[Applause]
So, let’s get things started with the 30th anniversary of the Loma Prieta
earthquake, and our moderator is going to be Carol Prentice. Woo hoo!
[Applause]
- Well, we only have two speakers, so I’m just going to go ahead
and call them up. I am going to keep you guys on time.
So, Steve Hickman is going to be talking about advances in earthquake
science monitoring and hazard assessments since Loma Prieta.
- Thank you, Carol. And, to help me stay on time,
I brought my wristwatch up.
So thank you all, again, for being here.
Bring up my talk.
[Silence]
Oh, there we go. Okay.
So I’ll be talking about advances in earthquake science hazard assessments
and monitoring since Loma Prieta. If the microphone stays more or less
in place. There we go. Okay, so I hardly need to remind
most of you that this earthquake struck a little over 30 years ago.
Sixty-three people died. Thousands were injured.
Between 6 to $10 billion in property loss.
It was the largest earthquake to hit the Bay Area since the great
San Francisco earthquake of 1906. It was truly a wake-up call for
the Bay Area. Made everyone realize that the threat is real.
Started doing ShakeAlert – ShakeOut exercises.
And it’s important to note that most damage resulted from
enhanced ground shaking at distance.
Liquefaction was important but not a dominant factor.
So I’ll talk about that a little bit later.
The earthquake also motivated new research on source characteristics,
recurrence behavior, and consequences of earthquakes, leading to re-evaluation
of hazard. Led to enhanced earthquake monitoring, better hazard
characterization, situational awareness, and, as Sarah mentioned,
earthquake early warning, and spurred investments of
73 to $80 billion to retrofit or strengthen/replace vulnerable structures.
So I will do a fast round through this series of topics – earthquake geology,
paleoseismology, seismic monitoring, geodetic monitoring,
fault segmentation, ground motion forecasting, landslides and liquefaction,
and, if the hook doesn’t come in and pull me off,
investments in mitigating risks of future earthquakes.
So, first talking about earthquake geology.
A lot has happened since the earthquake.
It was certainly a catalyst for renewed studies of Bay Area faults,
with trenching, as you see here, at the Tyson’s Lagoon site along
the Hayward Fault. Led to significantly improved
view of location, style, and rate of rupture on faults.
And it got us better dates and magnitudes of past earthquakes,
slip rates on major faults, and there was little information on these factors
prior to the Loma Prieta earthquake. This was input to earthquake rupture
probability and fault-specific scenarios as well as the U.S. National Seismic
Hazard Maps, and very importantly, it made the public aware that
earthquake hazard is real and spread across the entire Bay Area.
This is a photograph of the Tyson’s Lagoon trench site from
Jim Lienkaemper et al.’s work. This is a classic site along the Hayward
that allowed, as you see below, us to get a record of recurrence repeat of
12 earthquakes on the Hayward Fault over the past 2,000 years.
So, since Loma Prieta, one of the most important advances in earthquake
geology was Lidar topographic data. And this is – the first Lidar was done
in northern California in 2003, mapping the locations of faults,
selecting sites for studies, revealing faults in previously
hard-to-find places, and helped to refine the Alquist‐Priolo Act zones
and accelerate selection of paleoseismic sites.
Also advances in geochronology, as mentioned here.
Other advances that helped earthquake geology – remote sensing, including
satellite and Lidar repeat imagery. Advances in photogrammetric
software – the 3D reconstruction using aerial and UAV photos
for slip rate recurrence. And, as I mentioned before, long paleoseismic
records plus synthesis of multiple sites along individual strands and segments.
This is a photograph, or a map, from Dave Schwartz’s paper in 2014
simply showing how many sites have been investigated in the
Bay Area since Loma Prieta. About 90% of these little green dots –
each one is a paleoseismic trench site – has been done since Loma Prieta.
Seismic network also – coverage has increased dramatically since
the Loma Prieta earthquake. On the left, you see what it
looked like in 1989. Each dot is a station.
On the right is what it looks like today. You can see a lot more dots.
So there’s been an increase in the density of seismic stations
by about a factor of 4-1/2. The data is now available in real time,
whereas, in 1989, many stations were not telemetered, and you
had to download the data manually.
This increased coverage allows for improved ground motion models,
more accurate earthquake detection location characterization, and more
important – very importantly, more data on soil/basin/rock shaking.
This is an example just showing how the data has improved.
On the left, you see what it looked like in 1994.
Back then, most of our stations were analog.
There were very few truly digital stations.
Sometimes stations were digitized in the office, but that was slow,
and often the velocity centers were clipped, as you can see
a lot of clipped records on the left back in 1994.
2003 to 2018 – more and more digital stations.
Most of the network is not digital with strong motion instruments added.
You can see in the middle, and especially on the right-hand side,
the data is much more on scale. Wide range in terms of amplitudes.
Wide dynamic range. And also wide frequency response.
Broadband instruments are much more prevalent than they used to be.
And, of course, the telemetry has improved as well.
So, with time, more and more digital stations, higher-quality data,
and you see there’s less move-out on the right-hand side.
More stations close to the earthquakes. That’s very important.
I mentioned strong motion stations. This is just a cartoon showing what
the distribution of the Advanced National Seismic System strong motion
stations, and other strong motion stations, operated by other agencies,
such as the Corps of Engineers shown in blue, how they cover the country.
These data are critical and have been – include both free-field
and building instrumentation. This is really important for capturing
strong motions in the near-field and also, as it would show on the right,
building response. So this is wherewe in the earthquake business interfere with –
[chuckles] interfere – interact – sorry. That was not Freudian.
[laughter] So we interact very closely
with the earthquake engineering community.
In fact, we have earthquake engineers on staff for that very purpose.
And looking at how buildings respond during strong earthquakes,
such as the Atwood Building in the 7.0 Anchorage, is critical to us.
Because you can see how the ground moves and then see how the building
responds, both translationally in terms of torsion, and other kinds
of modes that help engineers design buildings for better resilience,
better energy dissipation, and, in some cases, base isolation.
So our interaction with the engineering community through the strong motion
stations has been very important to us. And there’s some spectacular videos
on the web that Mehmet Celebi has put together if you want to see
how these buildings actually moved during the earthquake.
I’d encourage you to look that up.
Another advance since Loma Prieta – we’ve gotten a lot better
at locating earthquakes. No surprise.
The Waldhauser, Waldhauser, and Ellsworth techniques for
relocating and identifying repeating earthquakes have led to
much more detailed mapping of fault geometries and slip style along faults,
particularly for creeping faults, which produce a lot of background
microseismicity. You can see on the left-hand side, northern California
seismic system locations and the networks. These two panels
on the lower left are traditional network locations.
These ones over here are from relocations.
You can see in cross-section, streaks, clusters, and also the details
of the distribution of unstably sliding versus creeping fault behavior
that were previously invisible to us.
This other side here shows what’s being done now.
We are now routinely using double- difference activities – relocation of
earthquakes in northern California to produce a much sharper image.
Here is the traditional HypoInverse earthquake location.
Here are the relocations done as shown in this paper by Waldhauser and Schaff
along the same faults – the intersection of the San Andreas and the Calaveras.
So you can see a lot of details sharpening up – seeing more faults,
seeing more repeating behavior, and getting a much sharper picture
of what the fault looks like. The next step with the system is
to apply machine learning to earthquake detection, location,
and characterization. This is active area of research
for us, and we hope to be implementing it soon.
So, due to the advances in monitoring and data processing, we have a lot
more products – real-time products than were available before.
This is a timeline showing what we’ve had available over time.
Loma Prieta, we basically did earthquake locations in magnitudes.
Rather labor-intensive. Took a long time.
Now we get earthquake locations out in a matter of minutes, or seconds,
in the case of earthquake early warning.
We started to do Did You Feel It reports and ShakeMaps around the 1998 era.
Then we had finite fault solutions and ShakeCast to look at damage.
Moment tensor solutions for the earthquakes.
Then we had web services kicking in around 2011 with scenarios –
ground motion scenarios. Loss and injury estimates in PAGER.
And then internet services.
