:05:21.140 --> 01:05:28.380 Probably the numerical modeling. I mean, getting the numerical modeling 01:05:28.380 --> 01:05:32.829 to be able to go even with the passive methods – you know, okay, 01:05:32.829 --> 01:05:37.140 I got a huge circle, I have a moderate circle, I have a little circle. 01:05:37.140 --> 01:05:40.309 Well, wait a minute. There’s all kinds of stuff out there. 01:05:40.309 --> 01:05:43.869 So it depends on what you’re looking for. 01:05:43.869 --> 01:05:49.680 Hence, the numerical modeling, if they’re going to be still average 01:05:49.680 --> 01:05:56.720 properties or if you need to find more detail in the – in the systems, and that, 01:05:56.720 --> 01:06:02.689 to me, is numerical modeling as much as anything. I don’t do any of that. 01:06:02.689 --> 01:06:06.450 But I think that – I think that’s the biggest impediment. 01:06:06.450 --> 01:06:10.790 And when you start doing that, though, if you do that active-source – 01:06:10.790 --> 01:06:14.809 which, maybe that’s what has to be done, and passive won’t do it – 01:06:14.809 --> 01:06:20.099 I don’t know – for three-dimensional measurements, 01:06:20.099 --> 01:06:25.759 is the cost and the time that takes, really, to get that. 01:06:25.759 --> 01:06:29.479 You know, in the shallow, where some of us work also – 01:06:29.479 --> 01:06:32.609 in the shallow environment – and the shallow environment, to me, 01:06:32.609 --> 01:06:40.779 is even 10 meters, three-dimensional profiling is getting to be a big deal 01:06:40.779 --> 01:06:44.700 in liquefaction analyses and trying to understand it. 01:06:44.700 --> 01:06:49.890 Well, that’s still a very difficult situation. Because when you do that, 01:06:49.890 --> 01:06:53.559 you’re getting in the situation where you might have Poisson’s ratio 01:06:53.559 --> 01:07:00.079 nearly 0.4992, and your modeling starts to blow up on you. 01:07:00.079 --> 01:07:06.499 So there are – since I don’t know enough about it, to me, 01:07:06.500 --> 01:07:11.679 that’s probably the biggest thing. I didn’t give you three. 01:07:13.220 --> 01:07:16.960 - Could we look at your conclusion slide? 01:07:18.840 --> 01:07:22.060 - Maybe. I don’t know if it’s gone now. 01:07:22.060 --> 01:07:27.019 - Okay, so four of the five are not conclusions. 01:07:27.019 --> 01:07:28.859 They’re statements of fact. - Yep. 01:07:28.859 --> 01:07:34.260 - So could you just say one sentence – add one sentence to each of these 01:07:34.260 --> 01:07:36.900 conclusions so I understand what your message – 01:07:36.900 --> 01:07:39.330 because the first one says, active-source surface wave 01:07:39.330 --> 01:07:41.660 measurements have been used for 25 years. 01:07:41.660 --> 01:07:44.579 Am I supposed to conclude, and they’re working great? 01:07:44.579 --> 01:07:48.440 Or that they are – they are – still need development? 01:07:48.440 --> 01:07:49.849 Or they’re not working at all? 01:07:49.849 --> 01:07:53.460 I don’t get the conclusion from these – the first four. 01:07:54.709 --> 01:07:57.860 - Good question. 01:07:57.860 --> 01:08:02.100 And I do have a slide that talks about the profession. 01:08:03.080 --> 01:08:13.259 And I think surface wave measurements, in the wrong hands, are – 01:08:13.260 --> 01:08:16.880 sort of comes out of this, but it’s not said that way. 01:08:16.880 --> 01:08:23.700 Surface wave measurements, in the wrong hands, can be greatly abused. 01:08:23.700 --> 01:08:30.420 And nobody – you can be misled. I mean, the biggest problem is, okay, 01:08:30.420 --> 01:08:35.180 I’ve got some shear wave velocity data. Well, how does that seem? 01:08:35.180 --> 01:08:42.620 Well, a lot of people just want to produce it, maybe get paid or be able to 01:08:42.620 --> 01:08:47.920 publish, and don’t do a good job. And that really misleads the public. 