Earthquakes are one of the Earth’s most destructive forces – the seismic waves (shockwaves throughout the ground in short rapid intervals in all different directions) can destroy buildings, take lives, and costs tremendous amounts of money for loss and repair. The damage is not caused by the quake itself but by the collapse of buildings with people inside them, making earthquake-resistant buildings a must.
Buildings are basically designed to support a vertical load in order to support the walls, roof and all the stuff inside to keep them standing. Earthquakes present a lateral, or sideways, load to the building structure. One way to to make a structure more resistant to these lateral forces is to tie the walls, floor, roof, and foundations into a rigid box that holds together when shaken by a quake. That is exactly what we did when designing the NxtGen Houses earthquake resistant structure.
Steel and Wood
For a building material to resist stress and vibration, it must have high ductility — the ability to undergo large deformations and tension. Our buildings are often constructed with structural steel – a component of steel that comes in a variety of shapes that allow buildings to bend without breaking. Wood is also a surprising ductile material due to its high strength relative to its lightweight structure.
Create a Flexible Foundation
Another way to resist ground forces is to “lift” the building’s foundation above the earth. We use screw anchor piles for deep foundation. Base isolation involves constructing a building on top of flexible pads made of steel, rubber, and lead on top of the anchor piles when necessary in area’s with high earthquake possibility. When the base moves during the earthquake, the isolators vibrate while the structure itself remains steady. This effectively helps to absorb seismic waves and prevent them from traveling through a building.
Reinforce the Building’s Structure
Shear walls, cross braces, diaphragms, and moment-resisting frames are central to reinforcing a building. Shear walls are often supported by diagonal cross braces. These steel beams have the ability to support compression and tension, which helps to counteract the pressure and push forces back to the foundation.