Foundation pit confined water early warning equipment system and monitoring method

Abstract

The invention discloses a foundation pit confined water early warning equipment system and a monitoring method. The system is characterized by comprising a hydraulic communication structure, a temporary blockage tool and a water pressure monitoring system. The hydraulic communication structure comprises a hollow rectangular body, a permeable round hole matrix and a sliding groove, the hollow rectangular body is mounted in an underground diaphragm wall, the side of a soil facing face of the hollow rectangular body is flush with one side of a soil facing face of the underground diaphragm wall, the permeable round hole matrix is mounted on the soil facing face of the hollow rectangular body, within the range from the position, above the top face of a confined water layer, of the permeable round hole matrix by 0.5 to 1.5 m to the position, below the bottom face of the confined water layer, of the permeable round hole matrix by 0.5 to 1.5 m, a sliding groove is longitudinally formed in theside, close to the soil facing face of the hollow rectangular body, in the hollow rectangular body, the temporary blockage tool is inserted into the sliding groove and blocks the permeable round holematrix, the water pressure monitoring system is mounted in the hollow rectangular body and collects pore water pressure in the hollow rectangular body, and the system has the advantages that the confined water state in soil below an excavating layer in a pit can be provided in real time, and meanwhile the foundation pit excavating efficiency can be improved.

Description

technical field [0001] The invention relates to the field of foundation pit construction, in particular to a foundation pit pressurized water early warning equipment system and monitoring method. Background technique [0002] There are a large number of deep foundation pit projects in the construction of urban rail transit, and a large number of confined water formations will be encountered during construction. With the continuous excavation of foundation pits, the thickness of the water-resistant layer between the pit bottom and the pressure-bearing layer will become more and more thick. Small, when it is less than the critical thickness of the anti-surge, a surge accident may occur. In order to avoid the occurrence of the accident, the method of pumping and reducing the pressure is generally used, but the pumping of pressurized water will cause a great impact on the environment. The engineering control methods of confined water in foundation pits are mainly precipitation a...

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Problems solved by technology

[0002] There are a large number of deep foundation pit projects in the construction of urban rail transit, and a large number of confined water formations will be encountered during construction. With the continuous excavation of foundation pits, the thickness of the water-resistant layer between the pit bottom and the pressure-bearing layer will become more and more thick. Small, when it is less than the critical thickness of the anti-surge, a surge accident may occur. In order to avoid the occurrence of the accident, the way of pumping and reducing the pressure is generally adopted, but the pumping of pressurized water will cause a great impact on the environment

The engineering control methods of confined water in foundation pits are mainly precipitation and complete isolation. The effect of complete isolation is remarkable, but the construction is difficult and the project cost is high; the impact of precipitation on the surrounding environment is relatively large and there is a lack of accurate prediction. method, has certain safety hazards, and is currently mainly based on empirical judgments. Under this background, in order to ensure the safety of foundation pits, most projects have the problem of excessive extraction of pressurized water, which in turn has caused excessive harm to the environment.

In order to observe the state of confined water in real time, some experts and scholars have carried out research, such as the invention patent "A Confined Water Level Observation Well Structure and Multi-layer Water Level Observation Method". Although this method can observe the state of confined water, it requires In addition, setting up observation wells in the excavated strata will cost a lot, and will become an obstacle that needs to be protected during foundation pit excavation, reducing the efficiency of foundation pit excavation

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