Tianjin – SJL-120 Rotary Jet Grouting Reinforcement – RJP Method

Location (City): Tianjin  

Drill Model: SJL-120 Rotary Jet Drill Rig  

Drill Tooling: G4142 Multi-hole Pipe  

Process Type: Rotary Jet Grouting Reinforcement  

Construction Method: RJP Method  

Stratum Conditions: 1-3m backfill soil; 4-10m soil layer; 11-30m silty clay  

Construction Angle (°): 90  

Pile Diameter (mm): 2000  

Pile Depth (m): 30  

Construction Efficiency (min): 720

Construction Method

Equipment Configuration:  

One SJL-120 drill rig, one geological drill rig, one 230 high-pressure pump, one 90E high-pressure pump, one 13 m³

 air compressor, nozzle size 2.8

1. Mark the position of each pile as required.

2. Use a pilot drill rig with a 250 mm bit. Control the penetration rate to prevent deviation. After reaching the required

 depth, inject a certain amount of bentonite to prevent hole collapse.

3. Install the bit on the SJL-120 drill rig (clamp it tightly). Align with the hole position as required, adjust verticality, and

 extend the supports.

4. Check the high-pressure pumps, air compressor, nozzles, flowmeter, pressure sensors, data transmission terminal, 

receiver module on the rig, display, and data recording to ensure everything is functioning properly.

5. Seal the main grouting nozzle and cutting water nozzle with transparent tape. Assemble the drill pipe sections (pay

 special attention to checking the sealing rings when connecting). Finally, install the swivel.

6. Start the air compressor and high-pressure pumps. Cutting water pressure: 35 MPa, grouting pressure: 40 MPa, air

 pressure: 0.8 MPa, 90° swing grouting with a rotation speed of 3 r/min and a step feed rate of 25 mm/min. Monitor

 rotation pressure changes and slurry return during construction. After disassembling the drill pipe, clean it promptly 

to prevent nozzle blockage.