岩石统计损伤本构模型与试验  

The statistical damage constitutive model of rocks and its experiment

作　　者：王苏生 徐卫亚[1,2] 王伟[1,2] 王如宾[1,2] 向志鹏[1,2] WANG Susheng XU Weiya WANG Wei WANG Rubin XIANG Zhipeng(Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering, Hohai University , Nanjing 210098, China Institute of Geotechnical Engineering, Hohai University, Nanjing 210098, China)

机构地区：[1]河海大学岩土力学与堤坝工程教育部重点实验室,江苏南京210098 [2]河海大学岩土工程科学研究所,江苏南京210098

出　　处：《河海大学学报（自然科学版）》2017年第5期464-470,共7页Journal of Hohai University(Natural Sciences)

基　　金：国家自然科学基金(11172090)

摘　　要：基于Mohr-Coulomb破坏准则以及岩石微元强度服从Weibull函数随机分布假设,通过有效应力原理引入孔隙水压力,构建了新的统计损伤本构模型,该模型可以考虑孔隙体积变化和损伤阀值的影响。此外,提出了一种新的岩石微元强度计算方法。为使模型参数具有明确的物理意义,采用应力~应变曲线峰值点强度确定模型参数m和F0。采用砂岩常规三轴压缩试验对本构模型的合理性进行验证,并在此基础上,分析岩石损伤演化、孔隙率变化规律,探讨围压对模型参数的影响。结果表明,该模型能够较好地反映岩石三轴应力~应变关系。Based on the Mohr-Coulomb failure criterion and the hypothesis of the rock micro-unit strength subject to Weibull random distribution, a new statistical damage constitutive model is established by introducing the pore water pressure by means of the effective stress theory. The new model can consider the influences of both pore volume change and damage threshold. In addition, a novel micro-unit strength calculation method for the rock is proposed. In order to make the model parameters have definite physical meaning, the model parameters m and Fo are determined by using the peak point strength in the stress strain curve. In this study, the conventional triaxial compression tests for sandstone are conducted to verify the rationality of the model, by which the damage evolution and porosity variation of the rock under different confining pressures are analyzed, and the effects of confining pressures on the model parameters are explored. The findings show that the model can well reflect the relationship between triaxial stress and strain of the rock.

关 键 词：岩石力学 MOHR-COULOMB准则 WEIBULL分布 微元强度 统计损伤模型 

分 类 号：TU452[建筑科学—岩土工程]