摘要
考虑结构面抗剪强度震动退化效应对分析与评价岩质边坡动力稳定性具有重要意义。基于岩石动力试验获取了多因素影响的结构面强度震动退化系数方程,结合极限平衡理论和动态矢量法原理,以UDEC程序作为计算引擎,采用其内置Fish语言编程实时刷新结构面强度特性参数和捕获任意地震历时时刻边坡地震惯性力,并以最小平均安全系数法求解边坡最终动力稳定性评价指标值,从而提出了一种考虑结构面强度震动退化的边坡动力稳定性系数动态算法。研究表明:结构面强度震动退化系数是取决于岩块间循环剪切次数、循环剪切幅度及相对运动速度响应值的动态变量;将该算法应用于含贯通型平直状结构面边坡动力稳定性算例中,其分析结果表明,动力作用时程内考虑结构面强度震动退化的边坡动力稳定性系数较未考虑该效应时的系数衰减更为明显,即前者计算结果更符合一般性自然规律,亦即验证了该算法的可行性;结构面最小强度震动退化系数随动力激励时程变化近似呈负指数函数形式逐渐衰减,且当结构面初始黏聚力(内摩擦角)越大、而坡角(层面倾角)或动荷载幅值(频率)越小时,地震历时过程中边坡最小动力稳定性系数越大,此时边坡最终动力稳定性相对越强。
The shear strength vibration degradation of the rock discontinuities is of great significance to analyze and evaluate the dynamic stability of rock slope.Based on the rock dynamic test,the strength vibration degradation coefficient equation of the rock discontinuities affected by multiple factors was obtained.Then,combined with the limit equilibrium theory and the principle of dynamic vector method,the UDEC program was used for calculation,and its built-in Fish language was used to program to update the strength characteristic parameters of the rock discontinuities in real time and capture the seismic inertia force of slope at any time of earthquake duration,and the minimum average safety coefficient method was adopted to solve the final dynamic stability evaluation index.Thereby,a dynamic algorithm of slope dynamic stability coefficient considering the strength vibration degradation of the rock discontinuities was proposed.The results show that:(1)The strength vibration degradation coefficient of the rock discontinuities is a dynamic variable that depends on the response value of the number and amplitude of cyclic shearing and the relative motion speed between rock blocks.(2)The algorithm is applied to the calculation example of the dynamic stability of slope with the through-type and straight rock discontinuities.The analysis results show that in the dynamic action time history,the attenuation of the dynamic stability coefficient of slope considering the strength vibration degradation of the rock discontinuities is more obvious than that without considering the effect,i.e.the calculation results of the former are more in line with the actual observation,which verify the feasibility of the proposed algorithm.(3)The minimum strength vibration degradation coefficient of the rock discontinuities decays gradually in the form of negative exponential function with the time-history change of dynamic excitation.The larger the initial cohesion(internal friction angle)of the rock discontinuities is,the smaller the slope angle(layer inclination)or dynamic load amplitude(frequency)is,the larger the minimum dynamic stability coefficient of slope during the earthquake duration is,and the relatively stronger the final dynamic stability of slope is at this time.
作者
许彬
刘新荣
周小涵
梁越
钟祖良
刘俊
邓志云
XU Bin;LIU Xin-rong;ZHOU Xiao-han;LIANG Yue;ZHONG Zu-liang;LIU Jun;DENG Zhi-yun(School of River and Ocean Engineering,Chongqing Jiaotong University,Chongqing 400074,China;Key Laboratory of Hydraulic and Waterway Engineering of the Ministry of Education,Chongqing Jiaotong University,Chongqing 400047,China;School of Civil Engineering,Chongqing University,Chongqing 400045,China;National Engineering Research Center for Inland Waterway Regulation,Chongqing Jiaotong University,Chongqing 400074,China;China Construction Second Engineering Bureau Ltd.,Beijing 100160,China;Department of Hydraulic Engineering,Tsinghua University,Beijing 100084,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2023年第8期2419-2431,2470,共14页
Rock and Soil Mechanics
基金
中国博士后科学基金(No.2023M730432)
重庆市博士后特别资助项目(No.2022CQBSHTB1010)
重庆市博士后科学基金(No.CSTB2023NSCQBHX0223)
国家内河航道整治工程技术研究中心暨水利水运工程教育部重点实验室开放基金(No.SLK2023A03)
重庆交通大学博士后科学基金(No.22JDKJC-A008)。
关键词
结构面
强度震动退化
数值实现
边坡动力稳定性
影响因素
rock discontinuities
strength vibration degradation
numerical realization
dynamic stability of slope
influence factor
作者简介
第一作者:许彬,男,1993年生,博士后,主要从事岩土力学与边坡工程等方面的科研工作。E-mail:geotechnicale2016@163.com;通讯作者:刘新荣,男,1969年生,博士,教授,博士生导师,主要从事岩土力学与边坡工程等方面的教学与科研工作。E-mail:liuxrong@126.co。
