Earthquake Resistant Building Pdf

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Aftera large earthquake, the news inundates us with images of crumbled concrete, twisted steel, and disaster recovery teams searching through rubble for survivors. According to the California Department of Conservation, the 1989 Loma Prieta earthquake caused 63 deaths, and 3,757 people reported injuries from the disaster. The World Health Organization says that earthquakes caused nearly 750,000 deaths worldwide between 1998 and 2017. And more than 125 million people were affected, either through injuries or displacement.

Though earthquakes are uncontrollable, earthquake damage to people and property is predictable and preventable with earthquake engineering and earthquake-resistant building technology. While an earthquake-proof building is impossible, at least for the foreseeable future, earthquake resistance is possible with a holistic, cohesive approach.

In earthquakes, some of the damage is immediate, catastrophic, and obvious. Other damage can be more insidious. For example, seismic vibration could separate roof flashing, the material that directs water away from vulnerable connection points in the roof. Then water can enter the structure (sometimes unnoticed) and cause damage later.

Methods for making a structure earthquake-resistant involve either deflecting, absorbing, transferring, or distributing vibrations from seismic activity. Those methods come into play with building design. A more holistic, proactive approach is seismic design. This process analyzes both the site and the surrounding area before building design begins.

All these considerations help establish priorities and inform which seismic resistance techniques to use. This holistic approach has the added benefit of hardening buildings against other threats, from terrorism to high-speed winds.

Making buildings resistant to earthquakes begins with the soil beneath it. Soft, silty soils are prone to liquefaction during earthquakes. Liquefaction is when soil temporarily behaves like a liquid. Soft soils can also amplify vibrations. Any structure on such soil is at risk. An earthquake-resistant building is best located on solid ground.

Earthquake-resistance techniques can be used throughout a building, from foundation to roof and exterior to interior. The specific technique depends on the type of vibration control ideal for that location.

Seismic dampers can be used throughout the foundation and structure to absorb vibrations from earthquake forces. Dampers come in a variety of forms. For example, viscous dampers use hydraulics to dissipate energy. A tuned mass damper uses weight at the top of or at critical points throughout a structure to counteract ground motion. Friction dampers are like the brakes in most cars, converting movement to heat.

Structural reinforcements transfer or distribute vibrations to decrease their impact. For example, shear walls transfer vibrations to the foundation. Floors and roofs built as diaphragms distribute vibrations across the horizontal structure and into stronger vertical structures. Moment-resistant frames help connection points remain secure while allowing columns and beams to move without damage.

Nonstructural elements of the building can also cause significant injuries during an earthquake. In fact, a study in New Zealand showed that while failed structural elements caused the most fatalities, damaged nonstructural elements caused exponentially more injuries. The elements that caused the most injuries were furniture, shelving, suspended ceilings, and HVAC equipment and ducting.

The Federal Emergency Management Agency published an extensive guide on reducing risks of nonstructural earthquake damage. And cities in active seismic zones often have seismic building codes that address bracing guidelines for nonstructural elements.

Masonry and concrete have the lowest ductility. Unfortunately, many buildings erected prior to the 1950s used exactly those materials. Reinforcing or wrapping masonry and concrete can make such foundations and structures strong in an earthquake, which new materials are making increasingly possible.

Scientists and engineers are developing new building materials for earthquake-resistant construction. These materials range from shape-memory alloys to invisibility cloaks to fibers created from synthetic spider silk.

Spider silk is highly elastic yet stronger than steel. Its synthetic cousin displays similar properties, and manufacturers are racing to perfect it. The exact application in construction is yet to be determined. Theoretical construction-related applications include power grids, data networks, building cladding, scaffolding, and frames.

New technology plays an important role in expanding our understanding of earthquakes and developing creative solutions to build earthquake-resistant structures. Seismic retrofitting, seismic analysis, and seismic sensors are aspects of this process.

This issue is about more than foundations, walls, and roofs. Consider utility lines (power, data, water, and gas) and how they might be impacted by an earthquake. If a building shifts, gas lines may separate and break, typically at connection points, but gas will continue to flow and fill the space. People in the space are then in danger of inhaling the gas, or the gas could ignite. Retrofitting gas lines may require multiple methods for maximum safety, including gas shut-off valves and flexible connections.

Structural engineers use seismic analysis in earthquake engineering to predict how a structure will perform during seismic activity. While seismic building codes may specify which type of analysis is required in particular zones, engineers use a variety of models for full assessments.

Available models include equivalent static analysis, response spectrum analysis, linear dynamic analysis, nonlinear static analysis, and nonlinear dynamic analysis. Each type of analysis uses computer modeling for the complex calculations. With adequate seismic sensor data, artificial intelligence and machine learning can identify risks, structural faults, and even subtle fault lines that humans cannot.

Edge computing, as opposed to cloud computing, brings data processing and storage physically closer to users to increase speed and decrease bandwidth use. The edge ecosystem requires robust, reliable internet service, as does sending out alerts and coordinating disaster recovery after an earthquake.

Earthquake resistance requires a holistic, cohesive approach that uses the latest trends in technology on multiple fronts. Earthquake-resistant building technology, seismic monitoring, early-warning systems, and natural disaster response all exist in the same system and should be treated accordingly. This approach will save lives and protect property.

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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]

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]

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]

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]

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.

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