考虑坑壁位移和土压力方向的直撑力学特性  

Mechanical characteristics of straight brace considering displacement of foundation pit and direction of earth pressure

作　　者：宋明健[1,2] 汤连生[1] 胡辉[3] 王大志[4] 徐通[4] 

机构地区：[1]中山大学地球科学系,广州510275 [2]中山大学工学院,广州510275 [3]暨南大学土木工程学院,广州510632 [4]四川中成煤炭建设(集团)有限责任公司,成都610072

出　　处：《岩土力学》2009年第7期2031-2036,共6页Rock and Soil Mechanics

基　　金：国家自然科学基金资助项目(No40872205);全国高等学校博士学科专项科研基金资助项目(No20070558032);广东省自然科学基金资助项目(No07003738);广东省科技计划资助项目(No2008B030303009)

摘　　要：鉴于基坑支护中常见的直撑设计一般都没有考虑基坑位移和土压力的变化,总结了土压力和基坑位移之间非线性关系的研究现状,分析了随坑壁转动时土压力大小和方向的变化规律。在此基础上,推导了直撑轴力和坑壁位移之间、以及直撑纵向变形与坑壁位移之间的数学关系式。结合工程实例,进一步研究了直撑轴力和变形随基坑初始位移、支撑点、土压力作用点、土体与挡土结构间摩擦角等因素变化时的发展变化规律。研究表明,直撑轴力及其变形随基坑位移、支撑点高度、土体与挡土结构之间摩擦角的增加而减小,随土压力作用点高度的增加而增大,与基坑初始位移值基本无关。It is generally realized that earth pressure will change with the deformation and displacement of foundation pit. But at present the design of straight brace does not almost consider earth pressure changing with displacement of foundation pit. Firstly, the researches and achievements on the nonlinear relation of earth pressure and the displacement of foundation pit are summarized. Secondly, the rules on earth pressure changing with the displacement and movement of the side of foundation pit are discussed. On the basis of the present researches and the change rules on earth pressure changing with displacement of foundation pit, new formulas of axial force and deformation of straight brace considering the rotation or movement of the side of foundation pit are presented. At last, the curves of axial force and deformation of straight brace changing with some factors are obtained. Those factors include different initial displacement of foundation pit, supporting location of straight brace, friction angle of soil and retaining structure, resultant force action point of earth pressure. Conclusions can be drawn as follows from these curves： axial force and deformation of straight brace will diminish with the increase of displacement of foundation pit, supporting location height of straight brace and friction angle of soil and retaining structure. The height enhancement of resultant force action point of earth pressure will improve axial force and deformation of straight brace. But the initial displacement of the side of foundation pit has no influence on axial force and deformation of straight brace.

关 键 词：支撑 直撑 基坑 土压力 位移 

分 类 号：TU443[建筑科学—岩土工程]