碎石桩复合地基非线性固结解析解  

Analytical solution for nonlinear consolidation of stone column reinforced composite ground

作　　者：卢萌盟[1,2] 谢康和[2] 王玉林[2] 蔡新[2] 

机构地区：[1]中国矿业大学(徐州)深部岩土力学与地下工程国家重点实验室力学与建筑工程学院,江苏徐州221008 [2]浙江大学软弱土与环境土工教育部重点实验室,杭州310058

出　　处：《岩土力学》2010年第6期1833-1840,共8页Rock and Soil Mechanics

基　　金：中国矿业大学青年科研基金资助项目(No.2009A008);中国矿业大学人才引进资助项目;国家自然科学基金项目资助(No.50679074)

摘　　要：通过引入土体的e-lgσ和e-lgk对数模型,考虑了土体固结过程中压缩模量非线性增长和渗透系数非线性减小的特征,给出了一种碎石桩复合地基非线性固结解析解,并对复合地基的非线性固结性状进行了分析。结果表明,按应力和按变形定义的两种固结度不相等,按变形定义的固结度一般大于按应力定义的固结度;当压缩指数小于渗透指数时,不考虑土体的非线性特征会低估地基的固结度,而当压缩指数大于渗透指数时,不考虑土体的非线性则会高估地基的固结度;对于按应力定义的固结度来说,当压缩指数小于渗透指数时,随着附加应力的增大,地基固结速度加快,而当压缩指数大于渗透指数时,附加应力增大,地基固结减慢;对于按变形定义的固结度来说,不论压缩指数大于还是小于渗透指数,附加应力增大,地基固结速度总是加快。By incorporating the logarithm models of e-lgσ and e-lgk of soil,the characteristics of the nonlinear increase in the soil＇s compressive modulus and the nonlinear decrease in the soil＇s permeability during consolidation were considered. Based on the above characteristics,an analytical solution was developed for the consolidation of stone column reinforced composite ground. The nonlinear consolidation behavior of composite ground was analyzed and the results show：the average degree of consolidation （ADC） in terms of stress is not equal to that in terms of deformation; in addition,the ADC in terms of stress is greater than that in terms of deformation. When the soil＇s compressive indices are lower than the permeability indices,ignoring the soil＇s nonlinearity will under-estimate the consolidation rate of the composite ground; however,when the soil＇s compressive indices is greater than the permeability indices,the reverse is true,i.e. ignoring the nonlinearity will over-estimate the consolidation rate. For the ADC based on stress,when the soil＇s compressive indices are lower than the permeability indices,the increase in the stress increment within the ground due to the external loads leads to an acceleration of the consolidation rate; however,when the compressive indices is larger than the permeability indices,the increase in the stress increment causes a reduction in the consolidation rate. For the ADC in terms of deformation,whether the compressive indices are lower or larger than the permeability indices,an increase in the stress increment within the ground always accelerates the consolidation rate of the composite ground.

关 键 词：固结 复合地基 碎石桩 非线性 对数模型 压缩指数 渗透指数 

分 类 号：TU470[建筑科学—结构工程]