What are the adaptation areas of the preloading method?

The pre-pressing method is suitable for the treatment of saturated clay foundations such as silt soil, silt and flushing soil. Generally, when the thickness of the soft soil layer is less than 4m, the natural foundation preloading method can be used. When the thickness of the soft soil layer exceeds 4m, in order to accelerate the preloading process, vertical drainage preloading such as plastic drainage belts and sand wells should be adopted. The law handles the foundation. 

For vacuum preloading, vertical drains must be placed in the foundation.