【Construction case】SJL-120 rotary jet drill in large diameter disturbance

Stratum situation

Location (province): Jiangsu Province

Location (city): Wuxi

Drill model: SJL-120 rotary jet drill

Drill tool configuration: 142 porous drill bit, porous drill rod, water swivel

Process type: rotary spray and water stop

Construction technology: large diameter disturbance construction method, ± 90 pendulum spray

Stratigraphy: 1-37 m soil layer

Construction Angle (°): 90

Pile diameter (mm): 2,000

Pile depth (m): 20-37

Construction technology

Construction configuration

One SJL-120 rotary jet drill, hole drill, 230 high pressure pump, 165 high pressure pump, 90E high pressure pump, 12 cubic air compressor, nozzle 2.8

Work progress

1、Determine the position of each pile as required.

2、250mm drill hole.

* Pay attention to the footage speed to prevent deflection during the construction process, and remove the drill pipe after hitting the required depth

3、After installing the SJL-120 rotary spray drill with the 142 porous drill (inner clamp), align the hole position according to the requirements, adjust the verticality, and support the leg.

* Before formal construction, test and check whether the display and data recording of high-pressure pump, mixing station, air compressor, nozzle, flow meter, pressure sensor, background data transmitting terminal and drilling rig receiving module are normal.

4、Seal the main slurry nozzle and the cutting water nozzle with transparent tape, and connect the porous drill rod in turn.

* Check the sealing ring when connecting the drill pipe

5、Finally, install the shunt;

6、Open air compressor, high pressure pump and mixing station, set construction parameters according to the formation conditions: 230 high pressure pump slurry pressure 40 Mpa, 90E reverse suction 15 Mpa, pressure 1.0 Mpa, ± 90 swing swing speed 8 r/min, step stroke 25mm / min.

* Pay attention to the change of rotary pressure and slurry return during construction

* After removing the drill pipe, clean the drill pipe in time to prevent hole plugging