01:08:47.920 --> 01:08:55.080 So for me, the – that’s one of the – one of the – I’m sorry, Alan, 01:08:55.080 --> 01:09:00.880 that’s one of the problems. One of the problems is not having – 01:09:00.880 --> 01:09:06.600 having software out there – I have seen people get – buy software, 01:09:06.609 --> 01:09:10.989 be told – not even be told – know that they could get all the 01:09:10.989 --> 01:09:15.589 money back that they paid for that sort of stuff in one job or two jobs and go 01:09:15.589 --> 01:09:20.109 out and start doing it. And they didn’t know a surface wave if it bit them. 01:09:20.109 --> 01:09:22.339 They had no background and so forth. 01:09:22.339 --> 01:09:26.650 And they were doing – and this still happens today. 01:09:26.650 --> 01:09:28.929 So that would be one of my big conclusions. 01:09:28.929 --> 01:09:35.299 I guess the biggest conclusion I wanted to show you is that 01:09:35.300 --> 01:09:41.500 you can learn a lot about the subsurface from surface wave measurements. 01:09:41.500 --> 01:09:47.940 And there is a big future – in fact, Albert, Alan, and I were talking about it. 01:09:47.949 --> 01:09:53.410 Right now, we’re in – we’re looking at spillways that could erode, huh? 01:09:53.410 --> 01:09:57.130 Whoa. Surface waves are perfect for looking at some of that stuff 01:09:57.130 --> 01:10:01.710 and trying to figure out what’s down there without spending too much money 01:10:01.710 --> 01:10:06.989 to start out with to see if you have to spend a lot more money on the project. 01:10:06.989 --> 01:10:15.179 So they can be used, in many instances, to make sure what you – 01:10:15.179 --> 01:10:21.550 what you were designing, you did get. Or to make sure, if you’ve – 01:10:21.550 --> 01:10:23.940 if things are out there, and you’re worried about them, 01:10:23.940 --> 01:10:25.639 should you be worried about them or not? 01:10:25.640 --> 01:10:28.360 I guess … - Okay. So for number 4, 01:10:28.360 --> 01:10:31.699 passive-source surface wave measurements are increasing in 01:10:31.699 --> 01:10:35.809 their number of applications, but the results should be viewed … 01:10:35.809 --> 01:10:41.610 - No, no, no, no. I don’t want to say that. No, I just am saying that those are 01:10:41.610 --> 01:10:46.940 even – in my mind, even more complex to use than active-source. 01:10:46.940 --> 01:10:49.120 And ... 01:10:52.580 --> 01:10:55.280 the potential is there because ... 01:10:58.320 --> 01:11:00.560 in active-source, I can tell you, 01:11:00.560 --> 01:11:04.560 while we’re out in the field, if things need to be changed. 01:11:04.560 --> 01:11:09.719 If we’re collecting good data or if the complexity of the site is there, 01:11:09.719 --> 01:11:12.909 so that you’ve got a – you have to change something, 01:11:12.909 --> 01:11:15.920 or it’s so complex, you might not be able to do it. 01:11:15.920 --> 01:11:19.340 Which tells you the underground is really a mess. 01:11:21.350 --> 01:11:23.680 I don’t know. Ask me a couple other questions 01:11:23.700 --> 01:11:27.540 that will try to make me think and see if we can get on the right track here. 01:11:29.020 --> 01:11:31.360 - I said enough. I think maybe others have something. 01:11:31.360 --> 01:11:35.120 - No, no. Those were good. That’s very good. Thank you. 01:11:35.520 --> 01:11:40.400 - So if I may add, I think, Ken, you answered – you’ve made good 01:11:40.400 --> 01:11:43.860 on two parts of the question that I wanted you to answer. 01:11:43.860 --> 01:11:49.320 And I just want to comment that, in terms of active and passive sources, 01:11:49.330 --> 01:11:52.331 I think they’re complementary because you’ve – you know, 01:11:52.331 --> 01:11:56.360 when you get an opportunity to look at the data, you can look at various parts 01:11:56.360 --> 01:12:01.130 of the wavelengths, and if they match, it would give you a sense on your 01:12:01.130 --> 01:12:04.630 assumptions – whether you’re modeling in fundamental mode or whatnot. 01:12:04.630 --> 01:12:10.280 I don’t want to get into the weeds, but both approaches, when put together, 01:12:10.280 --> 01:12:17.060 gives you an additional support for your assumptions while you’re in the field. 