Earthquake-resistant structures

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Model of the Gaiola pombalina (pombaline cage), an architectural, earthquake-resistant wooden structure developed in Portugal in the 18th century for the reconstruction of Lisbon's pombaline downtown after the devastating 1755 Lisbon earthquake Gaiola pombalina.jpg
Model of the Gaiola pombalina (pombaline cage), an architectural, earthquake-resistant wooden structure developed in Portugal in the 18th century for the reconstruction of Lisbon's pombaline downtown after the devastating 1755 Lisbon earthquake

Earthquake-resistant or aseismic structures are designed to protect buildings to some or greater extent from earthquakes. While no structure can be entirely impervious to earthquake damage, the goal of earthquake engineering is to erect structures that fare better during seismic activity than their conventional counterparts. According to building codes, earthquake-resistant structures are intended to withstand the largest earthquake of a certain probability that is likely to occur at their location. This means the loss of life should be minimized by preventing collapse of the buildings for rare earthquakes while the loss of the functionality should be limited for more frequent ones. [1]

Contents

To combat earthquake destruction, the only method available to ancient architects was to build their landmark structures to last, often by making them excessively stiff and strong.

Currently, there are several design philosophies in earthquake engineering, making use of experimental results, computer simulations and observations from past earthquakes to offer the required performance for the seismic threat at the site of interest. These range from appropriately sizing the structure to be strong and ductile enough to survive the shaking with an acceptable damage, to equipping it with base isolation or using structural vibration control technologies to minimize any forces and deformations. While the former is the method typically applied in most earthquake-resistant structures, important facilities, landmarks and cultural heritage buildings use the more advanced (and expensive) techniques of isolation or control to survive strong shaking with minimal damage. Examples of such applications are the Cathedral of Our Lady of the Angels and the Acropolis Museum.[ citation needed ]

Some of the new trends and/or projects in the field of earthquake engineering structures are presented.

Building materials

Based on studies in New Zealand, relating to 2011 Christchurch earthquakes, precast concrete designed and installed in accordance with modern codes performed well. [2] According to the Earthquake Engineering Research Institute, precast panel buildings had good durability during the earthquake in Armenia, compared to precast frame-panels. [3]

Earthquake shelter

One Japanese construction company has developed a six-foot cubical shelter, presented as an alternative to earthquake-proofing an entire building. [4]

Concurrent shake-table testing

Concurrent shake-table testing of two or more building models is a vivid, persuasive and effective way to validate earthquake engineering solutions experimentally.

Thus, two wooden houses built before adoption of the 1981 Japanese Building Code were moved to E-Defense [5] for testing. One house was reinforced to enhance its seismic resistance, while the other one was not. These two models were set on E-Defense platform and tested simultaneously. [6]

Combined vibration control solution

Close-up of abutment of seismically retrofitted Municipal Services Building in Glendale, California Municipal Services Building-1.jpg
Close-up of abutment of seismically retrofitted Municipal Services Building in Glendale, California
Seismically retrofitted Municipal Services Building in Glendale Municipal Services Building.jpg
Seismically retrofitted Municipal Services Building in Glendale

Designed by architect Merrill W. Baird of Glendale, working in collaboration with A. C. Martin Architects of Los Angeles, the Municipal Services Building at 633 East Broadway, Glendale was completed in 1966. [7] Prominently sited at the corner of East Broadway and Glendale Avenue, this civic building serves as a heraldic element of Glendale's civic center.

In October 2004 Architectural Resources Group (ARG) was contracted by Nabih Youssef & Associates, Structural Engineers, to provide services regarding a historic resource assessment of the building due to a proposed seismic retrofit.

In 2008, the Municipal Services Building of the City of Glendale, California was seismically retrofitted using an innovative combined vibration control solution: the existing elevated building foundation of the building was put on high damping rubber bearings.

Steel plate walls system

Coupled steel plate shear walls, Seattle Pages from Kharrazi 0002.jpg
Coupled steel plate shear walls, Seattle
The Ritz-Carlton/JW Marriott hotel building engaging the advanced steel plate shear walls system, Los Angeles LA LiveTower05.jpg
The Ritz-Carlton/JW Marriott hotel building engaging the advanced steel plate shear walls system, Los Angeles

A steel plate shear wall (SPSW) consists of steel infill plates bounded by a column-beam system. When such infill plates occupy each level within a framed bay of a structure, they constitute a SPSW system. [8] Whereas most earthquake resistant construction methods are adapted from older systems, SPSW was invented entirely to withstand seismic activity. [9]

SPSW behavior is analogous to a vertical plate girder cantilevered from its base. Similar to plate girders, the SPSW system optimizes component performance by taking advantage of the post-buckling behavior of the steel infill panels.