Now we are doing landslide and liquefaction forecasts
as real-time products, which are very important for us and have
been used and then calibrated, actually, in studies – post-earthquake
studies in Anchorage. We also do a 2-PAGER product now,
which incorporates FEMA’s Hazus estimates into the traditional
PAGER loss estimates. And we have aftershock forecasting.
I wanted to mention the aftershock forecasting is a new thing for us.
It’s a real-time product. It went live in September of last year.
And it’s been a very high-impact product for the – for the 2018
Anchorage earthquake, where it was done essentially manually by our team.
Same for the 6.4 and 7.1 Ridgecrest earthquakes.
The Navy was extremely interested in this. We worked very closely
with them on producing timely aftershock forecasting.
And, most recently, the Puerto Rico earthquake sequence that started
in December 2019. Doing aftershock forecasts for that continuing series
of earthquakes has been very helpful to the people of Puerto Rico.
I want to point out there’s an earthquake early warning session.
That’s a big thing. I’m not going to talk about that at all
because of time, but there is a session on that this afternoon.
Talk a little bit about ground deformation here.
There are reasons to measure ground motion deformation.
I think you all know, if we’re looking at strain accumulation, aseismic slip,
and possibly for early warning.
That’s something we’re investigating very actively.
Prior to 1989, we used two-color lasers and actually flew airplanes
to get line-length changes in these trilateration surveys
as shown here in the Loma Prieta area.
That was very time-consuming, and the surveys were infrequent as a –
as a result of that.
Now, of course, we use GNSS, or GPS, for continuous and
campaign monitoring. This just shows a vector displacement
field across northern California. Gradients going from, of course,
the North American Plate here to the Pacific Plate here.
And those, of course, give us information on loading rates
along faults that are useful in hazard assessments.
You can see down here is an example from southern California.
The continuous GNSS data provides very important data here on
displacements during earthquakes, then the post-earthquake relaxation
process, strain accumulation, earthquake, post-relaxation.
Again, this tells us a lot about the physics of the earthquake loading
system, both from adjacent faults and from below.
Some of the technological advances since Loma Prieta.
They really were well-illustrated by the Napa earthquake.
We use InSAR now, as shown here.
The south Napa earthquake broke along this fault here.
The colors give you a change in range to the satellites.
So this helps us map out deformation, and the arrows are from GPS receivers
on the ground showing relative displacement.
One of the things we learned from Napa was that the fault
doesn’t slip all at once. There was a large component of slip
in the northern area that was coseismic. That would be up here – sorry, up here.
But, in the south, the coseismic slip at the surface was relatively small.
But, over time, the slip started to accumulate, going up here to more
and more displacement over a period of about a year after the earthquake.
So this postseismic slip, it turns out, is an important hazard, especially
if you’re trying to mitigate and reconstruct lifelines, gas pipelines,
water lines, roadways, etc. Because the Earth keeps moving
after the earthquake. So this is an important thing for us
to understand and is now including in the HayWired scenario.
Postseismic afterslip is also shown here by this GNSS campaign
station down here, which keeps moving after the earthquake.
We also use Lidar to map offsets across faults.
This is shown by work here by Ben Brooks.
You can see displacements across the fault going here.
And we also use borehole strainmeters, which, in many cases, were installed
by the USGS for the Plate Boundary Observatory.
Last but not least, I want to mention one of the important uses
for high-rate GNSS. Certainly did not – is a recent thing –
was constraining the source mechanisms of big earthquakes.
So I’m just showing this as an example from Sarah Minson’s work.
This is the Tohoku earthquake – Tohoku-Oki earthquake in 2011 – 9.1 –
showing how these displacement vectors from GNSS receivers in Japan
were used to constrain the slip distribution during that earthquake.
This is the coverage of GNSS stations in western U.S. today.
We have a lot of stations in California and in the Pacific Northwest.
So we’ll be able to use those to help constrain subduction zone
events in the Pacific Northwest impacting northern California
as well as potentially along the San Andreas system.
Seafloor geodesy – I wanted to throw in a pitch for that – is something
that’s an important new avenue. This shows seafloor acoustically
coupled geodetic transducers offshore in Japan.
Displacement vectors that were huge compared to what was on land allowed
them to map out the distribution of slip as you approach the trench axis.
And, as you know, there was a huge tsunami after this earthquake.
This gives us new insights into the distribution of slip and why the slip
was able to propagate and, in fact, increases displacement toward
the surface, which resulted in the devastating tsunami.
Fault complexity in multi-segment ruptures become more evident
since Loma Prieta. Show here the example from
Denali with multiple sub-events comprising the main earthquake.
We’ve also see this with Landers, Izmit, Tohoku, and Kaikoura.
There’s another session on that this morning talking about Ridgecrest
lessons learned. Uniform California Earthquake Rupture Forecasts.
This brings all this together – geology, geodesy, seismology, paleoseismology.
We’ve been forecasting the probability of earthquakes along the San Andreas
system since 1988. There was a forecast that showed the Loma Prieta segment
to be relatively high hazard, but we’ve gotten a lot better at this using all these
data forms brought together. And there’s a session tomorrow
afternoon about seismic sources in California.
So UCERF3 has been a very important product for us.
High-performance computing has enabled that and similar studies.
This is a close-up of what’s shown for the San Andreas Fault system
in the Bay Area. And you can see – you’ve seen this all before –
high potential for earthquakes from the UCERF3 model for the Bay Area.
There’s been a stress shadow here, as seen after the 1906 earthquake,
a relative paucity of earthquakes after that event.
And here we are with Loma Prieta.
The Ridgecrest – I mean, sorry – the Loma Prieta earthquake was
a take-off for a lot of stress shadow studies that started soon after that.
I’m showing an example here from Reasenberg and Simpson’s paper
in 1992 and a lot of other work since then on static stress changes,
dynamic stress changes – both nearby, as it might affect dynamic rupture
between segments, and distance, such as triggering remote activities
from Landers, and longer-term viscoelastic effects.
I want to talk a little bit about scenarios.
Scenarios have been a – have really been critical for a number of
earthquakes, not just scenarios of ground shaking in the west in the U.S.,
but also Salt Lake City, Flagstaff – other parts of the country –
New Madrid and Virginia. And they’ve been very helpful
in informing emergency response exercises and planning to do ShakeOut,
which I show here, and the HayWired earthquake scenario in California.
One thing we learned about Loma Prieta was damage is
amplified at distance. So you can see here – of course,
a lot of damage in Santa Cruz and in the Santa Cruz Mountains
during the earthquake, but also a lot of damage done at the
Cypress Viaduct and in the Marina District.
Most of the casualties – most of the loss of life was in the viaduct.
This is shown here as a consequence of the viaduct being located on
soft mud, which amplified ground motions relative to bedrock.
Also some reflections off the lower crust.
This is also the first implementation for earthquake early warning for
Loma Prieta, which gave – we put sensors near the epicenter
and gave people working at Caltrans on the viaduct structure up to
20 seconds’ lead time for impending shaking from aftershocks.
So we’ve learned a lot about Loma – since Loma Prieta about how
earthquake rupture processes affect ground motion.
We’ve learned about directivity.
We’ve learned about 3D structure effects, especially sedimentary basins.
We’ve learned about complex ruptures involving multiple faults.
And now we do the scenarios for major earthquakes.
This is just showing what we’ve done for the Hayward Fault
using this 3D model. It was created over a period of time,
and it’s still being worked on very actively in this center
and other USGS centers and with collaborators.
This model here shows ground shaking as a function of Modified Mercalli
Intensity along the Hayward Fault for an anticipated 7.0 earthquake
starting here and propagating bilaterally.
And it takes into account variations in creep along the fault.
This HayWired scenario was a very important product where we used
ground shaking science, liquefaction, landsliding, ground shaking,
and main shock/aftershock fault slip and afterslip to talk about fire following
earthquake, impact on lifelines, structures and codes,
and interdependencies, and now recovery and social
consequences of an earthquake and the society’s rebounding from that event.
Fire following earthquake is an important factor and is considered
in this scenario and could result in significant aggravation of losses
in houses and could have up to $30 billion in additional damage
due to fires, depending upon ignition and winds and other things.
