Earthquake-proof buildings in ancient cultures

Tuesday, August 16, 2011

Earthquakes are caused by waves produced when the rocks deep within the earth move. The energy that is released travels through the earth. The amount of damage done by an earthquake depends on the strength of the waves and the design of the building.

People in ancient cultures who lived in earthquake areas built earthquake-resistant buildings. In Buddhist pagodas in Japan the cen­tral shaft is sunk into the ground. Flexible joints attach the roof sections to the central shaft. The shaft sways during an earthquake, but the roof doesn't fall.

Chínese architects designed tentlike structures. Each building had a sloping, tiled roof. A central wooden beam supported the length of the roof. Each end of the beam had vertical shafts driven deep into rock. Lightweight bamboo walls hung from the roof, almost like curtains. The walls absorbed energy by swaying, since they were supported by the roof and not by the ground.

In the American Southwest and in Central America, adobe buildings remain standing after numerous earthquakes. Adobe walls are made of clay bricks with a crisscross network of twigs. This construction gives flexibility to each wall. The walls absorb the energy of earthquake waves to remain standing.

What is a depressant?

A depressant is a drug that reduces the activity of various body functions. Some depressants such as anesthetics, sedatives, antiepileptics, narcotics analgesics, and some muscle relaxants, slow nervous and muscular activity by acting on the central nervous system. Tranquilizers are depressants that affect only part of the nervous system. They induce relaxation without causing total depression.

Facts about birthstones

Facts about birthstones
Did you know? The current assignation of stones to months was established in 1912