lesson 9/10: building standards

Question 1

base isolation

Answer 1

The building is positioned on something which allows it to be isolated from the ground when the earthquake occurs. It allows the building to move independently of the ground shaking beneath it. There is a moat around the building and of course all connections such as electricity have to be flexible. Separating buildings from the ground. To do this you have to put buildings on some kind of springs or bearings which allow the building to move independently to the ground beneath during an earthquake. In order to do this all buildings have to separate from each other and there has to be space between buildings to allow them to move independently. In addition all services like electricity, gas, water, sewage and cable have to be connected to the house via flexible cables so that they don’t snap in an earthquake.

Question 2

dampers

Answer 2

act like shock absorbers. They absorb or dissipate some of the seismic energy, therefore dampening the motion of the building. These can also take the form of weights placed in or on a building. When the building sways, the damper sways in the opposite direction to offset the movement. These are large weights e.g. water tank or metal/concrete ball that are placed at the top of tall buildings. When an earthquake strikes large buildings start to sway. The dampers swing in the opposite direction to the building to reduce sway. Dampers also stop buildings sway excessively in high winds. However, tall buildings do need to be able to sway slightly, if they can’t then they are too rigid and will collapse in a quake.

Question 3

cross bracing

Answer 3

made of strong and flexible metal. This bracing makes the building stronger and able to withstand the shaking motion. These are basically metal reinforcements placed throughout buildings to give them more strength during ground shaking experienced in an earthquake.

Question 4

outrigging

Answer 4

rigid horizontal structures designed to improve building strength by connecting the building core or spine to distant columns. This helps to support the building as it sways. This design principal has been used for millennia for example in outrigger canoes.