U.S. National Seismic Hazard Maps have come a long way since
Loma Prieta. This is what we had to work with in 1996.
Hazard map for U.S. based on seismicity, basically,
and fault geometry. These were replaced in 1996
by the National Seismic Hazard Maps, which included geologic slip rates,
paleoearthquake data, multiple models for earthquake recurrence,
ground motion prediction equations, used spatially smoothed seismicity,
and various different source zones, depending upon the geologic province
and also using more ground deformation measurements,
especially in California, to constrain hazards.
So this is what the map looks like today.
Earthquake probabilities, as I mentioned, go into this.
Ground motions, site amplification.
Importantly, these maps are used to set provisions for building codes
and design earthquake-resistant structures and insurance rates as well.
The new release – 2018 – also includes the effect of sedimentary
basins for the first time. And, as you can see, in the
San Francisco Bay Area, this is looking at the 5-second spectral acceleration.
We see an increase in the East Bay around Walnut Creek.
Ground motions up to about 10 to 25%. In the San Jose area, ground motion
increases up to about 5 to 10%, depending on frequency, of course.
And, as I said, this is for 5 seconds.
We see most amplification in basins at long periods in this model.
Again, there’s an afternoon session on Wednesday talking about shaking.
So encourage you to stay tuned for that.
Liquefaction susceptibility. We’ve learned a lot about liquefaction
since – I’m sorry, since 1989. We know that liquefaction was
a big factor in the 1906 earthquake. This shows some buildings that have
tilted into their foundations due to liquefaction.
We now have liquefaction susceptibility maps and a map of liquefaction
potential for San Jose and East Bay alluvial plains based upon
cone penetrometer data. And this shows liquefaction susceptibility.
Red is very high, gold is high,
going down to very low in white, for the Bay Area.
An important consequence of the Loma Prieta earthquake was the
passing of the Seismic Hazard Mapping Act of 1990.
This was passed by California state legislature.
It directs the California Geological Survey to identify map zones that
are earthquake-prone for liquefaction and landslides.
It’s raised the standard of practice in the geotech engineering
community throughout the state. And it also shows the Alquist-Priolo
Act fault study zones that have to be avoided and treated specially
when they impact developments.
This is a map of the California Earthquake Hazard Zone Application,
which you can basically zoom in on and look at your parcel, and it’ll tell
you if you’re close to a fault zone through Alquist-Priolo Act,
liquefaction zone, landsliding zone. If you’re in one of these zones,
you will have to do site-specific investigations before you develop
or subdivide that. And also, you have to disclose that fact through real estate –
during real estate transactions. And last thing I want to mention,
that a lot of money has been invested in resiliency
since Loma Prieta – 73 to $80 billion.
And a lot of it’s on water, schools, unreinforced masonry –
in different counties. And this has been huge.
And I encourage you to read Tom Brocher’s Open-File for more detail.
So, in closing, it was a wake-up call for all of us.
Motivated new research – Loma Prieta earthquake – and certainly led to
enhanced monitoring for better hazard characterization.
And, for those of us who are scientists, really brought home the importance
of our science in reducing the risks, both by future earthquakes, the need
to work with engineers, emergency managers, and others to make sure that
our science has impact on saving lives, reducing injuries,
and increasing societal resilience. Thank you.
[Applause]
- All right. Thanks, Steve. We’re going to have a discussion
session at the end, so we’re just going to move on
to the next speaker now, who is Chris Poland.
Where is Chris? Oh, there you are.
Technical advances and remaining challenges since Loma Prieta.
- Nice to be here with you.
I have a hunch I may be the only structural engineer in the group.
Excuse me. Mehmet’s here. Good to see you again.
I got to get back to my talk.
I’m not a Mac guy. Can somebody help me with this, please?
- [inaudible]
I’m not a Mac person, either, but I stumble through this.
We have a Mac at home. There you go.
- Okay. I am a structural engineer, now retired CEO of Degenkolb
Engineers out of San Francisco.
I’ve spent my entire career in earthquake engineering as it
relates to the practice of building design and evaluation
and the development of community resilience.
So it’s a bit of a different perspective than what we just heard about,
though this is all extraordinarily important to us.
But I want to – I want to bring to you the perspective of a practicing
engineer that has been dedicated to community resilience but also
to trying to use the best earthquake science that you folks
bring to us in order to improve what we’re doing.
I had the good fortune, when I started with Degenkolb Engineers in 1974,
to have spent a little bit of time here just in an exchange program
with Chris Rojan. Now we’re talking about – [inaudible] you people hear
will know these names, I’m sure. But Henry Degenkolb, my boss and the
leader of our firm, and Fritz Matthiesen decided that it would be good for
Chris Rojan to spend a little bit of time in the design office and for me to
spend a little bit of time here just to try to get some connection going on.
And that has turned into a lifelong desire on both of our parts, I think,
to see the interconnection of earthquake science and engineering, especially
as it relates to – especially as it relates to strong motion and the use of strong
motion, which we still have, I must say, as engineers,
a long ways to go to appreciate the benefits that we have from that.
Steve has given you the introduction about the Loma Prieta earthquake –
1989. This was a great opportunity to look back at 30 years and see
what we’ve accomplished, and it really is pretty amazing.
I was 15 years into my career at the time that this
Loma Prieta earthquake occurred.
I was in a principal-level position. It was – it was devastating to hit –
it was the most devastating earthquake to hit San Francisco.
The thing that was interesting is that 27,000 buildings were damaged,
and only 63 people lost their lives. And I got to tell you that the
engineering community was feeling pretty good about what they were doing
at the time of the earthquake because of the lack of damage.
Of course, we really didn’t understand – and I’m remembering clearly sitting
in my office when the earthquake occurred, getting the calls,
and spending the next year of my life investigating damaged buildings
and working on repairing those.
And we were continuing to repair those things through my entire career.
But it became really important to us, and we came to understand,
that what this earthquake showed us was the vulnerability of our existing
built environment and the impact that that has on communities.
And it’s this whole notion about, what do you do with the existing
built environment that we have.
I went back to the National Research Council – that’s a member
of the National Academy of Science, Engineering, and Medicine –
to a group that they brought together – a symposium in 1993.
There may be a couple of you here that participated in that. I don’t know.
It was a great collection of earthquake scientists, engineers, and responders.
In this symposium, they went through and they said, well,
what have we learned after three years? What can we do, and where should
we head? And I thought this would be a good anchor.
I picked out a few things to talk about that they – that they recommended.
But they recognized that this was a very short-duration earthquake
that lacked in surface faulting for a magnitude 7.1.
Kind of sounds like Ridgecrest, doesn’t it?
Everybody says a 7.1 is not what’s expected. Okay.
There’s something there. Local geology had – we had site factors.
We understood about site factors. And we were building that into our
design, but we weren’t – we weren’t building it in in a way that was
the most significant, nor did we recognize how that changed
the risk to a particular site, when you have to consider the site factors.
We recognized and concluded that the mandatory state legislation that was
out there that had to do with schools – that came from 1933, the unreinforced
masonry schools, and they had been completely taken out
of the inventory by then. And hospitals – in a – it was 519.
Came after the San Fernando earthquake requiring California’s
hospitals to be constructed to higher standards and to remain functional.
That all happened before Loma Prieta. And the work that that had
accomplished was demonstrated. And we took good credit, I believe,
and assurance that we were in the right direction.
We recognized that that there was an urgent need to pay attention to
our unreinforced masonry buildings, and that led into a number of programs
into the nonductile concrete buildings and bridges.
The other thing that was recognized, I think, for one of the first times,
is the economic and social impact this had on our communities.
And there was quite a bit of research that was done – continues to be done –
try to understand that. And so much is going on now
to try to take that – what we were learning there and what we recognized
there and how that affects community recovery and build that into the
community resilience planning programs that are going on today.
Symposium came up with 40 recommendations.
You can see them here, and I want to just grab a few
of these recommendations. The general recommendations
really were a stern warning to the engineering profession,
I believe, that we’re not okay. We have not got this under control.
And, boy, 1994 Northridge told us that again.
It’s not enough to just save lives when our communities can’t recover.
