Super pressure and suction combined well point dewatering construction method of deep foundation pit of metro

Abstract

The invention relates to the field of building construction, and discloses a super pressure and suction combined well point dewatering construction method of a deep foundation pit of a metro. The method comprises: (1) staking out in survey; (2) middle measurement and leveling; (3) hole drilling; (4) a well descending pipe and water filter pipe; (5) filling back gravels; (6) well sealing: cement paste is injected in a well through a grouting pipe; (7) well washing: compressed air is introduced to the lower portion of a drainage pipe by an air compressor through an intake pipe, so that mud outside the drainage pipe flows into the drainage pipe under the effect of an internal and external pressure difference of the drainage pipe and is taken outside the well by the drainage pipe; and when water drained from the drainage pipe meets designed well washing quality requirements, well washing is finished; (8) trial water pumping: a pump is put in for trial pumping, and the well completion is finished if the trial pumping is successful; and (9) formal dewatering: the water in a dewatering well is pumped into a drainage ditch of the top of the foundation pit by a super pressure and suction combined water pumping system. The method realizes quick and effective dewatering of the deep foundation pit so as to meet the dewatering demand in the deep foundation pit engineering.

Description

technical field [0001] The invention relates to the technical field of building construction, in particular to a super pressure-suction combined well point dewatering construction method for subway deep foundation pits. Background technique [0002] With the needs of urban development and the maturity of subway construction technology, subway has been widely used in cities. The excavation depth of subway deep foundation pits generally ranges from 20m to 30m, and the groundwater level is higher than the excavation bottom surface. If the precipitation is not timely, groundwater will continue to seep into the pit, which will cause slope instability, foundation quicksand, pit bottom uplift, pit bottom piping and Decreased bearing capacity of the foundation, etc. In order to prevent possible dangers of surge, quicksand, and uplift, reduce the confined water level, reduce pressure, and ensure the safety of foundation pit excavation, it is generally necessary to take corresponding...

AI Technical Summary

Problems solved by technology

[0003] In actual construction, steel sheet piles, cement mixing piles or water cut-off curtains are often used to control groundwater before excavation of foundation pits. limited engineering role

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