Structures That Are Earthquake Resistant
The Sidekick
From a simplistic standpoint, an earthquake places a sideways load on a building. So in order to make a bridge, building or other structure, required to hold up forces of gravity that is related to the weight of the structure and what is inside, an earthquake resistant structure can weather a considerable sideways force, this is usually done by tying the walls, floor, roof and foundations into a rigid box.
Masonry Woes
The worst building, from an earthquake point of view, is made of non-reinforced masonry such as brick or concrete blocks. The walls are usually made of bricks that are stacked and held together with mortar. The roof is then made of beams of wood or steel applied around the top of the wall. The weight of the roof is barring straight down on the foundation walls. When a sideways jolt is applied to this type of building, the masonry walls tip over or crumble and the roof falls in on the occupants like a stack of cards. Since this type of structure is prevalent in poorer countries, the death toll from earthquakes can be many times higher than in places with strict building codes such as Japan or California.
Fundamentally Strong Foundation
As the buildings increases to a bigger and taller, the challenge grows more complex. The harmonic characteristic of the building and ground have to be considered. For instance, even if the building is very strong, the foundation will began to settle which leads to sinking and tipping over. A good example is the 1964 earthquake inin Nigata, Japan. The Kawagushi-cho apartment buildings toppled over like a series of dominoes. The buildings themselves were super strong and remained intact but their foundations failed to counter the quake. Only 28 people were killed even though 2000 homes were destroyed. Therefore building codes without a doubt conserved many lives.