桩土变形和承台变形对单桩竖向力的影响研究  

Research on the Effects of Pile-soil Deformation and Cap Deformation on Vertical Force of Single Pile

作　　者：王麒 郭东升 于建立 Wang Qi;Guo Dongsheng;Yu Jianli(China Construction Seventh Engineering Division Co.,Ltd.,Zhengzhou 450000,China)

机构地区：[1]中国建筑第七工程局有限公司,河南郑州450000

出　　处：《市政技术》2022年第2期150-153,200,共5页Journal of Municipal Technology

基　　金：弯梁外倾式异形拱桥关键技术研究及应用(ZJZYJZSJY-2021-1)。

摘　　要：为了研究桩土变形和承台变形对群桩基础中单桩竖向力的影响,分别采用规范简化公式和考虑桩土变形、承台变形的有限元方法对群桩基础中单桩竖向力进行计算,分析了产生误差的原因、规律和范围,并结合实际工程计算分析了复杂情况下单桩竖向力的分布情况。结果表明:规范简化公式把承台看作多点铰支、刚度无穷大的梁,计算误差一般在7%以内,满足工程要求;考虑桩土变形时,桩和承台可视为刚接的刚架,桩会根据其转动刚度的大小分担一部分弯矩,从而使承台弯矩变小、单桩竖向力变小;同时考虑桩土变形和承台变形时,刚架模型依然适用,不过空间效应会使单桩竖向力的确定变得复杂。In order to study the influence of pile-soil deformation and cap deformation on the vertical force of single pile among piles, the normal simplified formula and the finite element method considering pile-soil deformation and cap deformation are adopted to calculate the vertical force of single pile among piles. The causes, rules and scope of errors are analyzed. Combined with the actual engineering case, the vertical force distribution of single pile under complex conditions are calculated and analyzed. The results show that the normal simplified formula regards the cap as a beam with multipoint hinged support and infinite stiffness, and the calculation error is generally less than 7%,which meets the engineering requirements. Considering pile-soil deformation, the pile and cap can be regarded as rigid frame, which is rigidly connected, and the pile will share part of the bending moment according to its rotational stiffness so that the bending moment of cap and the vertical force of single pile can become smaller. Both pile-soil deformation and cap deformation being considered, the rigid frame model is still suitable. But the spatial effect will make the determination of vertical force of single pile complicate.

关 键 词：桩土变形 承台变形 单桩竖向力 规范简化公式 刚架模型 

分 类 号：TU473.11[建筑科学—结构工程] U443.15[建筑科学—土工工程]