基于三维形貌特征的岩石节理峰值剪切强度准则研究

Peak shear strength criterion for rock joints based on three-dimensional morphology characteristics

引入3个在一定范围内独立于测量尺度的三维形貌参数表征岩石节理形貌,并基于形貌参数建立了新的岩石节理峰值剪切强度准则。同时采用新准则和Barton公式计算了23对岩石节理的峰值剪切强度并与室内直剪试验结果对比,新准则的计算值与试验结果较为接近而Barton公式在一定程度上低估了节理剪切强度,表明新准则能更好地描述节理峰值剪切强度。新准则的三维形貌参数反映了不同形貌特征对剪切强度的贡献,物理意义明确,并且形貌参数可在一定范围内采用任意尺度测量,因而有利于新准则的工程应用。进一步分析表明:在规则齿形节理情况下,新准则可退化到Patton公式的形式,因而新准则实质是Patton公式的三维推广。

Three 3D morphology parameters independent of measurement scale within limits are introduced to characterize the morphology characteristics of rock joints, and a new peak shear strength criterion for the rock joints is developed based on the morphology parameters. Then, both the new criterion and Barton＇s criterion are adopted to calculate the peak shear strength of 23 pairs of rock joints. By comparing the calculated and tested peak shear strengths, the new criterion is proved to be more reasonable, while the peak shear strength calculated by Barton＇s formula is underestimated. The new criterion has a clear physical meaning because the contribution of different morphology characteristics to the peak shear strength is represented in detail by the three morphology parameters, and it is also convenient for the new criterion to be applied to engineering practice since the morphology parameters can be measured by any scale within some limits. Furthermore, the new criterion is essentially the generalized 3D form of Patton＇s criterion as it can be simplified to Patton＇s formula when applied to regular joints.