Earthquakes and how to build to counter their effects
- Seismic waves
- Three different kinds of earthquakes
- Documenting the seismic performance
- 1933 Long Beach earthquake in California
Earthquakes can cause a great amount of damage to cities and towns which find themselves in the path of an earthquake. Despite this, towns and cities are still built near fault lines where earthquakes are a common occurrence. To combat the earthquakes which attempt to turn these structures into rubble, buildings are being built in special ways to limit the amount of damage caused by the rampaging earthquakes. I plan on giving a glimpse at how these earthquake-proof and earthquake-resistant buildings are designed.
Firstly, it is important to understand how earthquakes originate and how they cause damage. An earthquake is caused by stress, usually along fault lines. Fault lines exist near plate boundaries, owing to which, most earthquakes occur along these boundaries. Stress builds up along the fault line, until too much stress builds up. The stress then causes the sides of the plates to slip. A slip is the displacement of adjacent points on opposite sides of a fault. When a slip occurs, it tends not to slip very far (the maximum slip recording being only a twelve meter displacement), but the seismic waves created by the sudden release of energy the slip produces can cause damage.
[...] A building is graded on its seismic performance, which is the building's ability to maintain safely and use, during and after an earthquake. Safe in this context means that it does not harm the lives of those within, or around it whether such damage would be done through falling bricks or the entire complex falling apart. Use implies that the building will be able to fulfill its functions after an earthquake. Earthquake engineering is based very strongly in building codes. [...]
[...] Ductility is the property of metal which permits it to be reduced in cross sectional area without fracture. This helps the steel be able to keep itself strong and so it is able to keep its role as reinforcement for the rest of the structure. Earthquake engineering is essential in order to keep communities and structures intact when an earthquake strikes. By understanding how earthquakes damage manmade structures, engineers can learn how to formulate plans and rules which force people to build buildings which can fight against these earthquakes. It also allows [...]
[...] CBC News had an article about the recent earthquake in Haiti that showed a bit of the damage such earthquakes can cause, last major earthquake in the region happened in 1946 and was a magnitude It triggered a tsunami and left 20,000 people homeless, according to the U.S. Geological Survey?, Haiti's quake was so devastating?, CBC News). The earthquake in Haiti which occurred on January affected an estimated three million people. The Haitian Government reported that between 217,000 and 230,000 died, as well as 300,000 injured, and an estimated one million people were left homeless. [...]