PCC桩复合地基桩土应力比的计算及影响因素分析  

Calculation and Influencing Factors of Pile-Soil Stress Ratio of PCC Pile Composite Foundation

作　　者：卢长娜[1] 姜景山[2,3] 

机构地区：[1]南京信息工程大学数理学院,南京210044 [2]江苏省交通科学研究院股份有限公司岩土工程设计研究所,南京211112 [3]河海大学岩土力学与堤坝工程教育部重点实验室,南京210098

出　　处：《长江科学院院报》2011年第11期77-82,共6页Journal of Changjiang River Scientific Research Institute

基　　金：国家自然科学基金项目(40906048)

摘　　要：PCC桩是一种适合软土地区加固的刚性桩,以大面积PCC桩复合地基中的一个桩-土-垫层单元为研究对象,考虑桩-土-垫层的共同作用,提出了PCC桩复合地基桩土应力比的一种计算方法。该方法假定桩土界面的摩阻力与桩土相对位移为理想弹塑性关系、同一水平面上桩间土与桩芯土沉降相同、桩端土符合Winkler地基模型,考虑桩-土-垫层的协同作用机理,推导出了PCC桩复合地基桩土应力比和沉降的计算公式,并根据推导出的公式对桩土应力比的影响因素进行了分析,为PCC桩复合地基优化设计提供参考和依据。The cast-in-situ concrete thin-wall pipe pile（PCC pile） is a kind of rigid pile suitable for reinforcing soft foundation.A new method of calculating the pile-soil stress ratio of PCC pile composite foundation is presented taking the combined action of pile-soil-cushion into account.The relationship of frictional resistance and relative displacement between the pile shaft and the surrounding soil is idealized as perfectly elastoplasticity;meanwhile,settlement of soil between the piles and inside the piles at the same depth is assumed to be equal,and the soil at the pile tip is considered to be in conformity with Winkler ground model.Based on these assumptions,the calculation formulas for pile-soil stress ratio and settlement are derived through analyzing the pile-soil-cushion interaction.The influencing factors of pile-soil stress ratio are discussed according to the obtained formulas,which are beneficial to the optimal design for PCC pile composite foundation.

关 键 词：PCC桩复合地基 刚性桩 桩土应力比 沉降 优化设计 软土地基处理 

分 类 号：TU473.1[建筑科学—结构工程]