The Ritz-Carlton/JW Marriott hotel building, a part of the LA Live development in Los Angeles, California, is the first building in Los Angeles that uses an advanced steel plate shear wall system to resist the lateral loads of strong earthquakes and winds.

Kashiwazaki–Kariwa Nuclear Power Plant upgrade

The Kashiwazaki–Kariwa Nuclear Power Plant, the largest nuclear generating station in the world by net electrical power rating, happened to be near the epicenter of the strongest Mw 6.6 July 2007 Chūetsu offshore earthquake. [10] This initiated an extended shutdown for structural inspection which indicated that a greater earthquake-proofing was needed before operation could be resumed. [11]

On May 9, 2009, one unit (Unit 7) was restarted, after the seismic upgrades. The test run had to continue for 50 days. The plant had been completely shut down for almost 22 months following the earthquake.

Seismic test of seven-story building

A destructive earthquake struck a lone, wooden condominium in Japan. [12] The experiment was webcast live on July 14, 2009, to yield insight on how to make wooden structures stronger and better able to withstand major earthquakes. [13]

The Miki shake at the Hyogo Earthquake Engineering Research Center is the capstone experiment of the four-year NEESWood project, which receives its primary support from the U.S. National Science Foundation Network for Earthquake Engineering Simulation (NEES) Program.

"NEESWood aims to develop a new seismic design philosophy that will provide the necessary mechanisms to safely increase the height of wood-frame structures in active seismic zones of the United States, as well as mitigate earthquake damage to low-rise wood-frame structures," said Rosowsky, Department of Civil Engineering at Texas A&M University. This philosophy is based on the application of seismic damping systems for wooden buildings. The systems, which can be installed inside the walls of most wooden buildings, include strong metal frame, bracing and dampers filled with viscous fluid.

Superframe earthquake proof structure

The proposed system is composed of core walls, hat beams incorporated into the top-level, outer columns, and viscous dampers vertically installed between the tips of the hat beams and the outer columns. During an earthquake, the hat beams and outer columns act as outriggers and reduce the overturning moment in the core, and the installed dampers also reduce the moment and the lateral deflection of the structure. This innovative system can eliminate inner beams and inner columns on each floor, and thereby provide buildings with column-free floor space even in highly seismic regions. [14] [15]

Earthquake architecture

The term 'seismic architecture' or 'earthquake architecture' was first introduced in 1985 by Robert Reitherman. [16] The phrase “earthquake architecture” is used to describe a degree of architectural expression of earthquake resistance or implication of architectural configuration, form or style in earthquake resistance. It is also used to describe buildings in which seismic design considerations impacted its architecture. It may be considered a new aesthetic approach in designing structures in seismic prone areas. [17]

History

An article in Scientific American from May 1884, "Buildings that Resist Earthquakes" described early engineering efforts such as Shōsōin. [18]

See also

Related Research Articles

<span class="mw-page-title-main">Curtain wall (architecture)</span> Outer non-structural walls of a building

A curtain wall is an exterior covering of a building in which the outer walls are non-structural, instead serving to protect the interior of the building from the elements. Because the curtain wall façade carries no structural load beyond its own dead load weight, it can be made of lightweight materials. The wall transfers lateral wind loads upon it to the main building structure through connections at floors or columns of the building.

<span class="mw-page-title-main">Seismic retrofit</span> Modification of existing structures to make them more resistant to seismic activity

Seismic retrofitting is the modification of existing structures to make them more resistant to seismic activity, ground motion, or soil failure due to earthquakes. With better understanding of seismic demand on structures and with recent experiences with large earthquakes near urban centers, the need of seismic retrofitting is well acknowledged. Prior to the introduction of modern seismic codes in the late 1960s for developed countries and late 1970s for many other parts of the world, many structures were designed without adequate detailing and reinforcement for seismic protection. In view of the imminent problem, various research work has been carried out. State-of-the-art technical guidelines for seismic assessment, retrofit and rehabilitation have been published around the world – such as the ASCE-SEI 41 and the New Zealand Society for Earthquake Engineering (NZSEE)'s guidelines. These codes must be regularly updated; the 1994 Northridge earthquake brought to light the brittleness of welded steel frames, for example.

