Diamond Drilling / Concrete Coring
Diamond coring is carried out for one of the following reasons:-
- To form a hole through an area of hard standing, to allow the drilling of a borehole.
- To recover a sample of concrete, masonry or Tarmacadam for inspection and testing.
All works are undertaken in accordance with BS 5930 (1990), BS 1377 (1990) and the BDA 'Code of Safe Drilling Practice' and 'Guidance Notes for the Safe drilling of Landfills and Contaminated Land, and are supervised by an suitably qualified engineer.
Prior to drilling, the area is checked for the presence of buried services by examination of the service drawings. All locations are scanned utilising a Cable Avoidance Tool (CAT) in conjunction with a Genny prior to the intrusive works.
The coring rig is generally secured to the surface to be drilled (floor, wall etc) using an anchor bolt or vacuum system. The drill motor is generally powered by 110v a electric power supply from either a generator or the mains via a transformer.
The drill bit is cooled and kept clear of cuttings by use of a flushing medium, usually water, which is pumped down the centre of the drill string and returns, with any debris, through the annulus. The water is usually contained within 25l containers and pumped to the cutting face using either an electric pump or a pressurised container.
The core produced is circular in cross section of the nominal specified diameter throughout the core length. Drill runs will not generally exceed 0.5m in length, and the core barrel will be removed from the drill hole as often as is required to obtain the best possible core recovery.
The resultant core is logged and if necessary subsampled by an engineer or geologist in general accordance with BritishStandard BS 5930:1999.
The resultant core hole is generally backfilled with similar material to existing or as required by the contract.