Preparation before earthwork excavation of deep foundation pit

Before the earthwork excavation of deep foundation pit, the excavation scheme and construction organization should be determined in detail; It is necessary to monitor and protect the supporting structure, groundwater level and surrounding environment.

Excavation scheme

The excavation schemes of deep foundation pit mainly include slope excavation (without supporting structure), central island excavation (also known as pier excavation), basin excavation and top-down method. The latter three have supporting structures.

Mining sequence and method

The sequence and method of earthwork excavation must comply with the design conditions, and follow the principle of "slotting support, first support and then excavation, layered excavation, and no overbreak".

Prevent the rebound deformation of soil from being too large.

Prevent excessive rebound deformation of soil after deep foundation pit excavation.

Prevent slope instability

Prevent slope instability.

supporting structure

The supporting forms of deep foundation pit generally include row piles or diaphragm wall, soil nailing wall and deep cement mixing pile as enclosure structure.