Community recovery is very, very localized.
It has to do with a small area. And that has to be taken care of.
It has to recognize the impact we’re having – that our existing
built environment has on it. There were things to be learned
about engineering and – geotechnical engineering and structural engineering.
And we’ll talk a little bit about that.
And then, of course, planning and emergency response.
Steve showed you the picture of Algermissen and Perkins map.
What I’ve got next to it there is what we were using in 1985
in the Uniform Building Code for our design values map.
Maybe you’ve seen this thing. Maybe you haven’t. It has four zones.
The engineers drew this thing all by themselves because they really
didn’t have a good connection to the earthquake science community,
even though Ted Algermissen said, hey, come along in ’76, and gave us a map.
His map said that the ground shaking was upwards of 60% g acceleration.
And the engineers were using 10% g to design their buildings.
And the differences between 10% g and 60% g was unfathomable.
And the engineers didn’t understand why he could ever suggest such a thing.
And the reality is, they were completely talking about different things.
Engineers were talking about what they had calculated to be the strength
of buildings that had behaved well in earthquakes, thinking they
were the largest earthquakes. And the 1906 earthquake was one of
the key benchmarks that they had used. And buildings that had a strength in
the 3 to 4% range, that means their lateral strength – the way that
they calculated that, that strength was equal to 3 or 4% of its weight.
And that’s what they termed as acceleration.
And when the scientifically generated acceleration maps came along and
said 60% g, we couldn’t get there, and it was rejected, honestly. It was rejected.
After Loma Prieta, one of the things that I testified and –
invited to a field hearing. one of the things that I testified
is that we really had this discrepancy,
and we needed to do something about that.
We needed to get the engineers and the scientists in the same room.
The engineers needed to understand how important it was to have
a scientifically defendable map. And the scientists needed to understand
that we had to think about how we were thinking about our building designs and
how those two things came together. There’s a whole story there that
could be told, but I won’t tell it. We now have maps.
The wonderful thing is, is you can go to the website, as Steve mentioned,
and you can put in your lat/long, or your address for that matter,
and it’ll tell you your spectral acceleration.
It’ll tell you your peak ground acceleration.
And that’s all terrific. And that’s all built into the building codes now.
We’re doing a much better job. We figured out how to interlace
these two things so that the designs make sense.
Though you may know, or you may not know, that it drives engineers crazy
every time you change those values. And when you – when you’re reporting
them on a lot-by-lot basis, every time you change those values, you might say,
oh, it’s only 10 or 20%, you tell me I got to make my building 20% stronger.
That’s a big deal. And if it no longer meets the code, that’s a big deal.
And the issue is is that the buildings you’re building to resist the earthquake
doesn’t necessarily relate directly to that change in ground motion shaking,
as I hope you’ll pick up as I go along. There’s plenty for us to learn there
as we really fully understand the characteristics of the earthquake as
they relate to the – as they relate to the building performance.
The presence now that we have of liquefaction, landslide, and faulting
maps is extraordinarily important. We are moving into an era –
and you’ll hear me talk about this – we’re moving into an era where
we’re talking about community resilience and communities’ ability
to recover. The communities’ ability to understand where their
most vulnerable buildings are. Their most vulnerable buildings
and the ones that can be damaged can dramatically affect their ability
to recover are sitting on the bad soil sites.
Or they’re sitting alongside the fault. Or they’re sitting in landslide zones.
Property owners generally cannot afford or don’t want to spend the
money to have detailed studies done about whether their site
has liquefaction potential, landslide potential, or if they –
they want to trench their site to see if they have a fault.
So it’s extremely important that we have these maps.
We’re developing techniques. The maps are getting better.
They’re becoming more street level, that we can see them.
That’s extremely important. The thing is, we need these maps.
Every community needs these maps in a general sense in order to do
their community resilience planning. This is not the – this is not the great
work of earthquake science, I’m sure. Though earthquake science will lead us
to the techniques that are necessary so we can have the computers
draw the maps for us, and we can get the information
at the ground level that is so desperately needed.
The National Research Council recommendations said that we
needed to develop on-time, real-time monitoring systems capable of
producing intensity maps for use in emergency response planning
and execution. And this has been just dramatic.
Loma Prieta – that map that sits over on the – on the left-hand side there,
I just remember – I remember seeing that within a little while
after the earthquake occurred, and we knew where the fault was.
We knew where the epicenter was. We knew that it ruptured in
both directions. And we knew that there was building damage,
as Steve had explained, but it didn’t make a lot of sense.
My experience was in San Jose the night of the earthquake.
I went down there to investigate at Kaiser Hospital that we had
been studying. We were doing a lot of work for Kaiser.
And my partners and I spread out across the Bay Area to look at these hospitals
to make sure that they were safe to continue providing service.
And I had no idea – I thought I was driving into the epicentral area.
I had no idea what I was driving into. The reality is – and, of course,
today I would know that that particular site only experienced 10% g.
Recorded acceleration. And all the reasons why that occurred.
But the reality is is the fact that we now have ShakeMaps, that we can
tell how strong the shaking is in a moment has a huge impact on
engineers’ ability to respond and look for damage and determine whether
a building has been damaged because it’s poorly constructed and it shouldn’t
have been damaged, or it has really received extremely strong shaking.
That makes a big difference to understand that.
Having the ShakeMaps available to us now is huge to be able to do that.
The other thing that the program has brought us with the monitoring
for strong motion instrumentation is we now have strong motion records
by the hundreds of thousands. And that’s wonderful.
Back in the days when all we had was 1940 El Centro,
everybody acted like that’s what earthquakes looked like.
And that’s the not the case. And, in fact, the duration,
the waveform, the frequency content, the intensity, the number of repeated
cycles of strong shaking all bear directly on how a building performs,
and that information is now coming to us, and it’s extremely important.
Over to Ridgecrest. This is – this is really [chuckles]
delightful for me. I visited the sites of damaging
earthquakes over my entire career – dozens and dozens of them.
And now that we have this kind of information, it’s spectacular.
I don’t run after earthquakes anymore. I get on my computer and look
at the information that you folks provide to us.
But, you know, it’s still not being used by the engineers, and that’s
what bothers me so much. We had – we had the Ridgecrest earthquake.
We had a ShakeMap that told us that we had two significant hotspots
at both ends of the fault. When you look about building damage,
you can’t – you can’t talk about the whole area. You’ve got to talk
about what’s going on in particular sites and how that [inaudible].
And when you look at the waveforms at the – just over this short area,
look at the waveforms that we were able to record.
They have a – there’s a significant difference in those waveforms
and how – the impact that they’ll have on buildings.
And so, when we were talking about community resilience and predicting
damage, we need to understand what’s causing the damage
and be able to predict it. We’ve got to understand how
the waveforms are really affecting particular structures.
And every structure type – there’s, like, 13, 15, 20 types,
depending on how you like to count – responds differently to these
waveforms. And that’s what’s so important about understanding
where those come from. And I understand that there’s
a huge amount of uncertainty in predicting that.
The National Research Council said that practicing professionals
need to know more about bridge and building performance
during earthquakes with the use of instrumentation.
As Steve showed, that the instrumentation programs are there.
We’re instrumenting buildings. The California state program
is instrumenting buildings. We’re instrumenting buildings
under ANSS nationwide. This is all terrific.
This particular building in Watsonville recorded the Loma Prieta earthquake.
It had been instrumented, as you can see there, with a few instruments
that would help show us what the mode shapes were and how much torsion
there was and how much uplift it was. It’s a four-story reinforced concrete
shear wall building. Extraordinarily strong, solid building.
It was designed, actually, by the people at Degenkolb before I got there
as a telephone exchange building. And they knew that if they made it
solid and strong that it would be able to withstand all the
earthquakes that it needed to. We’ve been through a lot of that.
The records that came through clearly showed the kind of
performance that we expected. The thing that was so surprising
about this, which really changed the course of a little piece of earthquake
engineering, was the amount of strong shaking that the building experienced
over time and how that related to some rapid seismic analysis
procedures that were being – that we were all using to decide
when a building was going to be unacceptably damaged.
