考虑材料剪胀及软化的扩孔问题的统一解  

Unified Solution on Expansion Cavity Considering Material Dilatancy and Softening

作　　者：范文[1] 廖红建[1] 陈立伟[2] 

机构地区：[1]西安交通大学建筑工程与力学学院,西安710049 [2]长安大学国土资源部岩土工程开放研究实验室,西安710054

出　　处：《西安交通大学学报》2003年第9期957-961,共5页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金资助项目(50149017);国土资源部岩土工程开放研究实验室资助项目(KF011).

摘　　要：基于统一强度理论,考虑孔周岩土材料的软化特性、剪胀特征,详细推导了柱形孔扩孔问题的统一解公式,并给出了临界扩孔压力及扩孔压力与孔周岩土体所处状态的关系,导出了孔周岩土体内应力、位移等的解析公式.通过实例分析认为,在给定软化模型下,临界扩孔压力及塑性软化区半径随剪胀性的增大而增大;在一定剪胀程度下,临界扩孔压力随软化程度的减小而增大;在一定剪胀及软化程度下,临界扩孔压力随材料参数b值的增大而增大.讨论了软化、剪胀及强度模型对扩孔压力及孔周岩土体内应力场和位移场的影响,认为剪胀性对孔周应力场的影响不大,孔壁位移随剪胀性的增大而减小;软化性对孔周应力场和位移场的影响较复杂;不同强度模型对孔周位移场及孔壁位移影响不大,但对扩孔压力影响较大.Based on the unified strength theory, the unified formula considering the characteristics of softening and dilatation of geomaterial around the cylindrical cavity is deduced. The relationship between the expansion pressure and the state of the geomaterial around the cavity is constructed, and the analytic formulae of peripheral stress and displacement are applied to some practical cases. It can be concluded that if other conditions are the same, the critical expansion pressure and the plastic softening zone expand with the increasing shearing-dilatation, and under some conditions the critical expansion pressure increases as the softening decreases or as the material parameter b increases. Furthermore, the influences of softening, shearing-dilatation and strength criteria on the expansion pressure, the stress field and the displacement field are discussed. The results show that the displacement of the cavity wall increases as the dilatancy decreases; the softening has complicated effect on the stress and displacement field of the geomaterial around the cavity; different strength models have great influence on the expansion pressure.

关 键 词：统一强度理论 扩孔 软化 剪胀 

分 类 号：TU452[建筑科学—岩土工程]