Layered water-stop device and method for preventing surge of pressurized water side wall of foundation pit depressurization well

Abstract

The invention relates to a layered water-stopping device and method for preventing and controlling the side wall surge of pressurized water in a step-down well of a foundation pit. A clay ball and a water-swellable ring arranged at intervals, the water-swellable ring is set outside the well pipe, has a water-swellable material and a waterproof membrane wrapped outside the water-swellable material, and the waterproof membrane is The water-swellable ring ruptures after being placed in place, exposing the water-swellable material; when pressurized water leaks, the water-swellable material in the water-swellable ring swells with water to form a vertical water-proof body. Compared with the prior art, the present invention can effectively make up for the further improvement of the anti-seepage performance of the decompression well under the condition of unknown clay ball sealing quality, especially when the sealing quality of the clay ball is not good and the plugging effect is not good, and the pressurized water In the case of seepage and upward movement along the bottom of the well, it can directly block the seepage path of the confined water and eliminate the safety hazard caused by the seepage of the step-down well.

Description

technical field [0001] The invention belongs to the technical fields of geological engineering, geotechnical engineering, and foundation pit engineering, and in particular relates to a layered water stop device and method for preventing and controlling surges of pressurized water side walls of foundation pit depressurization wells. Background technique [0002] The foundation pit dewatering is when the foundation pit is excavated, the groundwater level is higher than the excavation bottom surface, and the groundwater will continue to seep into the pit. Precipitation work due to the bottom piping and the decline of the bearing capacity of the foundation. In modern geotechnical engineering and foundation pit engineering dewatering construction operations, well point dewatering is a common and important treatment method. Well point dewatering is to arrange a certain number of depressurization wells around the foundation pit before excavation of the foundation pit. During the e...

AI Technical Summary

Problems solved by technology

Clay balls are commonly used for sealing holes and preventing seepage in depressurization wells. However, since clay balls are located at the bottom of the well, between the well pipe and the well wall, its sealing quality is often difficult to control to achieve a complete plugging effect. Sometimes it will cause the pressurized water to seep upwards along the side wall, which will seriously cause sudden surge, so that the depressurization well cannot play the role of depressurization

The applicant of the present invention found that the treatment measures for the side wall leakage problem have not been taken into account in the construction process of the decompression well at present, and it is urgent to conduct research on how to overcome the poor quality of clay balls and the side wall leakage of the decompression well

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