01:12:20.400 --> 01:12:25.760 - Okay, can – will you go back to one of my phase shifts, 01:12:25.760 --> 01:12:28.360 and there’s another question. Go ahead. 01:12:28.360 --> 01:12:30.570 - I was going to ask you if you could talk about some of 01:12:30.570 --> 01:12:35.980 the limitations of – you really didn’t cover that very much. 01:12:37.480 --> 01:12:39.140 - Well … 01:12:42.000 --> 01:12:45.720 A real heterogeneous site … 01:12:48.400 --> 01:12:54.520 You won’t be able to evaluate that very well, potentially. 01:12:55.120 --> 01:13:01.680 But – and it didn’t come out in some of these – if we measure a 01:13:01.690 --> 01:13:09.690 real heterogeneous site, and we have a 500-meter-long wave, 01:13:09.690 --> 01:13:14.750 and we get good data, if the earthquake shakes that site, 01:13:14.750 --> 01:13:18.679 generates surface waves that are 500 meters long, 01:13:18.679 --> 01:13:22.949 and we don’t have nonlinear behavior, we have the signature of the site. 01:13:22.949 --> 01:13:25.510 So we call a lot of this the signature of the site. 01:13:25.510 --> 01:13:28.739 And I’m sorry that didn’t come out. I had it on a couple slides. 01:13:28.739 --> 01:13:33.400 But – so – but that may not be what’s governing the behavior. 01:13:33.400 --> 01:13:36.540 Because if it starts to go nonlinear, and it’s fractured rock, 01:13:36.540 --> 01:13:41.030 it’s going to behave very differently nonlinearly than linearly. 01:13:41.030 --> 01:13:47.700 So I know I’m going off on tangents and maybe not answering your question, 01:13:47.700 --> 01:13:54.349 but I think the limitations are how complex the underground is 01:13:54.349 --> 01:13:59.580 relative to what you’re applying and whether you need to – whether you 01:13:59.580 --> 01:14:03.500 can use a 1D approach, which is what we’ve been doing, or you 01:14:03.500 --> 01:14:10.580 have to start doing 2D or even 3D. And 2D and 3D, given the problems 01:14:10.580 --> 01:14:15.420 that we have with the profession right now with 1D profiling, is a real mess. 01:14:16.320 --> 01:14:19.510 So the people would not get – they can buy software. 01:14:19.510 --> 01:14:22.760 In fact, I got to be careful. 01:14:23.700 --> 01:14:27.520 Courses are offered to anybody that say you can be an expert 01:14:27.520 --> 01:14:32.429 in this in four hours. What the hell are you talking about? 01:14:32.429 --> 01:14:35.310 You can’t be an expert in four hours. 01:14:35.310 --> 01:14:39.120 You don’t even know what shear wave is. And you’re going to be an expert. 01:14:39.120 --> 01:14:43.900 So that’s one of the big problems, to me. And you know what that’s about? 01:14:43.900 --> 01:14:47.860 Making money. That’s about making money. 01:14:49.160 --> 01:14:54.300 I like money. But I like integrity too. 01:14:55.840 --> 01:14:58.239 I value that more than money. 01:14:59.120 --> 01:15:04.480 - Ken, thank you for the slides and your talk. 01:15:05.540 --> 01:15:10.300 I have a sort of – not directly related question, 01:15:10.309 --> 01:15:13.969 but I think that you’ll enjoy this question. 01:15:13.969 --> 01:15:18.900 As you know, there has been, and still are, a lot of discussion and 01:15:18.900 --> 01:15:25.440 disagreement and – going on on Vs30. Which side are you on? 01:15:25.440 --> 01:15:26.820 [laughter] 01:15:26.820 --> 01:15:33.180 - Well, that’s easy. Sometimes Vs30 is good. Sometimes it’s not. 01:15:33.190 --> 01:15:37.409 But if it were up to me – and by the way, I talked to one of the people – 01:15:37.409 --> 01:15:40.980 I won’t name them for fear that I got it a little bit wrong, but a very good friend 01:15:40.980 --> 01:15:45.330 of mine. And Vs30 was picked, you know, really at the start. 01:15:45.330 --> 01:15:51.030 Well, they can drill 100 feet and, you know, the profession will stomach this. 01:15:51.030 --> 01:15:54.969 And what can we do? I would much rather have Vs100. 01:15:54.969 --> 01:15:58.540 For me, I’d like to see what more of the profile looks like 01:15:58.540 --> 01:16:04.159 to see what things are happening. Could you find a dispersion curve? 