Construction method of dewatering well under foundation slab in foundation pit

Abstract

The invention discloses a construction method of a dewatering well under a foundation slab in a foundation pit, comprising the following steps of: arranging the dewatering well in the foundation pit, wherein the dewatering well is not damaged in the process of excavating a foundation pit earthwork, and the effectiveness of the dewatering well is ensured; after the foundation pit earthwork is excavated to a basement, excavating interlaced ditches along the center line of the dewatering well, and paving water-filtering type geotextile in the ditches; then paving drain pipes of the dewatering well and cables in the ditches and connecting to the outside of the pit, checking the depth of the dewatering well, an extraction pump and a pipeline thereof to ensure the integrality and the reliability; then paving granular crushed stones or cobbles in the ditches, covering asphalt felt thereon to form a blind ditch; leading the blind ditch to a water collection pit at the edge of the foundation pit and arranging a surface drain on the periphery of the foundation pit; paving a subcrust and a waterproof layer under the constructed foundation slab, gradually reducing the usage quantity and the dewatering speed of dewatering wells in the foundation pit in the construction process of underground structures and upper structures thereof, and assisting in draining by adopting the water collection pit at the periphery of the foundation pit until the dewatering operation in the foundation pit can be stopped. The invention has convenient construction, safety and reliability and low cost for dewatering in the foundation pit.

Description

Technical field: [0001] The invention relates to a construction method for a foundation floor descending well in a foundation pit. Background technique: [0002] With the rapid development of the development and utilization of underground space, ultra-deep and ultra-wide foundation pit projects are constantly emerging. The drainage measures and their reliable effects in ultra-large deep foundation pits rich in groundwater, especially affected by underground confined water, are the key to ensure deep It is one of the important construction measures to ensure the safety of foundation pit operation and ensure the quality of the project. The general dewatering method is to arrange multiple dewatering wells in the foundation pit. The downwater pipe and its cable line pass through the foundation structure through the casing and other corresponding waterproof treatment measures, and are discharged outside the foundation pit. After meeting the requirements for stopping dewatering, t...

AI Technical Summary

Problems solved by technology

The general dewatering method is to arrange multiple dewatering wells in the foundation pit. The downwater pipe and its cable line pass through the foundation structure through the casing and other corresponding waterproof treatment measures, and are discharged outside the foundation pit. After meeting the requirements for stopping dewatering, the dewatering The foundation structure casing that the well passes through is waterproofed and rigidly sealed; this dewatering construction method, although meeting the dewatering requirements of deep foundation pit operations, affects the waterproof construction quality of the foundation structure, even if the waterproof effect of the casing can be guaranteed, but The guarantee of its waterproof effect depends only on the waterproof effect of the single foundation structure concrete itself, and the coiled material or paint waterproof layer under the foundation structure has been destroyed. Meet the corresponding underground engineering waterproof standards or specification requirements

During the construction of some deep foundation pits, in order to avoid the waterproof node treatment at the dewatering wells on the above-mentioned foundation structure, the dewatering wells are arranged around the foundation pit, which greatly increases the depth of the dewatering wells, the dewatering time and the dewatering range. Precipitation costs, and at the same time, the adverse impact on the surrounding environment outside the foundation pit is greatly increased

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