砂土充填大理岩节理的剪切强度经验公式

为研究砂土充填对节理抗剪强度的影响，利用GCTS（RDS?200型）岩石剪切测试系统对4种不同摩擦系数砂土充填的粉晶大理岩节理进行了直剪试验。结果表明：相同法向应力下，未充填节理的峰值剪切应力大于充填节理的峰值剪切应力，说明砂土的存在降低了节理的剪切强度；由节理面三维形貌参数最大谷深 表征节理面粗糙程度，得到了未充填节理的峰值剪切强度公式，公式预测值与试验值基本吻合；得到了用充填砂土摩擦系数表达的充填节理峰值剪切强度公式，公式预测值与试验值较为吻合。研究结论对充填节理岩体稳定性评价具有一定指导意义。

Empirical formula for shear strength of marble joints infilled with sands

To investigate the effect of sandy fillings on the shear strength of rock joints, direct shear tests were conducted on single-joint fine-grained marble specimens infilled with four types of sands with different frictional coefficients. The results show that the peak shear stress of unfilled marble joints was greater than those of infilled marble joints under a same normal stress. It is indicated that the existence of sandy fillings reduced the shear strength of rock joints. A new empirical formula for the shear strength of the unfilled joints was proposed, expressed by the three-dimensional roughness parameter of maximum valley depth of the joint surfaces, and its calculated shear strength of the unfilled joints roughly coincided with their test values. An empirical formula of peak shear strength for infilled fine-grained marble joints was also obtained, expressed by the friction coefficients of infilled sands. the predicted shear strength of infilled rock joints was in accordance with the test values. Above conclusions have some helps to evaluate the stability of infilled jointed rock mass in rock engineering.