Anti-leakage treatment method for deep foundation pit excavation in water-rich silt stratum

Abstract

The invention provides an anti-leakage treatment method for deep foundation pit excavation in a water-rich silt stratum. The treatment method comprises the following specific steps that firstly, WSS slurry injection is adopted at the joint position of a continuous wall outside a foundation pit, then dewatering wells are arranged outside the foundation pit to reduce water pressure, a water pump isplaced in each dewatering well, manual exploration and excavation are started from second-layer earth excavation in the deep foundation pit, a Luoyang shovel is adopted for exploration and excavationto explore the water leakage situation of the joint positions of the underground continuous wall at the underground wall joints, and plugging measures are taken according to the water leakage situation; and after it is confirmed that all underground continuous wall joints of a manual exploration and excavation bin section are free of the water leakage situation, a slurry injection platform is arranged beside the foundation pit, meanwhile, multiple sand backfill windows are formed in the outer side of the foundation pit, and in the mechanical excavation process of the foundation pit, emergencytreatment is carried out in a slurry injection and concrete backfill manner under the water seepage condition. According to the method, the risk of water gushing and sand gushing is avoided, the effect that the subway deep foundation pit is rapidly and stably excavated to expose the bottom is achieved, the construction period is shortened, and the cost is saved.

Description

technical field [0001] The invention belongs to the field of foundation pit construction, and in particular relates to an anti-leakage treatment method for excavating deep foundation pits in water-rich silt sand formations. Background technique [0002] The subway can quickly, safely and comfortably transport a large number of passengers, and has good social and economic benefits. Therefore, in recent years, the construction of urban subways has developed rapidly. However, since the subway construction is carried out underground, the underground structure is greatly affected by the hydrogeological environment, and there is a huge construction safety risk in the construction process of the subway civil engineering, which is easily affected by the seepage of the underground enclosure structure, especially when the enclosure When the protective structure is an underground diaphragm wall, the hidden danger of water seepage at its joints is even greater. [0003] At present, in ...

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Problems solved by technology

[0004] Most of the existing anti-seepage and plugging constructions of foundation pits adopt the method of grouting from the ground hole, and the size of the hole hole equipment and the grouting equipment is relatively large. Insufficient, and the cement-sodium silicate slurry used in the grouting process stays in the grouting pipeline for a long time, which is prone to pipe plugging, which will not only affect the effect of leak prevention and plugging, but also affect the excavation of the foundation pit Construction Schedule

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