基于方向性粗糙度参数的节理峰值抗剪强度理论模型  

A new theoretical peak shear strength criterion of rock joint based on the directional roughness parameter

作　　者：陈曦 CHEN Xi(Changjiang Survey,Planning,Design and Research Co.,Ltd.,Wuhan,Hubei 430010,China)

机构地区：[1]长江勘测规划设计研究有限责任公司,湖北武汉430010

出　　处：《岩土力学》2023年第4期1075-1088,共14页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.41772308)。

摘　　要：节理裂隙控制着岩石工程的剪切滑移稳定性。现有的节理峰值抗剪强度模型多为经验模型,且较少考虑粗糙节理峰值抗剪强度的采样点距效应及各向异性。采用3D打印技术制备了5组吻合的粗糙光敏树脂节理模具,利用水泥砂浆复制了25组相同壁面强度的人工粗糙节理,开展了5种法向应力水平下节理直剪试验。基于改进的接触面积比-视倾角门槛值关系,建立了仅含一个方向性粗糙度参数的三维粗糙节理峰值抗剪强度理论模型。该理论模型除粗糙度参数外无需拟合其他参数。对比分析发现,新模型比文献中的经验模型预测精度更高。新模型预测效果受采样点距影响较小,且能有效地反映节理峰值抗剪强度的各向异性。The joints within the rock mass control the stability of rock engineering.Most of the existing peak shear strength criteria are empirical models,and the sampling effect and anisotropy of shear strength of rock joints have been rarely reported.A total of 5groups of matched resin molds were prepared based on 3D laser scanning technology and 3D printing technology.A batch of matched mortar joints was duplicated using these molds.A total of 25 groups of the direct shear test were conducted under five constant normal load conditions.A novel theoretical peak shear strength criterion incorporating the newly developed roughness parameters was proposed based on the modified relationship between contact area ratio and threshold apparent dip angles.The proposed criterion was simple and no additional fitting constant was introduced in addition to the roughness parameters.Comparisons between the new criterion and the existing empirical criteria in the literature showed that the new criterion had better accuracy in predicting the shear strength of rock joints.In addition,it was found that the new model was slightly affected by the sampling interval and could capture the anisotropic characteristics of the shear strength of rock joints.

关 键 词：粗糙节理 方向性粗糙度 理论峰值抗剪强度准则 采样点距 各向异性 

分 类 号：TU452[建筑科学—岩土工程]