考虑非平稳趋势向影响的结构面抗剪强度模型研究  

Study on the shear strength model of rock joints considering the influence of non-stationary trend

作　　者：刘维明 王昌硕 张希巍[3] 雍睿[1] 罗战友 杜时贵 LIU Weiming;WANG Changshuo;ZHANG Xiwei;YONG Rui;LUO Zhanyou;DU Shigui(Institute of Rock Mechanics,Ningbo University,Ningbo,Zhejiang 315211,China;The Engineering Research Center of Rock-Soil Drilling and Excavation and Protection,Ministry of Education,China University of Geosciences(Wuhan),Wuhan,Hubei 430074,China;Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines,Northeastern University,Shenyang,Liaoning 110819,China)

机构地区：[1]宁波大学岩石力学研究所,浙江宁波315211 [2]中国地质大学(武汉)、岩土钻掘与防护教育部工程研究中心,湖北武汉430074 [3]东北大学、深部金属矿山安全开采教育部重点实验室,辽宁沈阳110819

出　　处：《岩石力学与工程学报》2023年第2期378-390,共13页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(42177117);浙江省自然科学基金资助项目(LQ16D020001);中国地质大学(武汉)岩土钻掘与防护教育部工程研究中心开放基金资助项目(202205)。

摘　　要：结构面非平稳趋势向(结构面与剪切平面之间的夹角)的存在直接影响结构面试样抗剪强度评价的准确性。现有抗剪强度计算模型未考虑结构面非平稳趋势向的影响,不适用于趋势向非平稳的结构面抗剪强度计算。为此,在定量表征结构面趋势向α和β(α为结构面沿剪切方向的倾角,β为结构面沿垂直于剪切方向的偏转角)的基础上,以结构面最小二乘拟合平面为参考平面,将外部施加的法向、切向应力分解为参考平面的法向、切向应力,并据此建立考虑非平稳趋势向影响的结构面抗剪强度模型,采用数值解析法计算该模型的数值解,通过直剪试验对数值解的准确性进行验证。研究结果表明:结构面抗剪强度主要受趋势向α控制,而趋势向β对抗剪强度的影响比重小于1.5%,计算时可忽略不计;抗剪强度的改进值相对其原型值的误差上下限随法向应力的增大而增大、随结构面三维粗糙度JRC3D的增大而增大;相较于未考虑趋势向影响的抗剪强度模型,改进模型计算得出的抗剪强度的准确率分别提高了24.45%,23.693%,25.37%,14.504%,所提出的结构面抗剪强度模型可有效评价含非平稳趋势向的结构面抗剪强度,为岩体结构面抗剪强度的估算奠定了理论基础。The existence of the non-stationary trend of rock joint(the angle between the rock joint and the shear plane)directly affects the accuracy of the shear strength evaluation of the rock joint specimen.The existing shear strength calculation models do not consider the influence of the non-stationary trend of rock joint and are not suitable for the calculation of the shear strength of the rock joint with non-stationary trend.To do this,this paper quantitatively characterizes the trend directionsαandβof the rock joint(αandβrepresenting the inclination angle of the rock joint along the shearing direction and the deflection angle of the rock joint perpendicular to the shearing direction).The least square fitting plane of the rock joint is taken as the reference plane,the external normal and tangential stresses are decomposed into the normal and tangential stresses of the reference plane,a shear strength model of the rock joint considering the influence of non-stationary trend is established based on this.The numerical solution of the model is calculated by numerical analysis method,and the accuracy of the numerical solution is verified by direct shear test.The research results show that the shear strength of rock joint is mainly controlled by the trendα,while the influence of the trendβon the shear strength is less than 1.5%,which can be ignored in the calculation;The upper and lower error limits between the improved value of shear strength and its prototype value increase with the increase of the normal stress and the three-dimensional roughness JRC3D of the rock joint;Compared with the shear strength model without considering the influence of non-stationary trend,the accuracy of the shear strength calculated by the improved model is increased by 24.45%,23.693%,25.37%and 14.504%respectively,the proposed shear strength model can effectively evaluate the shear strength of the rock joint specimen with nonstationary trend,which lays a theoretical foundation for the evaluation of shear strength of rock joint.

关 键 词：岩石力学 结构面 粗糙度 抗剪强度 非平稳趋势向 直剪试验 

分 类 号：TU45[建筑科学—岩土工程]