01:16:04.160 --> 01:16:07.400 So the phase plot. Phase versus frequency. 01:16:08.420 --> 01:16:10.600 Can you find phase versus frequency for me? 01:16:10.600 --> 01:16:13.099 - [inaudible] 01:16:14.120 --> 01:16:19.120 - Yeah. Put it all up there. Okay. - So I’ve got a comment. 01:16:19.130 --> 01:16:21.559 And this might address what Rufus was asking 01:16:21.559 --> 01:16:24.449 and also what Mehmet was talking about. 01:16:24.449 --> 01:16:30.050 So, you know, in the last two years, I’ve been talking about this concept 01:16:30.050 --> 01:16:33.060 of measuring with a micrometer, marking with a chalk, and cutting 01:16:33.060 --> 01:16:36.720 with a hacksaw. So what’s the end product are you after? 01:16:36.720 --> 01:16:38.260 And so … - Mm-hmm. 01:16:38.270 --> 01:16:45.020 - In PSHA, you know, we have this really nice procedure 01:16:45.020 --> 01:16:49.429 that sucks in data that have high uncertainties. 01:16:49.429 --> 01:16:52.920 So Vs30 itself – you’re going after Vs30, 01:16:52.920 --> 01:16:57.110 you know, using these methods are certainly appropriate. 01:16:57.110 --> 01:17:00.080 - The phase. - Yeah. [inaudible] 01:17:00.080 --> 01:17:04.770 - Yeah. - However, if you’re looking to 01:17:04.770 --> 01:17:09.050 delineate detailed features – two-dimensional features, 01:17:09.050 --> 01:17:12.280 of course you don’t want to use something such as 01:17:12.280 --> 01:17:17.780 surface phase methods that assume a 1D response from your near surface. 01:17:19.409 --> 01:17:22.360 - Say again because I was thinking about this. Excuse me. 01:17:22.360 --> 01:17:26.090 - Oh, okay. So Rufus asked about, 01:17:26.090 --> 01:17:30.540 what’s the limitation of these methods, and Mehmet asked, you know, 01:17:30.540 --> 01:17:34.219 what do you think about Vs30, right? And so if you think about the limitations 01:17:34.219 --> 01:17:38.219 of these methods, coupled with Vs30, what we’re talking about here is, 01:17:38.219 --> 01:17:41.370 you know – and I want to bring the whole concept of measure 01:17:41.370 --> 01:17:45.260 with a micrometer, mark with a chalk, and cut with a hacksaw. All right? 01:17:45.260 --> 01:17:49.230 So if you are looking for really detailed information about the subsurface, 01:17:49.230 --> 01:17:52.180 you don’t want to – you don’t want to be using methods 01:17:52.180 --> 01:17:55.329 that assume a 1D response. You want to do something 01:17:55.329 --> 01:17:59.830 that’s 2D, 3D, something that’s much more complex. 01:17:59.830 --> 01:18:05.120 But if your end goal is to produce a Vs30 or a Vs profile for, you know, 01:18:05.120 --> 01:18:08.889 1D transfer function type of study or ground motion prediction equations, 01:18:08.889 --> 01:18:11.770 these methods are more than – more than adept at doing – 01:18:11.770 --> 01:18:15.659 you know, getting that level of data out. 01:18:15.660 --> 01:18:19.840 - So I’d like to come up with another conclusion. 01:18:19.840 --> 01:18:25.960 Surface waves have been fabulous for us looking into the ground to depths 01:18:25.960 --> 01:18:29.909 that we could never drill and giving us information you could never get 01:18:29.909 --> 01:18:34.699 with boreholes. You could never see these sites like we’ve done. 01:18:34.699 --> 01:18:40.560 So, yeah, surface waves have been the next generation of in situ 01:18:40.560 --> 01:18:46.320 seismic evaluations. Now, they have to evolve towards 2- and 3D. 01:18:46.320 --> 01:18:49.621 And that will be the big thing. But, oh, yeah, surface waves – I mean, 01:18:49.621 --> 01:18:52.400 I could never have done these things, most of them that I showed you, 01:18:52.400 --> 01:18:56.380 without surface waves, huh? So, oh, my gosh, the future, 01:18:56.380 --> 01:19:02.280 it just exploded because of that, and our better understanding of the ground. 01:19:05.440 --> 01:19:08.780 I don’t know why I didn’t say that at the start. 