Waterproof casing pipe structure of dewatering well point and construction method

Abstract

The invention discloses a waterproof casing pipe structure of a dewatering well point and a construction method, and belongs to the field of dewatering well waterproof structures. The waterproof casing pipe structure comprises a casing pipe I and a casing pipe II. The construction method comprises the following steps that before a raft cushion layer is poured, the waterproof casing pipe structure is fixed to a dewatering wellhead; a dewatering pump penetrates through the waterproof casing pipe structure and is put into a dewatering well for dewatering; an upper water stop steel plate and a lower water stop steel plate are arranged between a raft bottom rib and a surface rib and are poured in a raft; a water pump is taken out after a main body stops dewatering; a reinforcement cage with a bent anchor at the bottom is put into the waterproof casing pipe structure, the bent anchor part is anchored into the casing pipe I and penetrates into the lower portion of the casing pipe II, and reinforcements at the upper end of a reinforcement cage are lower than the top face of the raft; and then micro-expansion anti-seepage concrete which is one grade higher than the raft is poured into the casing pipe I and the casing pipe II, the concrete is cured after being vibrated compactly, and the curing time is not shorter than 14 days. According to the waterproof casing pipe structure of the dewatering well point and the construction method, the sealing time of a dewatering pipe is effectively shortened, a good waterproof effect is achieved, a basement is effectively prevented from moving upwards to the raft, and the cost of manpower, materials and the like for secondary treatment is reduced.

Description

technical field [0001] The invention relates to the technical field of the waterproof structure of a dewatering well, in particular to a waterproof casing structure and a construction method of a dewatering well point. Background technique [0002] The excavation depth of the foundation of newly built high-rise residential buildings is relatively deep, and basically all have civil air defense works. The groundwater level needs to be lowered during the construction phase, while civil air defense projects generally use piled raft foundations, and dewatering wells are generally set around the structure or at the pit for dewatering. In order to ensure that the structure construction is not disturbed by groundwater, the precipitation must also be carried out at the same time as the structure construction. [0003] In the actual construction, it was found that the sealing construction of the dewatering well has always been a relatively weak point. Some of them stopped lowering th...

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Problems solved by technology

[0003] In the actual construction, it was found that the sealing construction of the dewatering well has always been a relatively weak point. Some of them stopped lowering the operating water when the structure was constructed to the cushion, and the cushion concrete was directly poured into the dewatering well pipe, and the sealing effect was very good. Unsatisfactory, resulting in a large amount of groundwater seeping out of the surface of the cushion from the surroundings, making the waterproof construction unable to proceed normally and affecting the progress of the project

[0004] In specific construction, in some areas with rich groundwater, if the precipitation operation cannot continue after the main construction of the basement is completed, the building will not meet the requirements of the anti-floating design, which will cause great quality and safety hazards in the building. Without effective plugging measures, a large amount of groundwater seeps in, making the next process impossible

Moreover, the time difference between the stop of the dewatering operation and the closure of the downcomer and the time between the closure of the structural floor should be as short as possible, otherwise the groundwater will return to the foundation pit along the downcomer well, resulting in an increase in manpower and material costs for secondary waterproofing. And leave a quality hidden danger to the overall waterproofing of the foundation floor

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