While high-rise structures will sustain structural damage, the earthquake would cause a protracted period of gradual shaking. Low-rise buildings in earthquake zones, however, may not survive due to their height and proximity of their center of gravity to the shaking. In addition, low-rise buildings are more likely to suffer severe damage from falling objects during an earthquake.
In an earthquake, all large structures are at risk of collapse. However, if you take the right precautions, you can reduce the danger to yourself when a major quake hits. First, make sure that you are in a sturdy building designed to with stand an earthquake. If you are not in a safe building, go there now! Next, check on your family and friends, and stay together as much as possible. Finally, call 911 if needed, but avoid areas where people might be trapped under debris.
When a major earthquake strikes, it can be very frightening. But, with preparation and common sense, you can protect yourself from injury or death. If you're in a high-rise building, stay away from windows until the shaking stops. Drop what you are doing and go to a safe place immediately. Check on those around you, too; some people may not be able to handle the stress of an earthquake alone.
Major earthquakes are rare, but they do happen.
Modern high-rise buildings in low seismicity zones are built to handle lateral loads, particularly wind forces, which can be substantially greater than earthquake forces. High-rises are therefore considered safe places to be during earthquakes.
In addition, people in high rises have access to higher floors, which are usually less damaged by the initial shock and so provide better opportunities for escape. Also, the elevators are often powered by hydraulic systems that function even if power to the building is lost due to destruction of electrical lines or other causes. Finally, fire departments have training and equipment for managing disasters on multiple floors simultaneously.
High rises can also be dangerous places to be during earthquakes: fallen objects, damaged balconies, and broken glass are all potential hazards for those inside the building. In addition, smoke from burning material, water from leaking pipes, and damaged gas lines can lead to serious injury or death if not detected quickly. People who live in high rises should take all necessary precautions to protect themselves from harm caused by seismic activity.
Seismic safety standards require that high-rise buildings be located in areas where they do not pose a threat to public safety. In general, buildings over 10 stories tall are not permitted in areas where local fault lines come within 200 meters of the structure's edge.
The design of any structure, whether high-rise or low-rise, will have a substantial impact on its survivability during an earthquake. High-quality construction and appropriate design measures can reduce the risk of damage due to wind loading.
In addition to considering the effects of wind, a high-rise building's designer should also consider the effect of its own construction: the higher the building, the more likely it is to suffer damage from its own weight. This is called self-weight damage and can result in falling debris, broken windows, and collapsed roofs. The likelihood of this type of damage increases with height because taller structures have more mass over a smaller area. Engineers typically use structural analysis programs to determine if a building is at risk for self-weight damage. If so, they may recommend alternative designs (such as adding another floor), additional strengthening methods (such as using shear walls), or both.
When a high-rise building does experience damage from an earthquake, its occupants need to know that help is on the way. Fire departments have the training and equipment to respond to emergencies in high-rise buildings, so ensure that your building's emergency plan includes information on where to go during an emergency.
It may appear evident that earthquakes do the majority of their damage by shaking the ground. When the earth underneath a structure shakes, the energy of the quake's waves travels through it, causing the building to wobble. If the building is made of solid material, such as stone or concrete, then its weight will try to keep up with the movement of the earth, but if it isn't strong enough, it will collapse.
The way a building responds to an earthquake depends on how well it was designed and built. The type of construction used for a building, such as brick or wood, also affects how much it will shake during an earthquake. An important factor is the distance between floors and ceilings and the quality of any supporting columns. If these elements are not enough to hold up heavy walls, they can create a dangerous situation when the ground starts to shake.
Buildings have three main types of movement: vertical, horizontal and rotational. In most cases, all three types of movement occur together, but they can also be isolated. Vertical movement is when the entire building rises up and falls down with each wave of the earthquake. Horizontal movement is when the building moves back and forth like the tide. Rotational movement is when the whole building turns over side-to-side.
Vertical movement is controlled by the strength of the foundation.