The main purpose of foundation pit reinforcement is to reduce the displacement of retaining structure, improve the strength and lateral force of soil, prevent the uplift and destruction of soil at the bottom of the pit, and make up for the lack of insertion depth of retaining wall.

Features:

1 can improve the mechanical properties of soft foundation soil, ensure the stability of soil during foundation pit excavation, and be beneficial to the reinforcement of soil in foundation pit.

2. The surrounding environment and facilities are maintained, and the lateral displacement of the foundation pit is stopped. The reinforcement of "middle beam in place first" in the pit can greatly improve the lateral force of soil in passive area and reduce the probability of unloading deformation of foundation pit.

3. For the old buildings that need to be rebuilt, the problem of insufficient buried depth of the original enclosure layout can be solved, and the safety and stability of foundation pit excavation can be ensured through the reinforcement measures in the pit.

4. When excavating, it can isolate the influence of groundwater, stabilize the pit bottom, and facilitate the pit bottom reinforcement and waterproof curtain.

5. For the confined water layer, the confined water can be resisted by reasonable soil reinforcement forms to ensure the stability of the soil at the bottom of the pit.

Methods and key points of soil reinforcement technology in foundation pit construction;

1, grouting reinforcement method:

Grouting reinforcement technology has been used for a long time. Grouting means that grout with filling and cementation functions is injected into soil particle gaps, soil interface and rock cracks in the stratum through pressure conveying equipment, and the grout will disperse, gel or solidify, forming a new soil with high strength and chemical stability.

In foundation pit, the advantages of grouting reinforcement technology are: it can reduce the horizontal displacement of retaining wall; Improve the anti-floating stability at the bottom of the pit; Effectively control the deformation of foundation pit; Effectively stop water and prevent leakage; Grouting permeates and fills deformation cracks, etc.

2, precipitation reinforcement method:

In foundation pit construction, dewatering reinforcement method is one of the most commonly used and economical treatment methods to reinforce the soil in the pit, thus improving the soil properties and greatly increasing the lateral resistance of the soil in the passive area.

Dewatering method is often used to reinforce the unilateral sandy soil layer at the bottom of foundation pit. Its disadvantage is that it has little improvement on soil properties and is not suitable for soft soil areas with high requirements on manipulation and deformation.