Construction Surveying and Boring Arrangement

1. Based on the horizontal shape and size of the excavation pit, soil type, and groundwater flow, line marking is conducted to lower the water level depth and determine the drilling method.

The distance from the well center to the edge of the excavation pit depends on the drilling method of the drilling rig used.

When using jet grouting machines, the mud casing is set at 0.5 to 1.5 meters.

When using the casing method, it must be no less than 3 meters.

The spacing between pipe wells ranges from 10 to 50 meters, with a water table depth of up to 3 to 5 meters.

Burying the casing of the well casing

1. Boring: It is recommended to use the mud-boring wall method, where mud is injected into the hole as the drilling machine operates to protect the well wall and prevent collapse in case of groundwater leakage.

2. The borehole diameter is 150 to 250mm larger than the outer diameter of the well.

3. Prior to the well casing being lowered, the borehole should be cleaned and the filter screen kept clear.

4. A filtering layer composed of 3 to 15mm gravel is used between the well casing and the soil wall. Below ground level, up to 0.5 meters, the area is filled and compacted with clay.

Water Absorption System Installation

1. The suction pipe should be made of rubber or steel pipe with a diameter of 50-100mm, its lower end should be submerged below the low water level line during pipe well suction, and an anti-reverse valve should be installed.

A section of short steel pipe with a flange is installed at the top of the suction pipe.

The top outlet of the suction pipe is connected to a centrifugal pump with a diameter of 50 to 100 mm.

4. Typically, each well is equipped with a separate pump, with the elevation set as low as possible at the low suction point. If the height is insufficient, the pump can be placed inside the excavation pit.

When the water discharge of the pump exceeds several times the inflow rate of a single well, an additional main drainage pipe can be installed. Connect the corresponding number of suction pipes together, sharing a single pump.

Jingding Operations

After being energized, the mechanical parts, electric motor, drive shaft, current, and voltage should be checked regularly, and the water level drop and flow rate in the well should be observed and recorded.