<span class="mw-page-title-main">Shear wall</span> A wall intended to withstand the lateral load

In structural engineering, a shear wall is a two-dimensional vertical element of a system that is designed to resist in-plane lateral forces, typically wind and seismic loads.

A tie, strap, tie rod, eyebar, guy-wire, suspension cables, or wire ropes, are examples of linear structural components designed to resist tension. It is the opposite of a strut or column, which is designed to resist compression. Ties may be made of any tension resisting material.

Earthquake engineering is an interdisciplinary branch of engineering that designs and analyzes structures, such as buildings and bridges, with earthquakes in mind. Its overall goal is to make such structures more resistant to earthquakes. An earthquake engineer aims to construct structures that will not be damaged in minor shaking and will avoid serious damage or collapse in a major earthquake. A properly engineered structure does not necessarily have to be extremely strong or expensive. It has to be properly designed to withstand the seismic effects while sustaining an acceptable level of damage.

<span class="mw-page-title-main">Precast concrete</span> Construction material

Precast concrete is a construction product produced by casting concrete in a reusable mold or "form" which is then cured in a controlled environment, transported to the construction site and maneuvered into place; examples include precast beams, and wall panels for tilt up construction. In contrast, cast-in-place concrete is poured into site-specific forms and cured on site.

This is an alphabetical list of articles pertaining specifically to structural engineering. For a broad overview of engineering, please see List of engineering topics. For biographies please see List of engineers.

<span class="mw-page-title-main">Seismic base isolation</span> Means of protecting a structure against earthquake

Seismic base isolation, also known as base isolation, or base isolation system, is one of the most popular means of protecting a structure against earthquake forces. It is a collection of structural elements which should substantially decouple a superstructure from its substructure that is in turn resting on the shaking ground, thus protecting a building or non-building structure's integrity.

<span class="mw-page-title-main">Steel plate shear wall</span>

A steel plate shear wall (SPSW) consists of steel infill plates bounded by boundary elements.

<span class="mw-page-title-main">National Center for Research on Earthquake Engineering</span> Research center in Daan, Taipei, Taiwan

National Center for Research on Earthquake Engineering is an organisation in Da'an District, Taipei, Taiwan.

Studcast concrete, also called "pre-framed concrete", combines relatively thin concrete layers with cold formed steel framing to create hybrid panels; the result is a panelized system usable for cladding, curtain walls, shaft walls, and load-bearing exterior and interior walls. Studcast panels install in the same manner as prefabricated steel stud panels. The technology is applicable for both factory prefabrication and site-cast (tilt-up) wall construction on almost all types of buildings, including multifamily housing, schools, industrial, commercial and institutional structures.

A buckling-restrained brace (BRB) is a structural brace in a building, designed to allow the building to withstand cyclical lateral loadings, typically earthquake-induced loading. It consists of a slender steel core, a concrete casing designed to continuously support the core and prevent buckling under axial compression, and an interface region that prevents undesired interactions between the two. Braced frames that use BRBs – known as buckling-restrained braced frames, or BRBFs – have significant advantages over typical braced frames.

Mete Avni Sözen was Kettelhut Distinguished Professor of Structural Engineering at Purdue University, Indiana, United States from 1992 to 2018.

<span class="mw-page-title-main">Hybrid masonry</span>

Hybrid masonry is a new type of building system that uses engineered, reinforced masonry to brace frame structures. Typically, hybrid masonry is implemented with concrete masonry panels used to brace steel frame structures. The basic concept is to attach a reinforced concrete masonry panel to a structural steel frame such that some combination of gravity forces, story shears and overturning moments can be transferred to the masonry. The structural engineer can choose from three different types of hybrid masonry and two different reinforcement anchorage types. In conventional steel frame building systems, the vertical force resisting steel frame system is supported in the lateral direction by steel bracing or an equivalent system. When the architectural plans call for concrete masonry walls to be placed within the frame, extra labor is required to ensure the masonry fits around the steel frame. Usually, this placement does not take advantage of the structural properties of the masonry panels. In hybrid masonry, the masonry panels take the place of conventional steel bracing, utilizing the structural properties of reinforced concrete masonry walls.