01:19:09.100 --> 01:19:14.599 But, no, it’s been very important. Now, so this isn’t part of the talk. 01:19:14.599 --> 01:19:18.280 It’s okay. You can get up and leave. We do this right now for 01:19:18.280 --> 01:19:23.320 spectral analysis of body waves – exactly that plot. 01:19:23.320 --> 01:19:28.860 And I will show you rock layers that you thought had a uniform velocity. 01:19:28.860 --> 01:19:31.760 And when you start learning how wavelengths are propagating 01:19:31.760 --> 01:19:35.760 at different velocities like that, it’s not uniform. 01:19:35.760 --> 01:19:39.389 And you’d be amazed at how many measurements you’ve made in situ 01:19:39.389 --> 01:19:46.409 with body waves that, they’re not wrong, but they’re a bit incorrect. 01:19:46.409 --> 01:19:49.739 So when I showed you field and lab data, 01:19:49.739 --> 01:19:52.699 probably the field data is also misleading us. 01:19:52.699 --> 01:19:56.739 And for the first time, one of the holy grails that I would always tell 01:19:56.739 --> 01:20:03.429 the class, that I’ve never accomplished, is in situ material damping. 01:20:03.429 --> 01:20:07.240 We are now doing it with spectral analysis of body waves. 01:20:07.240 --> 01:20:10.449 We measure dispersion in situ of body waves. 01:20:10.449 --> 01:20:13.670 We measure attenuation with body waves. 01:20:13.670 --> 01:20:19.330 I can identify materials in geotechnical soils better than other folks 01:20:19.330 --> 01:20:25.900 can because dispersion between clays and sands is hugely different. 01:20:26.680 --> 01:20:32.469 So the future is extremely bright for all types of geotechnical testing 01:20:32.469 --> 01:20:38.099 just because it’s so theoretically sound. And much of this stuff was discovered 01:20:38.099 --> 01:20:42.679 analytically a couple hundred years ago by mathematicians, and that’s all they 01:20:42.680 --> 01:20:47.460 had to do. They didn’t have any of the other stuff we have today. 01:20:51.500 --> 01:20:52.820 Yes? 01:20:52.820 --> 01:20:57.360 - Ken, quick question. You thought about Vs30, but [inaudible] … 01:20:57.360 --> 01:21:02.040 - Can I just give you the mic? - Basically – well, first of all, 01:21:02.040 --> 01:21:05.850 I’d like to say the impact that you and your program have had 01:21:05.850 --> 01:21:10.579 on site characterization from the point of view of utilizing 01:21:10.580 --> 01:21:14.180 surface waves has been tremendous. It’s been huge. 01:21:14.180 --> 01:21:21.179 And a little tidbit – I actually went back to Berkeley to study damping in soils 01:21:21.179 --> 01:21:23.519 by using the shake table. - Yeah. 01:21:23.519 --> 01:21:27.199 - And the surface waves generated by the – by the shake table. 01:21:27.200 --> 01:21:30.320 - He’s a good man. - So anyway, this problem’s 01:21:30.320 --> 01:21:32.160 been around a long time. - Yeah. 01:21:32.160 --> 01:21:35.050 - And surface waves, one of the big advantages that they have 01:21:35.050 --> 01:21:41.070 is that they’re easily generated. And of course, when you get to passive, 01:21:41.070 --> 01:21:45.740 all of our seismic noise and everything is associated with surface waves. 01:21:46.860 --> 01:21:50.520 But my real question has to do with the procedure that’s used. 01:21:50.520 --> 01:21:53.900 It seems that everything is – you’re doing from the point of view 01:21:53.900 --> 01:22:00.220 of surface waves is basically based on elastic theory or based on 01:22:00.220 --> 01:22:03.449 what we understand about trying to use a surface wave 01:22:03.449 --> 01:22:08.659 and dispersion curves and inferring the structure that way. 01:22:08.659 --> 01:22:10.800 - And “inferring” is the right word. - Right. 