The application of the clamp pressure sonic tube is as follows:
1) the method of connecting the pipe well (300) to the light well point precipitation is used in the foundation pit, and the precipitation on both sides of the subway shield tunnel is symmetrical, and the groundwater level is reduced to the elevation of 3.0m. 3 weeks before excavation, two dewatering wells in each section are used as well as well as recharge well to control groundwater level.
2) the dewatering begins at 3 weeks before the excavation of the foundation pit.
3) The project department assigns special personnel to take charge of precipitation and water level observation, at least daily average distance measurement to do a good job of water level records, to ensure that water level control in the elevation of 3M status.
4) after the concrete pouring in the floor of the subway, the water level in the pit and the dewatering well on the north side of the foundation pit are blocked, and the remaining three dewatering wells are blocked after the earth is filled.