软土地区复合桩基础适用条件的探讨  

Discussion on applicable conditions of composite pile foundation in soft clay

作　　者：周峰[1,2] 刘壮志[2] 赵敏艳[2] 

机构地区：[1]东南大学交通学院,南京210096 [2]南京工业大学土木工程学院,南京210009

出　　处：《水文地质工程地质》2010年第2期87-90,共4页Hydrogeology & Engineering Geology

基　　金：国家自然科学基金(50678083);江苏省高校自然科学基础研究项目(08KJB560002);江苏省博士后科研资助计划(0802011B)

摘　　要：复合桩基的根本是桩土共同作用,而桩土共同作用的前提则是桩土变形协调,基桩与地基土的支承刚度通常存在数量级上的差异,因此要使桩土的变形协调,必须要采取一定的措施。以桩土共同作用机理为根本对复合桩基的使用条件进行了探讨,指出天然地基承载力满足率小于0.5而采用复合桩基时,桩土共同作用无法形成,最终使整个建筑物的安全度降低;天然地基承载力满足率大于0.6甚至0.7时,复合桩基整体安全度虽容易满足,但整体偏于保守,另外还容易缩小复合桩基适用范围。建议复合桩基使用条件中天然地基承载力满足率大于等于0.5即可。The root of composite pile foundation is pile - soil interaction, while deformation coordination between piles and soil is the precondition of the pile - soil interaction. Larger difference of bearing stiffness of piles and soil is existent usually, so certain measures must be taken to ensure deformation coordination. This paper discussed on the application condition of composite pile foundation based on mechanism of pile - soil interaction, and concluded that when the rate of bearing capacity of natural subgrade was less than 0.5, the composite pile foundation could not realize interaction and made the safety degree of the whole building decreased ; when the rate of bearing capacity of natural subgrade was more than 0.6 and even 0.7, although the safety degree of composite pile foundation should be satisfied easily yet the integral safety degree was conservative, besides, it was easy to reduce the application scope of the composite pile foundation. This paper suggested that the reasonable rate of bearing capacity of natural subgrade was equal or greater than 0. 5 in application range of composite pile foundation.

关 键 词：差异沉降 复合桩基 支承刚度 安全度 

分 类 号：TU447[建筑科学—岩土工程] TU473.11[建筑科学—土工工程]