Max dia – Unlimited [ (IS 2911 PART (1) SEC (2) ]
The system is very useful in congested areas where noise is prohibited. Here the bore is made by drilling the ground using a mechanically operated auger,chisel or by a bailer. The boring is done with the bailer which has provision for sending bentonite solution under pressure.
The bored muck is carried to the surface by the circulating bentonite (So it is called direct mud circulation system) Once the hard strata is reached an appropriate chisel is used to drill through the hard strata for socketing requirements. The weight of the chisel depends on the pile diameter and the capacity to be mobilised The stratum for termination is identified by observing the penetration achieved for the given chisel energy. Once the boring is complete the borehole is washed by circulating bentonite continuously. The specific gravity of the out flow solution is measured to ensure that the bore is properly cleaned. Then the reinforcement is lowered followed by tremmie and the concreting is done
MECHANICALLY OPERATED DMC RIG FOR BORED PILE
The mechanically operated auger equipment has certain distinct advantages over the rotary rig which are hydraulically operated. In the case of hydraulic rigs, when the auger drills the bore and later when it is being withdrawn it generates large suction force which leads to collapse of the bore. Further it does not have provisions for DMC due to which cleaning of boreholes cannot be ensured. In the case of mechanically operated rig there is provision for DMC which ensures effective clening of the bore hole as in this case bentonite is circulated under pressure Moreover pulling out of auger is so gradual that the auger comes out with least suction effect.
- Construction Oversight
- Safety and Health Inspection
- Environmental Engineering
- Environmental Consulting
- Reliability and Safety Assessment