Moment-resisting frame is a rectilinear assemblage of beams and columns, with the beams rigidly connected to the columns.

Ivan Lyall Holmes was a New Zealand structural engineer whose advances in concrete masonry building methods in the 1950s and 1960s were central to the avant-garde style of modernist architecture known as New Brutalism which emerged in the 1950s. It was epitomised locally in the work of architects such as Miles Warren, Maurice Mahoney and Paul Pascoe.

<span class="mw-page-title-main">Nigel Priestley</span> New Zealand earthquake engineer

Michael John Nigel Priestley was a New Zealand earthquake engineer. He made significant contributions to the design and retrofit of concrete structures, and developed the first displacement-based method of seismic design.

<span class="mw-page-title-main">Infill wall</span>

The infill wall is the supported wall that closes the perimeter of a building constructed with a three-dimensional framework structure. Therefore, the structural frame ensures the bearing function, whereas the infill wall serves to separate inner and outer space, filling up the boxes of the outer frames. The infill wall has the unique static function to bear its own weight. The infill wall is an external vertical opaque type of closure. With respect to other categories of wall, the infill wall differs from the partition that serves to separate two interior spaces, yet also non-load bearing, and from the load bearing wall. The latter performs the same functions of the infill wall, hygro-thermically and acoustically, but performs static functions too.

<span class="mw-page-title-main">Medhat Haroun</span> Egyptian-American expert on earthquake engineering

Medhat Haroun was an Egyptian-American expert on earthquake engineering. He wrote more than 300 technical papers and received the Charles Martin Duke Lifeline Earthquake Engineering Award (2006) and the Walter Huber Civil Engineering Research Prize (1992) from the American Society of Civil Engineers.

This glossary of structural engineering terms pertains specifically to structural engineering and its sub-disciplines. Please see glossary of engineering for a broad overview of the major concepts of engineering.

References

  1. Seismology Committee (1999). Recommended Lateral Force Requirements and Commentary. Structural Engineers Association of California.
  2. "Precast New Zealand Inc: Precast concrete and seismic issues". Archived from the original on 2019-08-21. Retrieved 2015-05-18.
  3. "Precast concrete panel building damage, comparing the performance of precast frame-panel (collapsed in foreground) and precast panel buildings (standing in background)". www.eeri.org.
  4. "Earthquake shelter with bed support and canopy".
  5. "Japan, U.S. To Collaborate on Disaster Prevention Research | All American Patriots: Politics, economy, health, environment, energy and technology". Archived from the original on 2011-09-27. Retrieved 2009-06-18.
  6. neesit (17 November 2007). "Shaking Table Test on Conventional Wooden House (1)" via YouTube.[ dead YouTube link ]
  7. "Planning Division - City of Glendale, CA" (PDF). www.ci.glendale.ca.us.[ permanent dead link ]
  8. Kharrazi, M.H.K., 2005, "Rational Method for Analysis and Design of Steel Plate Walls," Ph.D. Dissertation, University of British Columbia, Vancouver, Canada,
  9. Reitherman, Robert (2012). Earthquakes and Engineers: An International History. Reston, VA: ASCE Press. pp. 356–357. ISBN   9780784410714. Archived from the original on 2012-07-26.
  10. "Profits shaken at Tepco". World Nuclear News. 31 July 2007. Archived from the original on 30 September 2007. Retrieved 2007-08-01.
  11. Asahi.com. Quake exposes nuke-plant danger. July 18, 2007.
  12. "Rensselaer Polytechnic Institute News & Events". 12 October 2007. Archived from the original on 12 October 2007.
  13. "Home - Standing Strong: 2009 NEESWood Capstone Test". www.nsf.gov.
  14. "A Survey on concepts of design and executing of Superframe RC Earthquake proof Structures" (2016) by Kiarash Khodabakhshi ISBN   9783668208704
  15. "Seismic Design of a Super Frame" (PDF). Kajima Corporation. Retrieved 27 October 2017.
  16. Reitherman, Robert (August 2–3, 1985). Ten Principles of Nonstructural Seismic Design. Designing for Earthquakes in the Western Mountain States: An AIA Workshop for Architects and Related Building Professionals. Salt Lake City, UT.
  17. Llunji, Mentor (2016). Seismic Architecture - The architecture of earthquake resistant structures. Msproject. ISBN   9789940979409.
  18. Scientific American. Munn & Company. 1884-05-31. p. 340.