And that procedure said, this building, given this ground shaking, should have
been unacceptably damaged, and it wasn’t. It wasn’t even close.
And that caused a dramatic change in that procedure.
And it’s really – this kind of an experience has really moved us
away from considering just the response spectrum, peak ground
acceleration first, then we start [inaudible] spectral [inaudible].
Now we’re looking at the time history records as a way of
better understanding how our buildings are going to perform.
You remember I said that the whole thing is about understanding
how the existing built environment is going to behave.
And that understanding requires us to get a real close look at what causes
a building to be damaged or not. We’re going to – one of the reasons
I think we have so much trouble advancing our earthquake mitigation
programs – again, on the building infrastructure side, is it costs too much.
It’s just – communities look at this, and it just – they see billions of dollars.
And, as we can use better Earth science, better engineering,
better interconnection, better analysis procedures, we’ve got better tools –
as we can do that to get the price down, to be able to pinpoint where we really
need to work, that’s going to make a huge difference.
The National Research Council recommended that practicing
professionals need to develop refined techniques consistent with historic
behavior of structures for designing new and retrofitting existing
buildings and informing owners of the expected performance.
1989 we said that. We’re still saying that today. [laughs]
I wish I could say we were getting it done.
This whole notion of being able to design and retrofit buildings
for an expected performance has been around for a long time.
Some firms like ours were doing this.
Most firms were not doing it, either because they didn’t know how
or they were afraid to do it because they didn’t want to talk about it.
After the 1994 Northridge earthquake, that kind of pushed us even farther
as a profession and said, we’ve got to get this under control.
We had friends at the national level that money came available to the structural
engineers to write down what we’ve been talking about for years.
And that’s, what is performance-based seismic engineering?
We called it Vision 2000. Because we’re engineers,
and we understand what causes buildings to be damaged.
There’s really five pieces to this puzzle.
First, you’ve got to set out what you expect to have happen.
That’s the first part of performance-based engineering.
And that is, do you want the building to just save people,
or do you want it to remain functional, or something in between.
You’ve got to develop and verify your conceptual design.
You know, when you start from scratch as a designer, you’ve got
a blank piece of paper. The way that building is going to
behave has an awful lot to do with how it’s built and how it’s configured
and where’s it located, what kind of foundation it has.
And all that happens at the conceptual stage.
That has to be thought of in the beginning.
Then you’ve got to design the thing and draw it and specify it and verify it,
do the structural and non-structural, the contents, the utilities.
You’ve got to do that whole, big package, where most of the
interest is in people, when they want to talk about building performance.
But then, one of the most important things is you’ve got to get the
thing constructed properly. It has to be designed properly,
and it has to be inspected while it’s being constructed.
I can’t tell you how many times we’ve gone to earthquakes and seen damage,
and we said that there’s a construction problem here.
Or there’s a design problem here that should have been taken care of.
And then the building has to be maintained.
Vision 2000 introduced this idea – or, I should say, cataloged the idea
that there were performance levels that we could strive for.
The bottom was collapse. Collapse means collapse,
and it falls down, pancake, everybody loses their lives.
Near collapse is a building that you’re trapped inside of
that you can’t get out of. If you’ve dropped, covered, and held,
and you’re lucky that nothing fell on you, you’re going to
still be alive, but you’ve got to be rescued.
Life safe means that you’re safe inside that building and able to
get out on your own power. Immediate occupancy means the
building can – you can go back into it. You may not be able to use it, but you
can at least get in it and start repairing it so you can get it
back to some level of usability. And then operational says it’s
fully usable, just as if the earthquake hadn’t happened.
Those performance levels make sense, and they’re a continuum.
We’re can strive toward those. We made those names up
all by ourselves, and they didn’t – they didn’t resonate very well
with the communities.
Because they didn’t really touch what the community was interested in.
Honestly, they never really understood what all those terms meant.
I must say that most of my fellow structural engineers didn’t fully
understand what all those terms meant. But it started a process.
And this is – this came out of Loma Prieta and Northridge.
That performance – taking that process and bringing it to California,
installing performance-based design, those principles, into our building
codes started after that happened. In 1985, before Loma Prieta, our
Uniform Building Code was based on, like I said, 10% g with some variation.
But it was based on prescriptive requirements.
You followed the requirements, and the building would perform.
There was no explicit promise of performance.
Though there was – the engineers talked among ourselves, and we talked
about how our buildings were going to perform.
The fact that they would be safe, that they would be – most of them
would be repairable and usable, but that was just never talked about
in the – in the public sector.
By 2019, we had gone from a Uniform Building Code
to the California Building Code with many iterations.
It’s now developed by the State of California, and it’s adopted
locally with amendments. So each local community adopts
the code with their own amendments if they want to have amendments,
but the code is written by the state. It’s based on a national model code,
and it’s written by engineers that come together – a few – a few Earth scientists
that are willing to weigh in with the engineers, which is very important.
But the International Code Council puts this together with the
building officials in the end. And it’s based on standards
that are written by engineers. Now I want to emphasize that
[chuckles], because, when you get right down to who’s deciding
how we’re going to build our buildings or how we’re going to do our lifeline
systems, and what’s the acceptable level of risk, it falls to the earthquake
science professionals to do that. And that’s good.
That’s a nice place to be, but we – this process says that we have to
agree on what we’re going to do. And it’s a very lengthy process
you go through to make sure that we’re agreeing.
But it means we have to speak with one voice at the end of the day.
And it really is a challenge to all of us – and I’m not complaining about anybody
[laughs] – it’s a challenge to all of us to understand the big picture,
understand what we’re all contributing, and really work towards speaking
with this common voice. Where this really – where this
really lands a lot is in the hazard levels that we design to.
Traditionally, we’ve designed to a 475-year or 500-year earthquake.
The code talks about a 2,500-year earthquake.
We like to talk about lots of different kinds of things and
how that’s going to change. But to the – to the policymakers
and the code writers, we need to agree that there are times we want to use that
2,500-year earthquake and times we want to use that 500-year earthquake.
That’s what the community has agreed to.
That’s what we need to hang on to.
The two standards that are used in the building code are ASCE-7
and ASCE-41. 7 is for new construction,
and it defines performance today in four risk categories and
designated occupancies. So it still doesn’t describe performance.
It just says Risk Category 1, 2, 3, and 4.
That doesn’t help us too much. ASCE-41 really has grown up and
been based on the principles of Vision 2000 and gives us the
performance levels that we talked about. All new buildings must conform
to the California Building Code. Existing buildings – and this is
extremely important, and maybe you understand this, but existing
buildings do not need to conform. They only need to conform to the
code provisions under which they were designed.
And that means that, since I believe that our codes are really getting to
where we’re in a pretty decent place with buildings in the late ’80s, early
‘90s, anything that was built before that doesn’t meet that standard, and is
going to be the source of the problem. And when we talk about damaging
earthquakes, we’ve got to take a look at when the building was built.
Is it a non-conforming building that we knew was a problem, or is it
a new building that we are really surprised at what’s happened?
And what we’re finding is that it’s the old buildings that are the problem, and
we’ve got to continue to point to that and not continue to act like there’s
something wrong with how we’re designing our new buildings.
Hopefully, ASCE-7, the new building design standard, is going to declare
performance by 2030. Now, remember, in 1989,
the NRC got together and said, you guys need to do this right away
because you’re not telling the owners what’s going to happen.
And this is a particular pet peeve of mine, as you can tell.
The new building code’s not going there, and it’s not going there
for a long time. ASCE-41 is already there.
It grew up since 1984 going through different steps.
The most important thing that I can say is it provides three tiers of seismic
evaluation and retrofits, so we can talk about how existing buildings
are going to perform. I’ve got a quick example I wanted to show you.
One of my projects down at Stanford University that illustrates those three –
those three tiers of – those three levels of evaluation.
Just a little structural engineering for you.
This is the Mitchell Earth Science Building. You may recognize it.
This was before it was seismically retrofitted.
Went through the Loma Prieta earthquake.
Experienced some cracking. Went under evaluation.
It’s a four-story building that has this very tall third story, which is
the library area of the building. And its first-tier analysis is
a deficiency-based analysis. We look at the building, and we
figure out what its deficiencies are in terms of structural characteristics.
