摘要：Pre-drilling is a widely used technique to get the detailed geological condition at the location of the bored pile foundation prior to its construction. It is often a necessary step for bored piles supported by strata, as its results are helpful for finalizing the pile length in design stage, which often requires the pile to be embedded into the rock strata at certain depth. The aim of the paper is to find the optimal (normally the lowest) point of rock strata at the purposed pile location, so that the optimal length required for the pile can be determined. To achieve this, geological prospecting data of the site needs to be analysed and the optimal pre-drilling point needs to be determined. The model developed by this study is based on the geological prospecting data and the pre-drilling results of a real project with a sharp slope of strata. It is found that by using the method introduced in this study, higher accuracy results could be obtained with less pre-drilling works required, hence the time and the cost of pre-drilling can be greatly reduced.
