Pump station foundation pit integrated drainage system and construction method

Abstract

The invention provides a pump station foundation pit integrated drainage system. The system is characterized in that a circle of cement soil seepage interception wall is arranged outwards at intervals along the outer side line of a foundation pit to form a closed seepage interception wall body, the cement soil seepage interception wall penetrates through a permeable layer, and the bottom of the cement soil seepage interception wall extends to the position 2 m below a relative impervious layer; on the outer side of the foundation pit with the closed space formed by the cement soil seepage interception wall, a circle of out-pit pressure reduction wells is constructed outwards along the cement soil seepage interception wall, and the bottom elevation of the pressure reduction wells is located at the bottom elevation of the permeable layer; an in-pit drainage well is constructed in the foundation pit, and the bottom elevation of the drainage well is located at the bottom elevation of the permeable layer; and the pump station foundation pit integrated drainage system is jointly formed by the cement soil seepage interception walls, the out-pit pressure reduction wells and the pit interior drainage well, a closed seepage interception wall is formed by the cement soil seepage interception walls, the underground water level in a foundation pit is reduced to be 0.5 m or below of a design base through the drainage drainage well, and the water head difference between the interior and the exterior of the foundation pit is kept within the range of 7 m through the drainage pressure reduction well. The dewatering and drainage requirements of the foundation pit of the large pump station can be met, and dry land construction conditions are created.

Description

technical field [0001] The invention relates to the technical field of foundation pit construction of a pumping station, and more specifically relates to an integrated drainage system and a construction method for a foundation pit of a pumping station. Background technique [0002] The foundation pits of large pumping stations have a large range and deep excavation, especially some pumping station foundation pits along the Yangtze River. The foundation soil has a large sand content and abundant groundwater, which forms a supplementary form with the Yangtze River. Precipitation measures must be taken care of before excavation of foundation pits . [0003] The common drainage measures mainly include: open ditch drainage, light well point drainage, tube well drainage, concrete cut-off wall and well point combined drainage, etc. [0004] 1. Open ditch drainage: Open ditch drainage is only suitable for foundation pit drainage with small foundation soil permeability coefficient, ...

AI Technical Summary

Problems solved by technology

However, this method uses concrete cut-off walls, which requires a large amount of work, difficulty in construction and demolition, and high cost

Images