基于虚土桩模型的层状地基群桩沉降研究  

Settlement research of pile groups in layered soils based on virtual soil-pile model

作　　者：辛冬冬 张乐文[1] 宿传玺 XIN Dong-dong ZHANG Le-wen SU Chuan-xi(Geotechnical and Structural Engineering Research Center, Shandong University, Jinan, Shandong 250061, China)

机构地区：[1]山东大学岩土与结构工程研究中心,山东济南250061

出　　处：《岩土力学》2017年第8期2368-2376,2394,共10页Rock and Soil Mechanics

基　　金：国家自然科学基金项目(No.41572275)~~

摘　　要：群桩中各基桩之间的加筋与遮帘效应和桩端土体变形是群桩沉降计算中的关键部分,极大地影响计算结果的准确性,然而,目前相关的研究仍显不足。采用剪切位移法原理分析了各基桩之间的加筋与遮帘效应,通过荷载传递法原理推导出层状地基土中各基桩桩底、顶之间的沉降与轴力关系式;基于虚土桩模型,探讨了虚土桩长度的影响因素并给出了定量计算公式,得到了层状地基土中各虚土桩顶、底之间的沉降与轴力关系式;利用基桩与虚土桩的边界条件和平衡关系确定柔度系数矩阵,进而根据不同的承台形式求得群桩沉降。工程案例计算表明,理论计算与实测值吻合较好,该方法具有较高的准确性。其研究结果对群桩沉降计算理论的发展具有一定的补充和推动作用。The reinforcing and restraining effect of pile groups and the soil deformation under the pile tips are the key problems in settlement calculation of pile groups. However, the research on pile groups settlement is insufficient and needs to be continued. The reinforcing and restraining effect of pile groups was analyzed using the shear displacement method. The relations of settlement and axial force between bottom and top of each pile in layered soils were deduced by the load transfer method, respectively. Based on virtual soil-pile model, the calculation formula of virtual soil-pile length was provided. The relations of settlement and axial force between top and bottom of each virtual soil-pile in layered soils were obtained. Flexibility coefficient matrix was ascertained by the boundary conditions and the balance equations of pile section and virtual soil-pile section. Pile groups settlement was obtained based on different pile cap types. Lastly, case study indicated that settlement predicted by the present method agrees well with those measured from real test of engineering cases. The proposed method has high accuracy. The research played a complementary and promoting role on the development of settlement theory of pile groups.

关 键 词：群桩沉降 虚土桩模型 加筋与遮帘效应 层状地基 柔度系数 

分 类 号：TU473[建筑科学—结构工程]