Based on field loading test pile data in three engineering sites,it had a fitting analysis on the pile top load versus settlement curves(Q-S curves) and had a bearing capacity calculation of thin-wall cast-in-situ tubular piles.

Field tests and numerical simulation of working load influences on negative skin friction behaviors of piles;

The differences of negative skin friction(NSF) character between pile with working load and without working load are compared.

Settlement calculation of pile groups considering the pile compression;

The view of the telltale readings is useful for the analysis of pile compression and toe resistance was presented.

This paper presents the calculation method of pile body compression deformation with respect to BOTDR based on the load transfer analysis,and analyzes the law of pile body compression and deformation of over-length bored pile under pile top load in the static load test in combination with an engineering case.