01:22:10.800 --> 01:22:14.020 - Mm-hmm. Mm-hmm. - So – but one of the things that 01:22:14.020 --> 01:22:18.110 occurs to me, since I had that little project at Berkeley that I was 01:22:18.110 --> 01:22:22.540 working on ended up – me solving a theoretical problem having to do with 01:22:22.540 --> 01:22:27.679 viscoelasticity or the existence of surface waves in an anelastic 01:22:27.680 --> 01:22:30.400 or viscoelastic environment. - Mm-hmm. 01:22:31.260 --> 01:22:36.420 - And basically, the theory associated with that indicates that one of the 01:22:36.420 --> 01:22:43.630 key things that – unique properties of a Rayleigh wave is the tilt of its particle 01:22:43.630 --> 01:22:49.239 motion ellipse. And that tilt is associated with the damping in the soils. 01:22:49.239 --> 01:22:53.429 And so my question to you is, is that when you’re putting out your sensors, 01:22:53.429 --> 01:22:55.480 you’re using only vertical sensors. Is that correct? 01:22:55.480 --> 01:22:59.500 - Correct. Correct. - If you were to also use horizontal 01:22:59.500 --> 01:23:02.540 sensors at the same locations … - Yep. 01:23:02.540 --> 01:23:06.600 - … you could probably get information on the tilt of that particle motion ellipse. 01:23:06.610 --> 01:23:08.719 - Interesting. - And that tilt of that particle motion 01:23:08.719 --> 01:23:12.530 will tell you – give you information about the damping. 01:23:12.530 --> 01:23:16.700 - It’s always nice to get good ideas from good people. 01:23:17.480 --> 01:23:22.060 That’s very interesting, and we have lots of 1 hertz horizontal phones too. 01:23:22.060 --> 01:23:24.220 We can easily do that. 01:23:27.900 --> 01:23:34.719 It’s probably – in that aspect, I probably enjoy working more 01:23:34.719 --> 01:23:39.150 in the laboratory looking at those things on our – on our specimens 01:23:39.150 --> 01:23:43.030 that we test in torsional shear and resonant column. 01:23:43.030 --> 01:23:46.969 And so I haven’t done – it’s hard for me to keep the lab 01:23:46.969 --> 01:23:52.900 and the field balls in the air together. And so I like to have other colleagues 01:23:52.900 --> 01:23:57.530 that I can interact with, and Professor José Roesset saved me on 01:23:57.530 --> 01:24:02.280 surface waves – I mean, with all of his – Kausel and Roesset and so forth, huh? 01:24:03.240 --> 01:24:10.220 But, yeah, damping – material damping is really complex. 01:24:11.060 --> 01:24:16.980 And I gave an invited talk. It just meant that – I think Alan – 01:24:16.989 --> 01:24:21.199 I don’t know who invited me at the SSA meeting last time. Do you? 01:24:21.199 --> 01:24:22.909 - Albert. - Albert did? 01:24:22.909 --> 01:24:25.120 Albert, were you the one that did it? - Yeah. 01:24:25.120 --> 01:24:30.700 - Okay, Albert. Well, I got to be careful what I say here. 01:24:32.000 --> 01:24:37.660 But when – we now can – because of improved instrumentation, 01:24:37.670 --> 01:24:42.030 we can make strain measurements. We can measure the properties – 01:24:42.030 --> 01:24:48.030 material damping and stiffness at 10 to the minus 6 percent. 01:24:48.030 --> 01:24:52.960 That’s 10 to minus 8th strain. If you [blows out] do that to 01:24:52.960 --> 01:24:55.720 our equipment, you screwed up the measurement. 01:24:55.720 --> 01:24:59.540 And so, I mean, we find a very nice linear range. 01:24:59.540 --> 01:25:06.180 Now, from damping point of view, we find a very nice hysteretic linear range. 01:25:06.190 --> 01:25:10.239 We find a very nice equivalent viscous damping linear range. 01:25:10.239 --> 01:25:16.230 So I’m down here with hysteric. So this is damping on an arithmetic scale. 01:25:16.230 --> 01:25:20.630 This is log scale down here. This is 10 to the minus 6, 01:25:20.630 --> 01:25:23.159 10 to the minus 5, 10 to the minus 4, 10 to the minus 3. 01:25:23.159 --> 01:25:27.070 We might go over five log cycles, maybe four. 01:25:27.070 --> 01:25:30.521 This is going to be equivalent viscous. This is – and so that’s free 01:25:30.521 --> 01:25:33.659 vibration decay. That’s also the width of the response curve. 01:25:33.660 --> 01:25:38.020 When you’re in the linear range, they give the same number. 01:25:38.020 --> 01:25:43.159 And then this hysteric is you – you’ve got the hysteresis loop. 01:25:43.160 --> 01:25:47.360 And the hysteresis loop, if you have no friction in your systems, 01:25:47.360 --> 01:25:52.340 [claps] has a curved end. A curve. It’s not pointed. 