This is a concrete moment frame building.
It has a list of potential deficiencies. And, in Tier 1, you decide
which ones matter. In this case, it was a soft story,
shear stress check – that’s how strong the building is,
and the nonductile concrete detailing, which is how much reinforcing seal
is in the beams and columns and the joints.
The linear elastic analysis that you use in Tier 2, which is basically
what we’re doing with the code today – the linear elastic analysis would
recommend that we add all those purple shear walls to the building.
That’s to get the building to be strong enough to match those techniques,
to get the building to be strong enough. It would have a huge impact on
the use of the building. Visually, it would be awful.
And nobody would really want to do it, and it costs a lot of money.
That’s the simple story. The thing we did after that –
and we were early adopters in this. This has now become very
commonplace, is do the Tier 3 analysis where you go through
and you do a nonlinear analysis. And it’s really a displacement-based
analysis. And, in the displacement- based analysis, instead of deciding
how strong the building is and how much it would displace,
you focus on how much it will actually displace using a time history,
response history, or a pseudo-response history analysis.
How far is it going to deflect?
And can I handle that level of deflection with the kind of building that I have?
And what we determined was is that this particular building only needed
to arrest its deflection a little bit. And you can see in the corners –
we were fortunate we had corners with narrow columns.
We could put concrete walls in there that would act as backstays, if you will.
It would arrest the displacement to the point that we were satisfied that the
building would not only be safe but probably be usable after an event –
much higher level of performance than we could get by the
old response spectrum analysis. We could add those shear walls
and limit the drift. We could do that work while the
building was being used, and it was. It was done that way, though
I understand from folks that were in there, it was a little bit noisy.
But you didn’t have to evacuate the building, which is huge.
That’s one of the biggest costs of retrofit.
And the university could make a good investment in their response.
You look at the building today, you’ll see those skinny shear walls
down in the corners, and the library remains open and beautiful.
And that’s the – that’s a great story.
But, you know, when you do an analysis that’s displacement-based,
you got to know how many peaks of acceleration you’re going to have.
You have to know what the frequency content is.
Because the way that building behaves over time, and how much
it’s going to displace, depends on how much it’s going to break up.
And how much – and, in the process of it yielding,
what the consequence of that is. So that’s why it’s so important to
think about these earthquakes more in terms of what the – what the
content of the time record is. Frequency and content, number of
repeated cycles, amplitude, duration – all that is extremely important and
will affect how these buildings behave. We only analyzed this building for
one response spectrum because that was a long time ago.
Today, we’re using multiple time history analysis to do that to try to
capture the uncertainty in the variation.
You could argue, there’s too much uncertainty. We can’t get there.
I would argue, we have to get there. And we’ve got to – we’ve go to
figure out how to put our bounds around the uncertainties that we have.
Because every day, we’ve got to do our work.
We’ve got to work on buildings. We’ve got to design new ones.
We have to retrofit buildings. It’s all part of the hassle we go through.
Okay. Another part of that thing from the National Academy was to
make sure you inform owners of the expected performance.
And there is, in just the last couple of years, three programs that have come
along that are predicting performance in a way that the public can see.
These are LEED-style programs.
Let me back up a second. All three of the programs
have the basic concepts. They rate buildings.
This is the USRC Building Rating System.
They rate buildings based on safety, damage, and recovery.
Safety has to do with whether you’re likely to be killed as opposed to –
unlikely that you can’t get out of the building.
Damage has to do with how much it costs to replace.
40% damage usually means that a building is completely destroyed
and needs to be replaced. That’s what we’d like to not get to.
And then recovery, now we talk about in terms of days,
weeks, months, and years. And so, given those kind of metrics
to work with, and they have stars that they work with on that, they come back
with a LEED-style platinum, gold, silver, and certified rating that gives
a building owner a sense and an explanation about how his
building is going to perform and what he can expect.
Because we have not talked about it – because, Loma Prieta, they said
everybody was surprised, everybody is still surprised, this is supposed to
be the tool that we can use to get the community to start to understand.
As I understand it, there’s a half a dozen of these ratings on buildings right now.
And, by the end of next year, there should be 40 or 50 of them.
And hopefully, it’s going to begin to snowball.
You’re going to begin to see this. It’s based on a lot of assumptions,
but it’s still a very important step from not knowing at all and
expecting everything’s going to be fine,
to having a good idea about how your building’s going to perform.
Okay, the last thing I wanted to talk about is the National Research Council
said we need to adequately inform policymakers of the risks and costs
and benefits of various strategies and make strong recommendations
for earthquake risk mitigation.
Well, we’ve been talking about this kind of stuff for 60 years.
Unfortunately, we’ve been talking to ourselves.
We haven’t been talking to the policymakers.
And we’ve been changing our building codes.
You can read there how the codes have been changing over the decades
to try to accomplish this. What I’ll take you – I’ve kind of talked
a little bit about each one of those eras, including the performance levels
that we introduced in the ’90s. But, in the 2000s and going forward,
we’re now talking about building re-occupancy,
functional recovery time, community resilience.
And those terms are all under development.
And it’s been included in the recent NEHRP re-authorization –
National Earthquake Hazard Reduction Program.
That program was re-authorized, and it talks about that.
Another thing that happened – that was in the 2000s.
I really think that this all kicked off in my mind where we came together –
Carol, Peggy, we’re on this activity list – we came together, the Earth scientists,
SSA, USGS, the Earthquake Engineering Research Institute,
and the Office of Emergency Services. We put on a earthquake conference
commemorating the 1906 earthquake – 100-year conference.
Caught the attention of the world. Made a huge splash.
Wrote down – got together – did not happen overnight,
and wrote down these 10 top action items that needed to be done
to develop a culture of preparedness, investing in reducing losses,
and ensure resiliency and recovery. You can read through those.
Those are the essential features. And, since 2006, if you – if I could
take you through all that has happened in that 14 years, you can see that
this has become kind of the rallying cry for a lot of what’s going on.
And that’s important. And it’s because we came together,
and we worked together, and we put
our heads together, and we spoke with one voice.
That’s the big thing that I want to say. And don’t take me wrong.
I don’t suggest that you’re the ones that are not speaking with one voice
[laughs] because my colleagues have got exactly the same problem.
We’ve got to – we’ve got to do this, though.
The NEHRP program was finally re-authorized in 2018.
And that re-authorization really made a significant shift in the
NEHRP program thinking about individual buildings, systems,
and people to thinking about community resilience.
Just to quickly say that, when you look in the authorizing legislation,
which is part of the public law – this is in the law now.
This is what they’re supposed to do.
Expanded the findings, making sure that we have updated notion
of all the areas that were affected. Talked about a new conversation –
new language we put in there, declared that the built environment
has been constructed for life safety, not to remain operational or able to
recover under any specific schedule.
It’s important that congressional staffers read that, and they do.
And they understand that. It also reported the NRC findings
that said that we needed $300 million a year for 20 years
if we’re going to start to solve this problem.
If you haven’t seen that NRC report, it’s worth looking at.
Expanded the purpose of the legislation. And basically, what all these words
talk about are really, we need to think about community recovery now.
We’ve got to get to where we’re paying attention to what it takes
for communities to recover. This was all driven by what we –
what we learned from Katrina and other natural hazards that have happened.
We defined community resilience in that re-authorization.
I say “we” because there were groups of you and groups at EERI
that worked together to get this to happen.
Expanded the program activities – I think this is important.
Published a systematic set of maps for active faults, folds, liquefaction
susceptibility, susceptibility for earthquake-induced landslides and
other seismically induced hazards. Continue the development of ANSS,
including earthquake early warning. The reason this needed to get into
the re-authorization is so the funders would understand
that Congress wanted this done.
Because the biggest barrier we have to getting maps for
all of our significant communities is the funding that’s required.
And then this expanded definition of the Interagency Coordinating Council –
because there’s four agencies that are involved in this program –
is really all about getting a common budget, getting these guys
to come together, talk together. Congress wants the executive branch
to bring them recommendations that everybody stands behind
to enforce this one-voice notion that I was talking about.
