弹塑性条件下岩土孔隙介质有效应力系数理论模型  

Theoretical model of effective stress coefficient for rock/soil-like porous media under elastoplastic condition

作　　者：张凯[1] 周辉[1] 胡大伟[1] 冯夏庭[1] 张元刚[2] 

机构地区：[1]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,武汉430071 [2]兖州煤业股份有限公司,邹城273500

出　　处：《岩土力学》2010年第4期1035-1041,共7页Rock and Soil Mechanics

基　　金：国家自然科学基金委员会;二滩水电开发有限责任公司雅砻江水电开发联合研究基金项目(No.50579091);国家重点基础研究发展规划项目(No.2002CB412708);国家科技支撑计划项目(No.2006BAB04A06)

摘　　要：分析了有效应力系数的物理机理及其主要影响因素,在此基础上,提出了等效孔隙连通率的概念,以此表征岩土类孔隙介质的结构和孔隙之间的连通性,建立了有效应力系数张量演化的普适性理论模型。基于大理岩峰后和砂岩不同塑性变形阶段的有效应力测试试验,分析了塑性条件下影响有效应力系数的主要因素,结果表明塑性条件下,影响有效应力系数的主要因素为等效孔隙连通率。利用试验数据,通过拟合得到了大理岩和砂岩的等效孔隙连通率随应变的演化规律,从而得到了有效应力系数与变形的关系。研究成果为弹塑性条件下的流固耦合研究提供了基础性的理论和方法支持。The research works on effective stress is firstly reviewed in the paper. Physical mechanism and influencing factors on the effective stress coefficient for rock/soil-like porous media are investigated, based on which equivalent connectivity index is proposed to denote the meso-scaled structure of these media. The equivalent connectivity index, relying on the meso-scaled structure of porous media and the property of liquid, denoted the connectivity of the pore in representative element area （REA）. Then a general expression describing the relation between effective stress coefficient tensor and equivalent connectivity tensor of pore is proposed; and the expression can be applied to isotropic media and also to anisotropic media. Based on the effective stress test of marble and sandstone under plastic deformation, the main factors influencing the effective stress coefficient was analyzed; and we found that the main factor is the equivalent connectivity index under the plastic condition. The relation between the equivalent connectivity index and the strain is deduced through fitting of the results of experiment; and then the relation between the effective stress coefficient and strain is obtained. The results can provide an important theoretical support to improve the coupled hydro-mechanical research under elastoplastic condition.

关 键 词：岩土类孔隙介质 有效应力系数张量普适模型 等效孔隙连通率 弹塑性条件 

分 类 号：TU443[建筑科学—岩土工程]