基于颗粒流直剪试验的结构面细观颗粒运移规律研究

On Size Effect of Rock Joints Roughness Based on Varied Statistical Methods

岩石内部的结构面在自然外力作用下对岩石的力学性质和变形破坏都有至关重要的作用,影响着岩土工程的安全稳定性.基于颗粒流理论,根据节理粗糙度(JRC)标准剖面轮廓曲线,建立赋予颗粒相应的细观结构参数的岩样颗粒流模型.通过对试样进行不同法向应力下的直剪模拟试验,结果表明:微裂纹数量随着法向应力和JRC的增加而增加,且在达到峰值剪切强度时迅速增加.试样一般表现为拉剪混合破坏,试样下半部颗粒单元的运移程度随着试样受到法向应力的增加而减小,且颗粒运移量沿着加载方向逐渐减小,颗粒运移差量比较大的地方容易产生裂纹.同时受不同节理粗糙度的影响在不同位置都形成了稀疏带,在稀疏区域会产生潜在的裂隙.研究所得结果可以为工程应用提供一定的参考价值和理论依据.

Under natural external force,the internal structural plane of rocks plays an important role in mechanical properties and deformation failures,thereby affecting the safety and stability of geotechnical engineering.On the basis of particle flow theory,a particle flow model of a rock sample was established corresponding the mesoscopic structural parameters of the particles,and combined with the standard profile contour curve of the joint roughness coefficient(JRC).The results of a direct shear simulation test under different normal stresses on the sample show that the microcracks increase as a function of normal stress and JRC and increase rapidly when the peak shear strength is reached.The specimen generally exhibits mixed tensile-shear failures,and the migration degree in the particle unit of the lower half of the specimen is reduced as the normal stress increases.The particle migration capacity gradually decreases along the loading direction.Cracks are likely to occur in locations where the particle migration difference is relatively large,and sparse zones are produced at different positions because of the influence of different joint roughness.The experimental results of this paper can provide certain reference and theoretical basis for engineering applications.