This earthquake has set back San Francisco development a lest 10 years. Causing over three thousand death and near two hundred twenty five thousand injuries. The total destruction cost of this earthquake was over 400 million dollars.The design of current buildings in California is highly complicated. Current laws state that new building built in earthquake zone must have up to date earthquake design. There are many types of earthquake design in the bay are. There is new technology that people are using like seismic isolation, which is the building sit on top of huge rubber bearing with steel sheets. Those rubber bearings are connected to the ground and the building. When the building is involved in a earthquake the rubber bearing act as dampeners and allow the building to move with they earthquake The most commonly used and cost effective is the lateral load resting system. These systems are shear wall, braced frame, moment resisting frame, diaphragm. Diaphragms Figure 1: Horizontal Diaphragm Action Diaphragms are horizontal resistance elements, generally floors and roofs, which transfer the lateral forces between the vertical resistance elements (shear walls or frames). Basically, a diaphragm acts as a horizontal I-beam. That is, the diaphragm itself acts as the web of the beam and its edges act as flanges. Shear Walls Shear walls are vertical walls that are designed to receive lateral forces from diaphragms and transmit them to the ground. The forces in these walls are predominantly shear forces in which the fibers within the wall try to slide past one another. When you build a house of cards, you design a shear wall structure, and you soon learn that sufficient card "walls" must be placed at right angles to one another or the house will collapse. Figure 2: Shear Walls If you were to connect your walls together with tape, it is easy to see that the strength of this house of cards would be immediately become greatly increased. This...
