Wuxi, Jiangsu – SJL-120 Rotary Jet Grouting Cut-off Wall – MJS Method – Subway Project

Location (Province): Jiangsu  

Location (City): Wuxi  

Drill Model: SJL-120 Rotary Jet Drill Rig  

Drill Tooling: Ammann 142 series multi-hole drill bit, drill pipe, swivel  

Process Type: Rotary jet grouting cut-off (water stop)  

Construction Method: MJS Method  

Stratum Conditions: 1-4m backfill layer, 4-20m clay layer  

Construction Angle (°): 90  

Pile Diameter (mm): 2000  

Hole Depth (m): 20  

Construction Method  

Equipment Configuration:  

One Ammann SJL-120 drill rig  

Backup Configuration:  

One 230 high-pressure pump  

One 165 high-pressure pump  

One 90E high-pressure pump  

One 9m³ air compressor  

Nozzle Size: 2.8

1. Mark the position of each pile according to requirements.  

2. Use a pilot drill rig with a 280mm bit. Control the penetration rate to prevent deviation. After reaching the 

required depth, disassemble the drill pipe.  

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, mixing plant, 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 grouting nozzle and cutting water nozzle with transparent tape. Assemble the drill pipe sections (check

 the sealing rings when connecting). Finally, install the swivel.  

Ammann engineer on-site guidance.  

6. Start the air compressor, high-pressure pumps, and mixing plant. Set the 230 high-pressure pump pressure to

 40MPa, the 90E pump suction pressure to 15MPa, and air pressure to 1.0MPa. Use 360° swing grouting with a

rotation speed of 6r/min and a step feed rate of 30mm/min. Monitor rotation pressure changes and slurry return 

during construction. After disassembling the drill pipe, clean it promptly to prevent nozzle blockage.