The Study on Distribution Characteristic of Positive Friction Resistance in Thick Loess Area

Abstract

The bearing capacity of pile foundation engineering in large thickness loess area is mainly provided by the positive frictional resistance of pile side during normal operation and load test. Compared with the coupling effect of side resistance and end resistance of short piles, the side resistance of long piles is clearer in the mechanical mechanism, especially the side resistance of long piles in the large thickness loess area with uniform soil quality is of more significance for analysis and research. Based on the statistical analysis of load test data of empty bottom pile, the formula of lateral resistance and displacement is fitted for three stages of pile-soil interaction. Based on the numerical simulation, the load test of empty bottom pile is inverted, and then the results are obtained: (1) The distribution curve of lateral friction within the pile range is inverted “S” type, and the distribution curve of pile-soil relative displacement within the pile range is “Z” type. There are three areas in the pile body for the distribution of lateral friction, namely the pile top area, the pile in the area and the pile bottom area. The distribution of pile-soil displacement can also be compared with the above three areas; (2) By comparing the lateral friction distribution with the pile-soil displacement distribution, it is found that the derivative relationship between lateral friction and pile-soil displacement is present in the range of pile body.