Numerous researches confirmed that the nature of the soil directly affects the size of the damage caused by earthquakes. Research indicates that earthquake risk in hard rocky soils is lower, in contrast to waterlogged sandy soils.
Rocky soil is earthquake resistant
Research indicates that rocky soils are stronger in resisting earthquakes than weak soils because, due to the presence of rocks, they have great frictional resistance.
Dry soil is suitable for erecting buildings
With regard to dry or low-moisture soils, it is suitable for establishing buildings and facilities, especially in areas classified as having low seismic activity.
Soil saturated with moisture leads to the collapse of structures
In contrast, the sandy soil saturated with moisture, such as the sandy soil located near the seas, is exposed to earthquakes that may lead to the collapse of the structures built on it.
Soil liquefaction exacerbates the damage
The liquefaction of the soil with the occurrence of earthquakes exacerbates the damage, and the phenomenon of soil liquefaction occurs when the soil loses its hardness as a result of its saturation with water.
The resulting damages include massive property losses, sinking and tilting of buildings, collapsing cliffs, subsidence and cracking of the ground surface.
In view of these damages, experts always advise that all buildings be appropriate to the nature of the soil in order to avoid disasters.
Japan.. a successful model in avoiding earthquake damage?
Japan is famous for the most earthquake-resistant skyscrapers in the world, despite being located at the epicenter of the earthquake belt.
Japan has suffered from earthquakes throughout its history, the worst of which was the Great Kanto Earthquake in 1923. It had a magnitude of 7.9 on the Richter scale, devastating Tokyo and Yokohama, and killing more than 140,000 people.
Since then, Japan has applied strict building standards, most notably a law that specifies requirements for buildings to resist earthquakes, including recommended thicknesses for columns and walls to counteract ground shaking.
And another law for tall buildings recommends the use of dampers that absorb a lot of earthquake energy, so that layers of thick rubber maps are placed on the ground, to greatly absorb tremors.
Japan also imposes a law that is considered the most advanced for earthquake-resistant buildings, and it is also the most expensive. And it has standards for building the structure of the building itself in isolation from the ground, “by layers of lead, steel and rubber that move independently with the ground beneath them when earthquakes occur.
A civil and architectural engineering consultant, Muhammad Badir, said in his interview with “Sky News Arabia”:
- Japan’s turning point with earthquakes was in 1923, after the Kantō earthquake.
- Buildings in Japan take into account the soil on which they are built.
- Soil is a very important factor, and many studies are being conducted on it to reach the best foundation for buildings.
- There was a difference between structural engineers and architects in this field.. because the structural engineer cares about safety and the architect cares about architecture and beauty.
