独立基础偏心荷载下地基冲切力的精确计算  

An Exact Formula for Calculating the Punching Force of Subsoil under Eccentric Loading of Single Foundation

作　　者：赵少飞[1] 齐宏伟[1] 王丽红 

机构地区：[1]华北科技学院土木工程系,北京101601 [2]河北省燕郊经济技术开发区住房和规划建设局,河北三河065201

出　　处：《地下空间与工程学报》2011年第2期296-299,共4页Chinese Journal of Underground Space and Engineering

基　　金：河北省科技攻关项目(07215676)

摘　　要：柱下独立基础偏心荷载作用下,《建筑地基基础设计规范》(GB 50007—2002)采用简化公式计算地基冲切力,即忽略地基净反力的实际分布,而简单地采用基础边缘的最大净反力进行计算。考虑偏心荷载作用下地基净反力分布变化,假设地基净反力为线性变化,推导了地基冲切力的精确计算公式,并对目前《规范》简化计算公式进行了误差分析。算例结果表明,冲切力简化公式虽然偏于安全,但其计算误差主要随着基础有效高度、地基最大和最小净反力的差值而变化,最大误差可能达到15%以上。当独立基础有效高度较小、地基净反力变化较大时,需要根据地基冲切力的精确计算公式进行基础高度设计。In the Code for Design of Building Foundation（GB 50007—2002）,a simplified formula is suggested to calculate the punching force by subsoil applying to a single foundation under eccentric loading caused by a column,in which the maximum of the net foundation pressure is introduced for ignoring its actual distribution.In this paper,an exact formula is deduced for the punching force by subsoil,in which variety of the net foundation pressure is considered based on the hypothesis of its linear distribution.Errors of results are analyzed by the simplified formula in the Code.Results of examples show that the error varies with the effective height of foundation,and difference of the maximal and minimal values of the net foundation pressure.The punching forces might be overestimated by 15% for several cases though the results are safe.The punching force is calculated necessarily by the exact formula in a design of height of a single foundation if its effective height is smaller and difference is larger between the maximal and minimal values of the net foundation pressure.

关 键 词：独立基础 偏心荷载 冲切力 精确计算 

分 类 号：TU470.3[建筑科学—结构工程]