The elements are contained in layers of mud ranging in thickness from 2 meters to 70 meters that have accumulated on seabeds 3, 500 meters to 6, 000 meters deep.

The soft soil refers to the soft clay deposited under water or mud-based formation, sometimes with a small amount of rot folder mud or peat layer.

It profoundly mixes materials such as silt, silty soil, clay and sub-clay through deep mixer, which takes cement as solidify agent, hence greatly improves bearing capability of groundsill.