Irrigation Method:

1. Large Bore Well Point Dewatering: Primarily involves drilling large bore wells within the dewatering area, installing filter pipes and deep well pumps to pump groundwater to the surface. Large bore well point dewatering covers a wider area due to the larger diameter of the well pipes and the presence of a deep well pump in each well.

2. Open Channel Dewatering Method; Open channel dewatering is a simple, relatively economical and quick method of dewatering. It involves excavating an open channel on both sides of the pipe trench, with the bottom elevation of the open channel being lower than that of the pipe trench, and a sedimentation well is set up.

Application Scope:

1. Sand and gravel or silt layers with high groundwater levels. For weakly permeable clay layers, measures such as electrical well points, deep well points, or combined dewatering can be taken to lower the groundwater level.

2. Measures are in place to ensure that ground subsidence near the site is kept within allowable limits.

3. The surrounding environment allows for some ground settlement.

4. Proven regional experience demonstrates minimal impact of precipitation on the surrounding environment.

5. Waterstop curtain is sealed, and the water level outside the pit does not drop significantly when precipitation occurs inside the pit.