摘要
Abstract
The bearing capacity of jacked pile varies with timeafter the end of pile jacking,and the study on the time effect of bearing capacity of jacked pile has some implications for the design and construction of jacked pile.This paper,by taking the project Binhuyuan Community,Binhai economic development zone,Weifang City,Shandong Province as the test site,compares the measured data of two piles,studies the relationship between the general ultimate bearing capacity and ultimate compressive strength,and the growth law of tip resistance and shaft resistance,and also proposes the bearing capacity of jacked pile increase model in three stages.The results show that,the general ultimate bearing capacity is different from the ultimate pile load,which increases mainly in the 9 days after the end of pile jacking,and grows faster in the initial stage than the later stage.At 20 hours after the end of pile jacking,the contribution of tip resistance and shaft resistance to bearing capacity of pile is the same,50 percent respectively,called “contribution balance point ”.The increase of ultimate bearing capacity of the jacked pile is mainly determined by shaft resistance on 13 days after the end of pile jacking,“absolute hardening of shaft resistance” and “relative softening of tip resistance” occurred.Different soil layers provide different shaft resistance,the silty clay is the largest,sandy silt and silty soil are the second,and the silt soil is the smallest.The static pressure pile bearing capacity growth model is composed of three stages,the increase of the pile end resistance is only in the first stage,the large increase of the pile side friction resistance is concentrated in the first and the two stage,and slightly increases in the third stage.关键词
静压桩/隔时复压试验/侧摩阻力/端阻力/时效性Key words
jacked pile/interval re-pressed test/shaft resistance/tip resistance/time effect分类
建筑与水利
