岩石统一能量屈服准则  

UNIFIED ENERGY YIELD CRITERION OF ROCK

作　　者：周辉[1] 李震[1] 杨艳霜[1] 张传庆[1] 盛谦[1] 

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,湖北武汉430071

出　　处：《岩石力学与工程学报》2013年第11期2170-2184,共15页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家重点基础研究发展计划(973)项目(2014CB046902);中国科学院知识创新工程重要方向项目(KZCX2–EW–QN115);国家自然科学基金项目(41172288);国家自然科学基金重大研究计划集成项目(91215301)

摘　　要：不同于金属材料,岩石材料由于具有内摩擦特性而表现出明显的Lode角效应等特点,其屈服过程不仅与广义剪应力有关,还受静水压力的影响。为建立适用范围更广、更符合岩石屈服机制的屈服准则,开展如下主要工作:综合考虑岩石材料屈服时的剪切滑移和法向压密机制,将与屈服相关的能量划分为3个复合滑动面的剪切应变能之和与体积应变能,并给出相应的计算公式;几种不同性质的岩石试验结果表明,岩石屈服时的2种能量近似符合线性关系,基于此,建立岩石统一能量屈服准则,总体上它可较好地描述岩石材料的屈服特性,如子午面上的曲线形态、Lode角效应等;通过对常用的岩石屈服准则进行对比分析,指出统一能量屈服准则是多种常用岩石屈服准则的一般形式;分别采用统一能量屈服准则、三剪能量屈服准则、Mohr-Coulomb屈服准则、Drucker-Prager屈服准则、双剪强度理论、Hoek-Brown准则和Murrell准则对3种不同性质岩石的屈服强度进行计算,结果表明统一能量屈服准则的计算结果比较精确(尤其是在高围压和高静水压力条件下),并且分析统一能量屈服准则产生上述结果的本质机制,探讨岩石材料屈服时剪切应变能为定值的传统假设近似成立的条件。所建立的岩石统一能量屈服准则突破了岩石材料屈服时剪切应变能为定值的传统假设,通过分析体积应变能对岩石屈服的影响规律,在屈服准则中合理地考虑体积应变能的影响因素,这对于准确地定量分析岩石材料的屈服特性具有重要意义。Unlike metals, rock materials show the Lode angle dependence and other characters in mechanical behavior as a result of frictional effect. Its yield process depends not only on generalized shear stress but also on hydrostatic pressure. In order to construct the unified yield criterion which is widely used and accordant with characters of rock, work and results are as follows. Firstly, considering shear slide and normal compaction, energy related to yield is divided into the sum of shear strain energy on combined mobilized plane together with volumetric strain energy and their formulas are also derived. Secondly, test results show that when rock yields the relationship between the two kinds of strain energy is linear. Based on the result, rock unified yield criterion is established and it can describe basic yield characters such as curves on meridian plane and Lode angle dependence Thirdly, after the analysis of some widely used rock yield criterions, it is proposed that unified energy yield criterion is a generalized form of these yield criterions. Lastly, the yield strength is calculated and with the following criterions respectively： the unified energy yield criterion, the triple shear energy yield criterion, Molar-Coulomb yield criterion, Drucker-Prager yield criterion, twin-shear strength theory, Hoek-Brown yield criterion and Murrell yield criterion. The result by the unified energy yield criterion is more accurate and the error is more stable as well especially under high confining pressure and hydrostatic pressure. The intrinsic mechanism of above-mentioned result is analyzed and the qualification of the traditional assumption that shear strain energy retains to be constant when rock yields is confirmed. So the unified energy yield criterion established in this paper breaks through the traditional assumption. The factor such as volumetric strain energy should be considered reasonably in the yield criterion by analyzing the influencing rule of it, which is significant for the accurate quantitative analysi

关 键 词：岩石力学 岩石材料 统一能量屈服准则 剪切应变能 体积应变能 

分 类 号：TU45[建筑科学—岩土工程]