粘性土中大直径钻孔灌注桩单桩沉降分析

根据大直径钻孔灌注桩在桥梁工程中应用研究,以及试桩静载荷试验和桩身应力测试结果,在单桩沉降分析计算理论系统分析的基础上,采用了杆系结构有限单元法与荷载传迭代法耦合的混合法.采用Fortran语言,编制了计算程序SPSA1.单桩沉降分析计算中,采用三直线模型考虑了桩身与桩周边界上的剪切滑移非线性;并改进了有限单元法中初应力迭代技术,以考虑荷载传递关系的软化特征.同时,就桩身材料非线性,对单桩沉降分析计算的影响进行了讨论.笔者的方法和成果,可以作为今后大直径钻孔灌注桩研究和相关规范修订时参考.

An Analysis of settlement of single piles in cohesive soils

Based on the application study of large diameter bored piles(LDBPs)used in bridge engineering and utilizing the data of static loaded tests and pile shaft testing,one hybrid method of finite element analysis of rod structure coupling with load transfer approach for single piles settlement was established in the result from the analysis of the methodology of predicting settlement of single piles in a systematic way. One program SPSA1 written in Fortran had been realized triumphantly. In the methodology of predicting settlement of single piles hereinbefore,the non-linear behavior of the relationship of stress and strain in the interface between pile shaft and media surrounding it was described by the Trilinear Model,and the softening characteristic of the relationship had be taken into account due to modification of initial stress technique in FEM. The non linear behavior of pile shaft material exerting influence on the single piles settlement was discussed. The documentation gives guidance for future research and development of the design criterion for LDBPs.