A simplified calculation for the pile top settlement of bored piles rested on the middle-weathered bedrock

Based on the statistical analysis of results from the static load tests of about 200 bored piles rested on the middle-weathered bedrock in Zhejiang province, the measured compression of pile shaft was analyzed using the elastic theory, and then a simplified method for calculating the pile shaft compression was presented including a pile shaft compression factor, ξ. Moreover, statistical results show that, for the pile embedded into a middle-weathered bedrock, the percentage of the settlement at pile head caused by the pile shaft compression is about 80~95%. In addition, a simplified method for calculating the pile top settlement was given, taking advantage of the pile shaft compression factor and the ratio of the pile shaft compression to the pile top settlement. It can be concluded that, the present calculating method can consider the influence of the plastic pile shaft compression on the settlement at pile top, due to that all the parameters of the present method are derived from the statistical results of the static load tests.