Also in that re-authorization was a call for a special studies.
Two of them are really important. One is by the general accounting –
the comptroller general, which is going to look at the NEHRP program
over the last – through its entire life and decide how well we’ve done.
And talking to Keith and Steve – they were just talking to the
[inaudible] guys yesterday about this. So this is good.
Because what they’re going to learn is that we’ve got a lot done,
but we’ve got not nearly as much done that we want to get done because of
the problem we have with funding. And the other things is, NIST and
FEMA were commissioned to develop options for improving
the built environment in terms of buildings and critical infrastructure
and to reflect re-occupancy and functional recovery time goals.
So that’s this new place that we’re going with community resilience.
And just to say a few words about that. As you know, communities today
are unique, they’re diverse, they’re historical.
They have substantial built environment that’s sub-standard.
They’re challenged by shocks and stresses.
There’s all sorts of problems that communities have that
they need to spend money on. Earthquake engineering is not one.
They have limited resources. They need to form –
informed decision-making. They need us as earthquake scientists
and professionals to come alongside and give them that idea.
We have – we have now gone to community resilience,
and we’re looking very closely at the interaction between social functions
that are listed there on the left-hand side, and the built environment –
energy, transportation, buildings, communication, water, and wastewater.
With the recognition that everything we do to the built environment
is to serve the social functions. That’s what it’s there for.
And the social functions cover everything.
And, in fact, we need to look at that. We need to pay attention to the social
functions so that we can determine what needs to be done to our existing
environment in order to start to improve the resilience of our communities.
The NIST Community Resilience Planning Guide was published
back in 2015. I worked on this project for five years.
It’s kind of what I did at the last part of my career. I’m still doing it now.
I shouldn’t say the last part. [laughs] This phase. That’s what we’re doing.
It talks about bringing a community together, putting together a planning
team, understanding what your vulnerabilities are, determining goals
and objectives, figuring what the anticipated performance is,
understanding what the gaps are, and then getting about –
getting those things corrected. Like I said, this problem is
insurmountable, but it is being brought under control.
A community has a chance to bring it under control.
Over on the left-hand side over here, we have what we call building clusters.
And they are clustered around essential facilities, critical facilities, emergency
housing, housing in neighborhoods, and community recovery.
It recognizes that, for a community to recover, it needs to have its critical
facilities during the emergency response period, but it needs to have its housing.
Because it’s got to have – because people have to be able to
go back to work, have to be able to have their housing.
They’ve got to be able to get their kids in school, have their small business
districts available to them. The hospitals and the MOBs
have to be available. Or else they won’t stay in their community.
And this is extremely important. That’s probably the most important
thing that a community could do is
to bring its building stock and lifeline systems and support – the people
together so that the workforce is there to restore their economy.
This is all – a whole big program, another lecture, but the reality is
is the green and yellow and orange boxes are the goals in terms of days,
weeks, and months and years. The blue boxes are an illustration
of where we are today. And in communities, the intention is
to look at where we are today, where they need to be, and use that as a tool
to understand how they’re going to improve their community resilience.
Understanding where they are today and how to get to the better future
is right at the heart of really good earthquake science and engineering.
That’s what we do.
The better tools that we have, the better we understand,
the more localized it can become, and it’s all done at the community level,
the better off we’re going to be able to serve our communities.
So there’s a series of performance categories now.
These are new terms that are just being introduced.
They come out of that report from the NEHRP re-authorization.
FEMA and NIST have a project going with ATC right now that define these
opportunities we have to improve the resilience of our communities.
And I just wanted to tell you about these terms because this is – this is
the new version of that chart that I showed you that went from
collapse to operational. Re-occupancy means you
could get back in the building. That’s a – that’s a performance level
that we’re talking about. Functional recovery includes safe
occupancy, but it includes a building’s ability to do its most significant things.
Okay? It’s not full recovery. A full recovery is back to
pre-earthquake conditions. That’s for buildings.
For lifeline systems, we need to talk about operability.
These systems need to be back to near-normal service and functionality
where they’re working normally.
And, you know, the whole thing – I haven’t said it yet, but I want to say,
the whole thing with lifelines get extremely complex because
we have to look at the ground shaking and vulnerability over
a large area with the lifeline [inaudible].
And that’s a – that’s a whole new area of us to deal with.
So, to adequately inform policymakers and make strong recommendations.
I think that some – just a couple of summaries here.
We need to adapt our new and existing building designs in a way
that generates public understanding. We need common hazard levels,
which means that we all got to come together and agree on what these
common hazard levels are and then provide the information to support that.
We’re on our way there. We’re working on that now.
It’s just – it’s going to become more complex.
We need to define and declare performance levels and include
expected time needed for re-occupancy and functional recovery.
Time to restore. That’s the important thing.
We need to allow for community adaptation and advocate for
community resilience. And lastly, I just want to say, my – since I –
going to give you remaining challenges. In my humble opinion, the biggest
remaining challenge that we have since Loma Prieta are adequate funding
for research and tool development. And that runs with Earth science
and engineering. Community-level seismic hazard
maps nationwide related to faulting, landslide, liquefaction,
and strong shaking. I have helped communities put these
programs together, and this is huge. To be able to understand this.
Because they just can’t go out and do this on their own.
Calibrate structural analysis tools suitable for design and usable
to define functional recovery. And incorporate those into ASCE-7 and 41.
That’s our new building design standard and existing building
design standard. Get the building performance rating system implemented
and getting those seals all over the place so everybody understands
what we’re dealing with. Participate in community resilience
planning and implementation through codes and standards.
And then enact public policy that supports community-based
risk mitigation. The last thing I’ll say there, it’s not like
we haven’t been trying to do this. We’ve been trying to do this
for a long, long time. Probably longer than I’ve been trying to do it.
And I’ll count 40 years. But what I’ll say is, we’ve got to
recognize we need to do something different.
We need to talk about this differently. We’ve got to figure out how to get to
a point that we believe the money should be spent, and our policymakers
and our communities believe the money needs to be spent,
so that we can improve the community resilience and
the thing that we’re all striving for. Thank you very much.
[Applause]
- All right. Thank you.
Thank you to Steve and Chris. [laughs]
We’re going to have 15 minutes of discussion now, and we have
somebody running around with a microphone, so questions.
First question. - [inaudible]
So this is for Chris, and it has to do with your point number two.
USGS and CGS, for a long time, have been producing hazard maps
with landslide and liquefaction at 1-to-24,000 scale.
That works for us. There are regional data layers available.
And, philosophically, that’s about where we leave off and expect the
site-specific studies should take over. But there are cities who would
like more detailed maps. That’s tremendously expensive
to try to produce [inaudible] maps with more detail.
I’m wondering if you think the breakdown – how we see this.
Should we continue working at 1-to-24,000, or should we try to
get much bigger pots of funding and produce more detailed maps?
- Yeah. In the – in the community resilience planning thing that I showed,
we have different building clusters that we like to talk about and
things that we’re going to depend on in a short period of time
and a long period of time.
If you go out and – if a city goes out and inventories its public schools –
because they need schools, they need to know if those schools are sitting on
liquefaction sites or landslide sites, or if they’re sitting next to faults.
Now, 1-in-24,000, you kind of get an idea.
You can’t tell too much around the periphery.
And you can’t – you can’t expect a city to have the money to go
and do the detailed studies. Now, there’s probably detailed studies
that have been done, but there’s no mechanism that I know of to
gather that information of the process. So then you say, well,
whose responsibility is that? And that gets down to [laughs]
who’s got the money. The city is never going to have the money.
The building folks don’t want to have to spend the money.
And if you’re talking about landslide, I mean, if you’re in a large area,
obviously, and you own a piece of it, you can’t study the whole area.
You don’t want to study the whole area. So it comes down to recognizing this is
something that needs to be done. And I recognize that there’s more
research necessary to try to get better benchmarks and metrics
so we can do it at a finer scale. And then somebody’s got to draw
the map on a – on a GIS platform so you can figure out what it is.
And so who can do that? In the NEHRP re-authorization,
the reason we wrote that in there, a way to get it, we’re trying to
say to the agencies, the national – the federal government is going to do this.
