层状地基中基于虚土桩模型的单桩沉降计算方法  

A NEW CALCULATION METHOD FOR THE SETTLEMENT OF SINGLE PILE BASED ON VIRTUAL SOIL-PILE MODEL IN LAYERED SOILS

作　　者：王奎华[1] 吕述晖[1] 吴文兵[1,2] 罗永健[1] 

机构地区：[1]浙江大学软弱土与环境土工教育部重点实验室,杭州310027 [2]中国地质大学(武汉)工程学院,武汉430074

出　　处：《工程力学》2013年第7期75-83,99,共10页Engineering Mechanics

基　　金：国家自然科学基金项目(50879077);中国博士后科学基金项目(2012M521495);中央高校新青年教师科研启动基金项目(CUG120821)

摘　　要：基于虚土桩模型及荷载传递法,针对理想弹塑性荷载传递函数,推导了均质地基中以桩侧土塑性发展深度为变量的桩顶荷载-沉降曲线计算方法,且进一步利用递推方法将其推广到层状地基中并给出了桩身轴力及桩侧摩阻力的计算方法。在此基础上,给出了荷载传递模型参数的选取方法并分析了虚土桩计算长度的影响因素及取值方法。然后,利用该算法分析了桩及虚土桩压缩模量对荷载-沉降曲线的影响。最后,结合工程实测数据,对比了计算荷载-沉降曲线、实测曲线和由规范方法得到的荷载-沉降曲线,结果表明:在一定的荷载范围内,采用基于虚土桩模型的单桩沉降计算方法计算得到的桩顶沉降值与实测值较为吻合,实际工程应用优于规范法。Based on a virtual soil-pile model and by virtue of an elastic-perfectly plastic model, the settlement analysis of a single pile embedded in layered soil is conducted by using a load transfer method. Firstly, the interaction between pile side soil and a pile is modeled as an ideal elastoplastic transfer model, and assuming the developmental plastic depth to be an independent variable, a new calculation method for the settlement of a single pile in homogeneous soil is derived and extended to the single pile settlement analysis in layered soil by a recursive method. On this basis, the analysis of the parameter selection of a load transfer model and the factors as well as the selection method of virtual soft-pile length are conducted. Then, by means of the presented method, the influence of pile-soil system parameters on load-displacement curves is studied. Finally, comparing the calculation results of this method with that of the measured and normative method, it is shown that： within a certain range of load, the pile top settlement calculated by this presented method is approximate to the measured value, and also superior to the normative method.

关 键 词：单桩沉降 层状地基 虚土桩模型 荷载-沉降曲线 荷载传递法 

分 类 号：TU473[建筑科学—结构工程]