PAGER - Common Building Types
This building type is typically one or two stories and used for single-family housing. It is predominantly built in the areas of extreme temperature such as desert or cold-weather, or other inhospitable climates. It has a large mass and basically no strength, particularly against out-of-plane wall forces. In the 2003 Bam earthquake, collapse of these buildings was widespread and contributed to many of the 43,000+ deaths. The typical mode of collapse is out-of-plane failure of the walls, resulting in loss of support for the roof.
Reference: EERI and IAEE\'s World Housing Encyclopedia (Report #104) - Mehrdad Mehrain, Farzad Naeim
Stone masonry with timber roof
Stonework buildings are a common type of rural construction in many parts of Iran. It is widely used in the mountainous areas because of the ease of attaining the building material. Unfortunately, these buildings are often found in highly seismic parts of Iran. The building materials consist of stone, wood, mud mortar and straw. The major elements of these systems are stonewalls with mud mortar which carry both gravity and lateral loads. For reasons of thermal insulation the thickness of these walls is not less than 50 centimeters (usually 70 centimeters). The roof includes wooden joists and a set of secondary joists which are plastered with a thick layer of mud. Some of the seismic deficiencies of this construction type are: the presence of a heavy roof; out of plane failure of the walls; poor shear capacity of the mortar; inadequate connection between roof and walls; inadequate connection between intersecting walls; and lack of diaphragm action in floors and roof where the roof elements (wooden beams) do not work together in earthquakes and may collapse.
Reference: EERI and IAEE\'s World Housing Encyclopedia (Report #114) - Masoud N. Ahari, Alireza Azarbakht
Four arches (Char taaqi) with dome-roof structures
The 'Four arches' or Char Taaqi (in Persian) derives its name from the four arches that connects the tops of four timber or masonry piers enclosing the space. It is an equilateral architectural unit consisting of four arches or short Barrel vaults between four corner piers, with a dome over the central square; this square and the lateral bays under the arches or barrel vaults together constitute a room of cruciform ground plan. The structural system was developed about 2500 years ago, after the earring system in the Old Persian Empire (Sasanian age). The main goal of this building system was to create wide openings at four sides of the structure. This building system was used for special places that carry a high population, like fire temples (placec where Persians worshiped the Fire God), mosques, bazaars and other public places. This construction type may be highly vulnerable to earthquake ground shaking.
Reference: EERI and IAEE\'s World Housing Encyclopedia (Report #117) - Nima T. Bekloo
Earring system (Shekanj) with dome-roof structures
This construction type derives its name from the four earrings that are constructed at the four corners of a rectangular building at the spring level of the dome roof. This structural system was developed due to the lack of wood and stone. This technique was prevalent more than 3,000 years ago, after the invention of the dome-roof structures in the Old Persian Empire (Ashkanian and Sasanian). In this, once the walls were constructed, four earrings (shekanj) were built upon four corners of walls intersections, and then it was much easier to build a dome over these. Due to weak and brittle material used in its construction, this type can be highly vulnerable to earthquake ground shaking.
Reference: EERI and IAEE\'s World Housing Encyclopedia (Report #118) - Nima T. Bekloo
Steel frame with semi-rigid ("Khorjini") connections and jack arch roof ("Taagh-e-Zarbi")
This construction type is common in both urban and rural parts of Iran. It is a low-rise residential construction with a special kind of steel framing with heavy brick infills as partitions. Roof girders are connected to the supporting columns by means of semi-rigid connections. Diaphragms may range from flexible to rigid depending on the detailing and the construction quality. The structure is extremely heavy because of the brick infills between the roof beams. The roof is constructed in the form of a shallow arch called a 'jack arch'. Roofs, ceilings, and floors constructed in this way contributed to building failures in many recent earthquakes in Iran.
Reference: EERI and IAEE\'s World Housing Encyclopedia (Report #25) - Arzhang Alimoradi
Semi-rigid braced steel frame
This housing type is commonly used for low-rise building construction in Iran, mainly for multi-family dwellings. This structure is characterized with a special type of semi-rigid beam-to-column connection called "Khorjinee connection". This connection consists of a pair of continuous beams spanning over several columns and connected to the column sides by means of angle sections. Beams and columns are welded to the angle section. A major problem with the Khorjinee connection is that it is very difficult to improve the rigidity of the connection in the weak direction (the direction perpendicular to the connection) since the crossed beams are connected to the web of Khorjinee beams.
Reference: EERI and IAEE\'s World Housing Encyclopedia (Report #26) - Behrokh H. Hashemi, Mohsen G. Ashtiany
Confined brick masonry building with concrete tie columns and beams
This is a typical confined brick masonry housing construction common in rural areas of Iran. This building type is often used as a single-family house. Brick masonry shear walls confined with concrete tie columns and beams provide earthquake resistance in both directions.
Reference: EERI and IAEE\'s World Housing Encyclopedia (Report #27) - Behrokh H. Hashemi, Faramarz Alemi, Mohsen G. Ashtiany
*Building types and their descriptions are taken from the World Housing Encyclopedia (WHE) database when available or based on additional research performed by the PAGER team. This information is provided with the understanding that it is not guaranteed to be correct or complete, and conclusions drawn from such information are the sole responsibility of the user.