饱和软土地基中PHC群桩贯入过程的能量耗散模型  

The Energy Dissipation Model of PHC Pile Group for Penetration Process in Saturated Soft Soil Foundation

作　　者：刘镇[1,2] 周翠英[3,2] 

机构地区：[1]中山大学海洋学院,广州510275 [2]中山大学岩土工程与信息技术研究中心,广州510275 [3]中山大学工学院,广州510275

出　　处：《地球科学（中国地质大学学报）》2011年第3期587-593,共7页Earth Science-Journal of China University of Geosciences

基　　金：国家自然科学基金重点项目(No.41030747);国家自然科学基金面上项目(No.40672194);国家"863"高技术计划项目(No.2007AA11Z112);教育部博士学科点基金项目(Nos.2006055806;20090171110044);广东省自然科学基金重点项目(Nos.06104932;013188);广东省科技计划项目(No.2010A030200007);广东省高层次人才计划项目(No.39000-5221001);广州市科技支撑计划项目(No.2010GN-D00011);中山大学后备重点课题(No.1132169)

摘　　要：软土地基中群桩稳定性分析是岩土工程的难点之一.通过对饱和软土地基中群桩贯入全过程的力学分析,结合群桩效应与工作性能,根据功能平衡原理,建立了贯入过程中附加应力(含超静孔隙水压力)引起的耗散能量与外力做功、弹性势能三者的平衡关系;同时,针对饱和软土地基中高预应力管桩(PHC)的排土特性,结合现行桩基规范,分别给出了超静孔隙水压力势能、挤土耗散能、重力做功、超静孔隙水压力做功、摩擦耗能、土体弹性势能等的定量表达,构建了PHC群桩贯入过程的能量耗散模型;在此基础上,导出了局部能量安全系数与整体能量安全系数.将上述模型应用于某工程PHC群桩基础的稳定性分析中,并与数值模拟结果对比,验证了该模型的合理可靠性,对饱和软基中PHC群桩稳定性状态的判别具有一定指导意义.Stability analysis of pile group in soft soil foundation is one of the difficult issues challenging geotechnical engineering.According to Energy Balance Principle,the equilibrium relationship among dissipation energy caused by additional stress（including excess pore water pressure） in penetration process,external work and Elastic Potential Energy is established,based on mechanical analysis of the whole process of pile group penetration test in soft soil foundation,combined with pile group effect and working performance of pile group.Meanwhile,quantitative expressions of potential energy of excess pore water pressure,soil-compacting dissipated energy,work of gravity,work of excess pore water pressure,friction energy dissipation and elastic potential energy of soil are given in accordance with the soil-compacting characteristic of pipe pile prestressed high strength and current code of pile foundation design,and energy dissipation model of PHC pile group in penetration process is constructed.Furthermore,the safety factor of local energy and total energy is derived on the basis of above-mentioned work.The reliability of the energy model is verified by its application to the stability analysis of PHC pile group foundation in a project and the comparison with the numerical simulation results,which is of significance for guiding discrimination of the stability of PHC pile group in soft soil foundation

关 键 词：饱和软土地基 PHC群桩 岩土工程 能量耗散模型 稳定性分析 

分 类 号：TU753.3[建筑科学—建筑技术科学]