中文摘要：

确定节理峰值抗剪强度公式面临的首要问题是获取节理表面形貌并合理的评价其粗糙度。常用的方法是节理粗糙度系数（JRC）评价方法,但JRC的评价结果是基于二维剖面线获得的,该方法低估了节理面的粗糙度且具有较大的主观性。节理面形貌测试表明,节理面微元有效剪切倾角＊与≥＊的微元面积的总和与节理总面积的比值呈高次抛物线关系。基于42组不同形貌节理的直剪试验结果,将节理的峰值剪胀角与形貌参数相联系,提出新的能够考虑剪胀效应的节理峰值抗剪强度公式。新峰值抗剪强度公式符合莫尔–库仑摩擦定律的形式,具有明确的物理含义。所需要的参数均由节理面形貌测试确定,因此能够预测节理的峰值抗剪强度。最后,对已有的节理峰值抗剪强度公式进行比优统计分析并建议公式的使用范围。

英文摘要：

The major problem in determining the shear strength of rock joints is how to measure and then express the joint roughness with a number or a mathematical function according to joint morphology.Joint roughness coefficient（JRC） is probably the most commonly used method to measure roughness of rock joint surfaces.The method of evaluating JRC of joint is by visual comparison of measured profiles against a set of standard JRC profiles produced by Barton and Choubey.However,JRC estimation by visual comparison is prone to subjectivity and based on the analysis of only a single profile in the direction of shearing and usually underestimates joint roughness.The right method should be based on three-dimensional topography of joint surface.During shear tests,it is observed that the common characteristic among all the contact areas is that they are located in the steepest zones facing the shear direction.There is a parabolic function relationship between the potential contact area and the apparent dip angle.This function is a manifestation of real three-dimensional joint surface morphology information.Based on 42 direct shear test results,the relationship between peak shear dilatancy angle and three-dimensional morphology parameters is presented,and then a new shear strength criterion is proposed.All the parameters are determined according to joint topography.The new criterion follows the standard form of Mohr-Coulomb formula and has a explicit physical meaning.Finally,priority between two shear strength criteria is analyzed and how to use the new criterion is also suggested.