01:25:52.920 --> 01:25:56.400 Like they would always use for hysteric, huh? Oh, it’s got a pointed end. 01:25:56.400 --> 01:25:58.560 Yours are curved. They’re no good. 01:25:58.560 --> 01:26:03.400 Okay, sometimes I don’t like it when I don’t get, you know, proper respect. 01:26:04.800 --> 01:26:08.159 That was a joke. Sorry. I’m the only one that enjoyed it. 01:26:08.159 --> 01:26:10.280 No, but the – so I was showing them 01:26:10.280 --> 01:26:15.150 the curved ends and so forth, and it’s – we have very little data 01:26:15.150 --> 01:26:16.920 on this, so I got to be careful. 01:26:16.920 --> 01:26:22.500 But here is viscous. Here is linear. Here’s kappa – 30 hertz. 01:26:22.500 --> 01:26:26.420 Here’s earthquake – 1 hertz. That’s hysteretic. 01:26:26.420 --> 01:26:28.889 They’re going along like this. This is strain. 01:26:28.889 --> 01:26:32.960 We’re gone through a couple log cycles, and then they cross. 01:26:33.880 --> 01:26:40.500 And the hysteric is very, very sensitive to number of cycles. 01:26:40.510 --> 01:26:43.820 So it’s coming down, but the complexity and 01:26:43.820 --> 01:26:49.160 damping is all I’m trying to say after all that, is so huge. 01:26:50.040 --> 01:26:56.989 That’s where theory – there isn’t a lot of theory, it seems, that people understand. 01:26:56.989 --> 01:27:01.360 So there could be theory out there. I don’t follow it much. 01:27:01.360 --> 01:27:06.139 But there’s just a wealth of things to do to try to understand the materials and 01:27:06.139 --> 01:27:09.309 then see, once you understand them, how you’re going to use them. 01:27:09.309 --> 01:27:11.380 And it’s just like that. 01:27:11.380 --> 01:27:16.280 I’ve been wanting to do spectral analysis of body waves for a long time 01:27:16.280 --> 01:27:22.680 since we started with surface waves. And wow, it really is good. 01:27:22.680 --> 01:27:27.500 And for a lot of soils and so forth – and that’s how come I can prove 01:27:27.500 --> 01:27:30.659 crosshole is better than the others because you stay in the layer. 01:27:30.659 --> 01:27:33.840 And I know you guys always get after me for refraction, but you stay 01:27:33.840 --> 01:27:37.329 in the layer. But if you do a typical downhole test, 01:27:37.329 --> 01:27:41.321 even a seismic cone test, so – in the field, and you’re hitting with 01:27:41.321 --> 01:27:47.880 a long plank, the bulk of your energy might have a wavelength of 6 meters. 01:27:49.140 --> 01:27:53.200 And how often are you making your measurements? Every 1 meter. 01:27:53.200 --> 01:27:58.740 Bologna. No, no, no. You don’t know what’s in that 1-meter layer. 01:27:58.750 --> 01:28:01.850 You got a 6-meter-long wave passing it. 01:28:01.850 --> 01:28:05.489 But until you start understanding what’s really going on out there 01:28:05.489 --> 01:28:08.699 and see how it impacts your measurements – I’ve been doing it 01:28:08.699 --> 01:28:11.370 for a long time, and I didn’t know it, huh? 01:28:11.370 --> 01:28:16.840 I didn’t pay any attention to it. But, so again, there’s such sound 01:28:16.840 --> 01:28:20.770 theory behind all this that there are improvements 01:28:20.770 --> 01:28:23.460 for the young people to make. 01:28:23.460 --> 01:28:29.040 While I sit on the beach having mai tais in Hawaii. It’s okay with me. 01:28:29.050 --> 01:28:31.380 - Well, thank you, Ken. There is another group that has this 01:28:31.380 --> 01:28:35.280 room at noon. And I’m – but I’m sure we could keep you here for a while. 01:28:35.280 --> 01:28:37.050 So thank you again, and … - You know … 01:28:37.050 --> 01:28:38.440 - … come up and harass him later. 01:28:38.440 --> 01:28:40.060 [Applause] 01:28:40.060 --> 01:28:44.520 - I am leaving here feeling very bad about those slides. I am so sorry. 01:28:45.720 --> 01:28:49.000 Holy moly. - [inaudible] that and take it from you. 01:28:49.000 --> 01:28:57.480 [Silence]