桩承载力时效对桩土相互作用及沉降的影响分析

Effects of time-effect of pile's bearing capacity on pile-soil interaction and on settlement of pile-raft foundation

对软土中两根47 m长灌注桩分别在成桩28 d和1 750 d后进行了承载力试验,其极限承载力提高幅度达到30%左右。分析了单桩承载力随时间提高(称为时效)的机理,提出了单桩承载力时效对桩筏基础桩土相互作用影响的分析方法,并结合工程实例进行了分析。

Pile loading tests of two bored piles of length 47m in soft soil are carried out for 28 days and 1 750 days after they are constructed. In-situ test shows that the ultimate bearing capacity of these two single piles increased about 30 %. The mechanism of time-effect of bearing capacity of pile is analyzed; and method of analyzing the effects of the time-effect of a pile抯 bearing capacity on pile-soil interaction of pile-raft foundation is discussed with an engineering example.