Working Principle of Hydraulic Diaphragm Wall Grab:
1. Making guide wall;
2. The machine digs along the guide wall; and at the same time, using inclinator to measure the verticality;
3. Adjust the grab verticality to keep the wall precision;
4. Slurry should be used to prevent wall collapse;
5. And finally clean the wall bottom, place the cage and then concrete the cement.
Features of Hydraulic Diaphragm Wall Grab:
1. Low vibration and noise, so it can also work during night;
2. Electron detector, inclinometer and hydraulic push-plate are equipped to control the depth and verticality;
3. High wall strength: thus the walls can bear huge side pressure and avoid groundsill sinking and landslip;
4. Good penetration resistance;
5. Cost Saving: functions like soil retaining, water stealing and weight bearing, etc are all integrated;
6. Can be used as the rigid foundation to replace shafts, and other foundation.
Applications of Hydraulic Diaphragm Wall Grab:
The Hydraulic Diaphragm Wall Grab can be used in the deep pit wall of subway, underground works, garage and street, as well as in underground transformer substation and high building’s basement.
It especially can be used in deep pit wall in dense buildings of cities.
Construction Procedure:

Guide Wall:
Parameters of Hydraulic Diaphragm Wall Grab:
| Model | SG22 | SG30 | SG35 | SG35A | SG40 | SG40A |
| Wall width (m) | 0.22-0.6 | 0.35-1.0 | 0.3-1.2 | 0.3-1.2 | 0.35-1.2 | 0.35-1.5 |
| Wall depth (m) | 45 | 50 | 60 | 60 | 70 | 70 |
| Max traction force(kn) | 280 | 300 | 350 | 350 | 400 | 400 |
| Main winch pulling force | 140 | 160 | 200 | 200 | 220 | 2*200 |
| Engine output (kw) | 194 | 194 | 194 | 194 | 261 | 263 |
| System pressure (Mpa) | 30 | 30 | 30 | 30 | 30 | 30 |
| Pump flow(L/min) | 2×230 | 2×260 | 2×260 | 2×260 | 2×280 | 2×380 |
| Diesel motor | Cummins 6CAT5.9-C |
Cummins C8.3-C(6CTA) |
Cummins C8.3-C(6CTA) |
Cummins C8.3-C(6CTA) |
Caterpilla r C-9 |
QSM11-C |
| Max rotating speed of motor (rpm) | 2100 | 2200 | 2200 | 2200 | 1900 | 1900 |
| Chassis type | R455LC-7 JT45 | R305LC-7JT70 | R455LC-7JT70 | R455LC-7JT70 | CAT330 DTC325VH |
R455LC-7JT70 |
| Distance of outside track (mm) | 3200-4300 | 3200-4300 | 3200-4300 | 3200-4300 | 3000-4300 | 3200-4300 |
| Track board width (mm) | 800 | 800 | 800 | 800 | 800 | 800 |
| Traction force (kn) | 250 | 500 | 500 | 500 | 500 | 500 |
| Moving speed (kn/h) | 1.5 | 1.5 | 1.5 | 1.5 | 1.5 | 1.5 |
| Weight (except for grab )(t) | 42 | 49.5 | 53 | 60 | 57 | 63 |
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