The characteristics of a disturbed soil-structure interface were studied based on the variation regularities of the disturbed soil within its mining subsidence area using direct shear tests.The effects of the initial ...The characteristics of a disturbed soil-structure interface were studied based on the variation regularities of the disturbed soil within its mining subsidence area using direct shear tests.The effects of the initial moisture content on the shear strength parameters of the soil-structure interfaces were analyzed.The results indicate that the cohesion of the interface initially increased and then decreased as the initial moisture content increased.In addition,the friction angle of the interface decreased as the initial moisture content increased.A constitutive model of the disturbed soil-structure interface,a rigid-plastic model based on the initial void ratio and saturability(VSRP) model,was established based on the results.In order to validate this model,a finite element analysis of DRS-1 direct shear tests was conducted.The finite element model calculations coincided with the results of the DRS-1 direct shear tests.The proposed model also reflected the nonlinear features of the soil-structure interface.展开更多
为从宏、细观角度揭示常法向刚度(Constant Normal Stiffness,CNS)条件下锯齿状砂岩-混凝土结构面剪切机制,首先采用湖南大学自主改造的CNS岩石直剪仪开展3组砂岩-混凝土结构面室内剪切试验.在此基础上,采用刚性墙替代法建立与室内试验...为从宏、细观角度揭示常法向刚度(Constant Normal Stiffness,CNS)条件下锯齿状砂岩-混凝土结构面剪切机制,首先采用湖南大学自主改造的CNS岩石直剪仪开展3组砂岩-混凝土结构面室内剪切试验.在此基础上,采用刚性墙替代法建立与室内试验相应的离散元数值模型,并引入3个显式运动学方程控制砂岩试样运动轨迹从而实现CNS条件加载,将数值模拟与试验结果对比验证了模型的合理性.随后,开展16个工况的数值剪切试验,通过观察剪切裂纹扩展和力链演化形态,从细观角度揭示结构面破坏模式和荷载传递机制,并从宏观角度分析锯齿几何尺寸(半波长λ、起伏角θ)和加载边界条件(初始法向应力σn0、法向刚度K)对剪切强度和法向膨胀的影响.结果表明:剪切裂纹按照“平稳增加—急剧增加—增幅减小”的发展趋势由结构面区域逐渐向岩石内部扩展,结构面破坏模式随起伏角的增大由滑移磨损向剪断破坏过渡,剪切强度随λ、θ、σn0和K的增加呈指数函数型增加.展开更多
基金Project(51274192)supported by National Natural Science Foundation of China
文摘The characteristics of a disturbed soil-structure interface were studied based on the variation regularities of the disturbed soil within its mining subsidence area using direct shear tests.The effects of the initial moisture content on the shear strength parameters of the soil-structure interfaces were analyzed.The results indicate that the cohesion of the interface initially increased and then decreased as the initial moisture content increased.In addition,the friction angle of the interface decreased as the initial moisture content increased.A constitutive model of the disturbed soil-structure interface,a rigid-plastic model based on the initial void ratio and saturability(VSRP) model,was established based on the results.In order to validate this model,a finite element analysis of DRS-1 direct shear tests was conducted.The finite element model calculations coincided with the results of the DRS-1 direct shear tests.The proposed model also reflected the nonlinear features of the soil-structure interface.
文摘为从宏、细观角度揭示常法向刚度(Constant Normal Stiffness,CNS)条件下锯齿状砂岩-混凝土结构面剪切机制,首先采用湖南大学自主改造的CNS岩石直剪仪开展3组砂岩-混凝土结构面室内剪切试验.在此基础上,采用刚性墙替代法建立与室内试验相应的离散元数值模型,并引入3个显式运动学方程控制砂岩试样运动轨迹从而实现CNS条件加载,将数值模拟与试验结果对比验证了模型的合理性.随后,开展16个工况的数值剪切试验,通过观察剪切裂纹扩展和力链演化形态,从细观角度揭示结构面破坏模式和荷载传递机制,并从宏观角度分析锯齿几何尺寸(半波长λ、起伏角θ)和加载边界条件(初始法向应力σn0、法向刚度K)对剪切强度和法向膨胀的影响.结果表明:剪切裂纹按照“平稳增加—急剧增加—增幅减小”的发展趋势由结构面区域逐渐向岩石内部扩展,结构面破坏模式随起伏角的增大由滑移磨损向剪断破坏过渡,剪切强度随λ、θ、σn0和K的增加呈指数函数型增加.
