Grain shape influences liquefaction of sand, a major earthquake hazard

Source: The post is based on the article “Grain shape influences liquefaction of sand, a major earthquake hazard” published in PIB on 19th July 2022.

What is the News?

Scientists have found that the shape of sand grains influences the liquefaction of sand which is one of the major factors behind the collapse of structures during earthquakes.

What is the Liquefaction of sand?

Liquefaction of sand is a phenomenon in which the strength and stiffness of a soil are reduced by earthquake shaking or other rapid loading and lead to the collapse of structures resting on the liquefied ground.

What have the scientists found in this study?

Scientists have found that the shape of sand grains influences the liquefaction of sand. For instance, natural sand with a regular shape liquefies easily compared to sand with an irregular shape.

This is because the shear force (unaligned forces pushing one part of a body in one specific direction and another part of the body in the opposite direction) required to break the inter-particle locking is more for the grains with relatively irregular shapes. 

Hence, the scientists concluded that natural sand used in structures like slopes and retaining walls can be replaced with irregular manufactured sand to improve stability and sustainability.