PRE-DRILLING AND PROOF-DRILLING
Brief Introduction
Prior to the installation works of piles founded on rock or piles driven into bedrock, pre-drilling is carried out to identify the quality of the founding rock or rock socket and to determine the appropriate founding levels.
Proof-drilling is carried out at concrete/rock interface for piles founded on rock to check the quality of concrete contact with rock at the interface and the required grade of rock beneath the pile base. For piles driven into bedrock, proof-drilling is carried out to verify the rock head profile and hence assess the adequacy of the socketed length of the piles.