考虑尺寸效应的岩石损伤统计本构模型研究  

STUDY ON STATISTICAL DAMAGE CONSTITUTIVE MODEL OF ROCK CONSIDERING SCALE EFFECT

作　　者：杨圣奇[1] 徐卫亚[1] 苏承东[2] 

机构地区：[1]河海大学岩土工程研究所,江苏南京210098 [2]河南理工大学资源与材料工程系,河南焦作454159

出　　处：《岩石力学与工程学报》2005年第24期4484-4490,共7页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(50128908);江苏省高等学校研究生创新计划项目资助课题(xm04–39)

摘　　要：基于岩石的应变强度理论和岩石强度的随机统计分布假设,采用损伤力学理论,考虑微元体破坏及弹性模量与尺寸之间的非线性关系,建立了单轴压缩下考虑尺寸效应的岩石损伤统计本构模型。然后采用伺服试验机对不同尺寸大理岩石进行了单轴压缩试验研究,得到了不同尺寸大理岩样试验结果;讨论了材料力学参数与尺寸之间的关系,给出了考虑尺寸效应的岩石损伤统计本构模型参数。预测的不同尺寸岩石理论曲线和试验结果相比较,显示了所建模型的合理性。最后探讨了岩石尺寸对损伤特性的演化规律。The stress-strain curve of rock with a given size is only a kind of macroscopical manifestation, which can not be applied directly to the design of geotechnical engineering and the analysis of numerical computation, i.e., there is an indiscerptible relation between constitutive model and size of rock, which is not clearly understood. Based on the strain strength theory and the random statistical distribution hypothesis of rock strength, a statistical constitutive model for rock damage under uniaxial compression, which considers the nonlinear relation of unit volume failure or elastic modulus and the size, is established by adopting the damage constitutive theory of continuous medium. With the servo-controlled testing machine, uniaxial compressive experiment is performed on the marble specimens with different ratios of length to diameter. On the basis of experimental results of marble specimens with different sizes, the relation between mechanical parameters of rock material and size is discussed： and then the parameters for statistical damage constitutive model of rock considering scale effect are confirmed. The achieved theoretical curves by the damage model of rock with different ratios of length to diameter ratios are in good agreement with the experimental results. Finally, the evolution law of rock scale on the damage properties is discussed.

关 键 词：岩石力学 尺寸效应 损伤 统计 本构模型 损伤变量 

分 类 号：TU452[建筑科学—岩土工程] O346.5[建筑科学—土工工程]