桩基水平承载力群桩效应系数试验研究  

Experimental study on the effect coefficient of pile group horizontal bearing capacity

作　　者：任鑫健 高文生 Ren Xinjian;Gao Wensheng(China Academy of Building Research,Beijing 100013,China)

机构地区：[1]中国建筑科学研究院有限公司,北京100013

出　　处：《建筑科学》2020年第7期106-114,共9页Building Science

摘　　要：本文通过桩基水平静载模型试验,对水平荷载作用下桩基础的承载特性与群桩效应系数进行研究。研究表明:①灌注桩在水平荷载作用下,大致可分为三个工作阶段:直线变形阶段、弹塑性变形阶段和破坏阶段;②根据《建筑桩基技术规范》(JGJ 94—2008)计算所得的群桩效应系数较实测值偏小,规范偏安全;③在群桩效应的作用下,群桩中各基桩荷载分担不均匀,前排角桩分担荷载最大,但桩身(顶)弯矩最大值仅为同等位移条件下桩顶自由单桩桩身弯矩最大值的0.4倍左右;④桩间距一定时,桩数的增加对桩基水平承载力的提高程度较小,但可以使群桩中各桩的荷载分担更为均匀。文中的相关试验成果可为单、群桩基础水平承载机理的进一步研究提供依据。In this paper,the horizontal static load model test of the pile foundation is used to study the bearing characteristics of the pile foundation and the group pile effect coefficient under the horizontal load.The research shows that:①the cast-in-place pile can be roughly divided into three working phases under the horizontal load:Straight deformation stage,elastoplastic deformation stage and failure stage;②the group pile effect coefficient calculated according to the"Technical Specifications for Building Pile Foundations"JGJ 94—2008 is smaller than the actual measured value,and the standard is safer;③under the effect of the effect,the load sharing of each foundation pile in the group pile is uneven,and the front corner pile has the largest load sharing,but the maximum value of the bending moment of the pile body(top)is only the maximum under the same displacement,the value is about 0.4 times;④when the pile spacing is constant,the increase in the number of piles increases the horizontal bearing capacity of the pile foundation to a small extent,but it can make the load sharing of each pile in the group pile more uniform.The related experimental results in this paper can provide a basis for further research on the horizontal bearing mechanism of single and group pile foundations.

关 键 词：水平承载力 群桩效应系数 桩顶约束效应 桩的相互影响效应 基底摩阻效应 

分 类 号：TU473.1+1[建筑科学—结构工程]