刘帅奇, 马凤山, 赵海军, 刘港, 郭捷, 孙琪皓. 2018: 基于RJM断续节理岩体强度与破坏特征的数值模拟研究. 工程地质学报, 26(5): 1342-1350. DOI: 10.13544/j.cnki.jeg.2018250
    引用本文: 刘帅奇, 马凤山, 赵海军, 刘港, 郭捷, 孙琪皓. 2018: 基于RJM断续节理岩体强度与破坏特征的数值模拟研究. 工程地质学报, 26(5): 1342-1350. DOI: 10.13544/j.cnki.jeg.2018250
    LIU Shuaiqi, MA Fengshan, ZHAO Haijun, LIU Gang, GUO Jie, SUN Qihao. 2018: RJM BASED NUMERICAL STUDY OF STRENGTH AND FAILURE MODES OF ROCKMASS WITH DISCONTINUOUS JOINTS. JOURNAL OF ENGINEERING GEOLOGY, 26(5): 1342-1350. DOI: 10.13544/j.cnki.jeg.2018250
    Citation: LIU Shuaiqi, MA Fengshan, ZHAO Haijun, LIU Gang, GUO Jie, SUN Qihao. 2018: RJM BASED NUMERICAL STUDY OF STRENGTH AND FAILURE MODES OF ROCKMASS WITH DISCONTINUOUS JOINTS. JOURNAL OF ENGINEERING GEOLOGY, 26(5): 1342-1350. DOI: 10.13544/j.cnki.jeg.2018250

    基于RJM断续节理岩体强度与破坏特征的数值模拟研究

    RJM BASED NUMERICAL STUDY OF STRENGTH AND FAILURE MODES OF ROCKMASS WITH DISCONTINUOUS JOINTS

    • 摘要: 裂隙结构的存在对于工程岩体的强度和稳定性具有重要影响,岩石宏观裂隙的产生源自于微破裂的积累。针对岩体裂隙的粗糙特性,通过Matlab建立考虑粗糙度的节理模型(Roughness Joint Model),采用简化的正弦曲线来表示粗糙节理,并将其导入到颗粒流试验模型中进行单轴压缩试验。对比完整岩体、直线型裂隙岩体、RJM岩体三者破坏的应力-应变曲线,改变裂隙倾角(与水平方向夹角)α,岩桥倾角β,裂隙密度γ,建立不同裂隙分布的断续节理岩体数值试样,开展一系列数值模拟试验。研究结果发现:(1)裂隙的存在明显降低了岩体的抗压强度,RJM模型峰值强度和峰值应变均高于直线型裂隙岩体;(2)岩体抗压强度总体上随裂隙倾角增大而增加,随裂隙密度增加而减小,但随岩桥倾角的改变呈非线性变化,岩桥倾角45°时峰值强度最低,峰值应变最小;(3)裂隙分布会影响岩体的破裂模式,微裂隙的扩展反映了岩体力学性质的各向异性;(4)不同倾角下增加裂隙密度,岩体强度下降程度不同,倾角75°时密度对强度影响最小,30°和60°时影响最大。

       

      Abstract: The Roughness Joint Model(RJM)considering JRC is established in Matlab program. Simplified sinusoidal curves are used to represent roughness joints. Then it is introduced into the Particle Flow Code to conduct the uniaxial compression test. We compare the stress-strain curves of intact rock mass, linear fractured rock mass and RJM rock mass, and change the fracture inclination(angle with horizontal direction)α, rock bridge angle β, fracture density γ. Then numerical models of fractured rock mass with different fracture distributions are established to conduct a series of numerical simulation tests. By monitoring the initiation and propagation of secondary fractures, the damage process of jointed rock is analyzed. Findings can be drawn as follows. (1)The presence of fractures significantly reduces the strength of rock mass. The peak strength and peak strain of RJM model are higher than those of linear cracks. (2)The compression strength of rock mass increases with the increase of joint inclination and decreases with the increase of fracture density, but changes in a nonlinear law with the fracture bridge angle. The peak strength at rock bridge inclination angle of 45°is the lowest, peak strain is the minimum. (3)The distribution of fractures has influence on failure mode, The expansion of the micro-fissures reflects the anisotropy of the mechanical properties of the rock mass. (4)Increasing the fracture density at different dip angles can reduce the strength of the rock mass in different level. When the dip angle is 75°, the density has the least influence on the strength, but at 30° and 60° the influence is the greatest.

       

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