深部岩石考虑残余强度时三轴试验离散元定量模拟及参数分析  

Quantitative simulation of triaxial test considering residual strength on deep rock using DEM and parameter analysis

作　　者：李磊[1,2,3] 蒋明镜 张伏光[1,2,3] LI Lei1,2,3, JIANG Ming-jing1,2,3, ZHANG Fu-guang1,2,3(1. State Key Laboratory for Disaster Reduction in Civil Engineering, Tongji University, Shanghai 200092, China; 2. Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, Tongji University, Shanghai 200092, China; 3. Department of Geotechnical Engineering, Tongji University, Shanghai 200092, Chin)

机构地区：[1]同济大学土木工程防灾国家重点实验室,上海200092 [2]同济大学岩土及地下工程教育部重点实验室,上海200092 [3]同济大学地下建筑与工程系,上海200092

出　　处：《岩土力学》2018年第3期1082-1090,1099,共10页Rock and Soil Mechanics

基　　金：国家重点基础研究发展规划(973)项目(No.2014CB046901)~~

摘　　要：深部岩石在工程中具有高应力、大变形等典型特点,因此,高围压下考虑岩石残余强度的三轴试验对于分析深部岩石力学特性具有重要意义。离散单元法是分析岩石力学特性的重要数值方法,但是长期以来采用离散单元法定量模拟岩石的三轴试验一直存在诸多挑战,即数值模拟与室内试验得到的应力-应变全过程曲线难以定量匹配。采用改进的三维胶结抗弯-扭模型对深部砂岩考虑残余强度时的三轴试验进行了定量模拟,实现了数值模拟与室内试验应力-应变全过程曲线的定量匹配,获得了岩石较大的峰值/残余内摩擦角及非线性强度包线,克服了经典BPM模型存在的3个突出问题。通过参数分析,研究了峰值/残余内摩擦角及黏聚力与离散元微观参数之间的关系,同时这些大量的算例也证明了该模型具有较高的计算效率,可以满足模拟三维室内常规试验的要求。Deep rock is characterised by high stress and large deformation in underground engineering. It is of great significance to investigate its mechanical properties by conducting the triaxial tests under high confining pressure and considering a residual strength. The distinct element method（DEM） is an essential numerical method for analysing the mechanical properties of rock. However, there have been many challenges in quantitatively simulating the rock by DEM in the triaxial tests. The reason is that it is challenging to quantitatively reproduce the complete stress-strain curves of rock using DEM. By considering the residual strength of rock, the triaxial compression tests on deep sandstone were quantitatively simulated by DEM using the improved three-dimensional（3 D） bond model incorporating rolling and twisting resistance. The results show that this study successfully achieves the quantitative reproducing of the complete stress-strain curves. The large peak/residual internal friction angle and nonlinear strength envelope of rock are obtained as well. Meanwhile, this study overcomes three prominent challenges of the classic bonded-particle model（BPM）. The relationships among the peak/residual internal friction angle, cohesion and microscopic parameters of DEM are discussed through a large number of simulations. At the same time, the high computational efficiency is proved using the improved model, which can satisfactorily meet the requirements of the 3 D simulation for conventional laboratory tests.

关 键 词：深部岩石 残余强度 三轴试验 定量模拟 离散单元法 参数分析 

分 类 号：TU411[建筑科学—岩土工程]