Deep foundation pit floury soil stratum deep-well well point rainfall construction method and application

Abstract

The embodiment of the invention provides a deep foundation pit floury soil stratum deep-well well point rainfall construction method and application, and relates to the field of traffic building and construction. The construction method comprises the steps of drilling a plurality of out-of-pit precipitation wells outside a foundation pit, and drilling a plurality of in-pit precipitation wells in the foundation pit; and lowering a plurality of well pipes to the corresponding out-of-pit precipitation wells and the corresponding in-pit precipitation wells to form corresponding in-pit well pipes and out-of-pit well pipes. By means of the deep foundation pit floury soil stratum deep-well well point rainfall construction method and the application, the out-of-pit precipitation wells and the in-pit precipitation wells are combined for precipitation, and the conditions that when light well points cannot meet the precipitation requirement, the number of the light well points are gradually increased, consequently the number of the well points is increased, and the excavation amount is increased are effectively avoided; and in-pit precipitation and out-of-pit precipitation are combined, the groundwater in soil within the foundation pit excavation scope is effectively drained, and construction work of construction machinery and workers in the pit are facilitated.

Description

technical field [0001] The invention relates to the field of traffic construction and construction, in particular to a construction method for dewatering a deep well point in a powdery soil layer of a deep foundation pit and an application thereof. Background technique [0002] During the construction of the traffic road, if the geology of the silty clay stratum is encountered, due to its poor stability, in the excavation project of the deep foundation pit of the subway station, in order to dry the soil in the excavation range of the foundation pit Groundwater, as well as reducing the head height of the lower confined aquifer, ensure the stability of the foundation pit during construction. Traditional drainage methods can no longer meet the requirements of construction. If the dewatering construction cannot be done in time, there will be serious phenomenon of mud turning, mud and quicksand, which will not only make the foundation pit unable to dig deep, but also cause a larg...

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Problems solved by technology

[0002] During the construction of the traffic road, if the geology of the silty clay stratum is encountered, due to its poor stability, in the excavation project of the deep foundation pit of the subway station, in order to dry the soil in the excavation range of the foundation pit groundwater, and reduce the head height of the lower confined aquifer to ensure the stability of the foundation pit during construction. Traditional drainage methods can no longer meet the requirements of construction

If the dewatering construction cannot be done in time, there will be serious phenomenon of mud turning, mud and quicksand, which will not only make the foundation pit unable to dig deep, but also cause a large amount of water and soil loss, causing the slope to become unstable or the nearby ground to collapse. It will also affect the safety of nearby buildings

[0003] In view of the specific geological conditions of the silty clay stratum, when construction is carried out on the silty soil, due to the difficulty of water seepage in the silty soil stratum, light well points are usually used for dewatering during construction. One light well point to achieve multi-point synchronous dewatering, but if you want to meet the preset dewatering requirements, you need to set up many light well points, and the layout of light well points is scattered, which will greatly hinder the construction in the pit. At the same time, when the number of light well points is too large, it is necessary to set up a pump for each light well point and observe the pumping situation of each light well point, which will undoubtedly increase the equipment cost and labor cost

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