That they want their communities to do this.
Is it going to – do you do it with the money that you get today?
No. Not even close. Do you need a whole new special
fund to do this sort of thing? Yeah. You need recognition
that that’s important. So that’s how [inaudible].
[Silence]
- Chris, I’d like to follow up on that if I may.
I have a hearing deficiency. I didn’t hear everything that Keith said.
But your response kind of left things hanging.
If 24,000 isn’t good enough, what is?
Do we go to a scale of 100 foot to the inch?
That’s not something that the U.S. government …
- Well, you know, again, if you’re … - So, what’s sufficient?
- It has to be on a – it has to be information on a lot-by-lot basis.
- [inaudible] - Well, it’s out of reach.
Maybe it’s out reach. Maybe it’s not.
We have – we have information on strong shaking, whether we are
all comfortable with the uncertainty that’s built into it or not,
we have information on strong shaking lot by lot right now.
Give me the address. I’ll tell you what the strong shaking
is going to be for the engineers. We’ve got that.
Yeah, we do. Just … - [inaudible]
- It’s … - We have estimates lot by lot,
but it’s not measured lot by lot. - No. If I want to design a building
on a particular site, whether you like how the information was
put in there or how it was done, I can get an answer about what my
seismic design parameters are lot by lot. Now, what does that mean if I want
information for liquefaction and for landslides?
Well, I need a new set of metrics, right? Somehow.
And I need a new way to characterize the risk and what’s going to happen.
And then I’ve got to have tools that are able to do the same thing they did for
strong shaking to get it down to some kind of a statement
about what’s going on lot by lot. It may take 100 years.
I don’t know. It doesn’t bother me.
I’m just saying that, if we want to – if we want to get the community
resilience and be able to give communities the tools that are
necessary so they can figure out where they are, they’ve got to
be able to have that kind of information.
Or, they’ll greatly benefit from that kind of information. How’s that?
- My name is Jim Baker, and I’m the county geologist in Santa Clara County.
Been doing that for 25 years. Jim Berkland did it for 21 years before me.
We have detailed hazard zone maps.
Some of them were developed by the state and then adopted by the county,
and then USGS developed more maps. The state developed more maps.
Those have been incorporated into our maps.
It’s all available on the GIS.
I use that on a daily basis when I’m evaluating applications for
development, applications for building permits, new buildings,
additions to existing buildings. That information is the basis for
making a decision as to whether or not that applicant has to hire a private
consulting engineering geologist or geotechnical engineer to
perform a site investigation. That’s the key.
And then, having a certified engineering geologist or a registered geotechnical
engineer on staff at the jurisdiction to evaluate the adequacy of the report of
that investigation is the second key. And finally, implementation in the
design where that information is conveyed to the design engineers
in such a way that they can incorporate it into what they want to build.
And finally, verifying that it actually gets constructed that way.
So I think our system is working.
And I think having information developed at 24,000 scale and
incorporated into what local jurisdictions do is working.
I am a little wary when we present a fault map and zoom in on
an individual parcel, and the owner says, well, the fault’s mapped
in my backyard, not under my house. And we have to say, well, it is plus
or minus a few hundred feet. The reason for the zones is
just like you having a smoke alarm in a building.
It goes off. That doesn’t mean the building is necessarily on fire.
It means there’s smoke. Now you got to find out why there’s smoke.
So our zones are the early warning system.
We have a question as to what those conditions really are at that site,
and it has to be investigated. And then it’s the process for
incorporating it into what actually gets constructed.
I think it’s working.
I think 24,000 scale is a viable way for information to be developed.
As long as it’s qualified when you present that information.
That those lines – that’s the problem with GIS.
[laughter]
Well, a good example would be Hitchcock and Kelson’s photolineations
map that they developed right after the Loma Prieta earthquake.
I utilized that. And when I digitized those, I digitized them as polygons
rather than lines. So, when you zoom in on a GIS, what is presented as an ink
line on a published map gets bigger and bigger and bigger as you zoom in on it.
And it makes it more realistic at the parcel scale as to the fuzzy boundaries.
The problem with GIS is a lot of things are – especially zones are drawn
with a line, like the Alquist-Priolo earthquake zones is a line.
And I have guys – parcels that come in that are half in and half out.
- Well, what I’ll say is, I’m going to take everything you said in support of what
I said, except maybe the 1-in-24,000. I will say that we have thousands of
jurisdictions in California, tens of thousands across the country,
the don’t have the benefit of what you have. I believe.
- [inaudible] - No, no. No, no.
You’re great, Jim. - [laughs]
- Hey. You got it under control. We’ve got all these other folks
that need the same thing. And that’s – I take what you’re telling
me, other than the nuts and bolts of the details of how specific it is,
as supportive of what I’m trying to say. And from a – if you go to a city –
some city – I don’t know, Antioch. And they’re trying to do community
resilience. And maybe they’ve got maps. I don’t know.
I’m – maybe I got the wrong – I’m trying to get to a small city
that’s trying to do something. I know the little place I live in southern
California now, they know nothing about this stuff. [laughs]
And it’s – and that’s part of what this recommendation is about.
- [inaudible]
- Well, I moved out of Walnut Creek five years ago.
And I loved that place, and I don’t know where they are [inaudible]. [laughs]
- [inaudible] Walnut Creek, and I have a question.
[laughter]
I also work with the California State Guard,
and I move a lot of data about these earthquakes to them and try to connect
them with the right people so they use the information right.
But I have a specific question about what cities can do for creating –
what kind of value they can get from doing building inventories.
Structural analysis to some point so that they understand a lot more about the
pre-1980 buildings that you want – that I took that you wanted us to focus on.
- Yeah. At the – at the heart of the NIST Community Resilience Planning
Guide is the answer to that. And there’s a whole – a whole
conversation that goes on there. But basically, when a community like
Walnut Creek sits down and says, okay, the earthquake has occurred.
The response is successful. Now we’ve got to recover.
What buildings do you need in Walnut Creek in the first few days,
in the first weeks, in the first few months – what buildings and lifeline
systems do you have to have in order for your city to recover so people will
stay and be a part of the recovery? Okay, so, as soon as you’ve identified
those buildings, then you’ve got to go about the process of figuring out
whether you have them or not or what you’re going to – what you’re
going to do in order to get that to occur.
That’s – to me, it’s a question of not, how do I get everything fixed.
It’s a question of, how do I identify what I’ve got to have
in the first few weeks? And I happen to think it’s housing.
What do I have to have in the first few weeks?
What part of the – of the lifeline system do I have to re-engage
and make useful in the first few weeks so my city can recover?
And that’s – to me, that’s the secret to this.
Because, in a lot of cities, it’s a small thing.
You’ve got a brand-new city hall – almost brand-new.
Ought to be okay, right? Should be good.
You’re sitting on good land. You’ve got freeways.
You’ve got that gigantic overpass. Ought to be okay.
So anyway, that’s the point is you want to – you want to look in closely
and find out what needs to be done. Safety we always have to do.
I mean, we just have to worry about where the – where the massive
unsafe conditions are and get those taken care of.
But this – what I’m talking about here is, what do we need for recovery?
How do – how do we – how do orchestrate recovery?
I talked to our city manager in my little town of Canyon Lake, 12,000 people,
down by Lake Elsinore. And he said, oh, we know. We know.
We’ll just – we’ll get it done. [laughs]
Okay. You’re going to get it done. How you – how’s your building?
I don’t know. But we’ll figure it out. [laughs]
- Well, if there’s one more short, quick question?
If not, we’ll [inaudible].
[Applause]
- Okay. Thank you, everyone. As Carol just said, we are
breaking until 10:45. There is coffee outside.
Please pay for snacks if you haven’t yet because we don’t have funding for that.
We are fronting the month for that. Please pay.
But most importantly, if you are a speaker, do not go.
Come, if you have not already given us your slides and make sure that we have
your slides if you would like to have slides for your talk.
And also, lastly, there is exciting fire-related equipment outside.
If you want to stretch your legs, go on down to the parking lot
and enjoy the Menlo Fire Department.
[inaudible background conversations]