(1. School of Civil and Environmental Engineering,University of Science and Technology Beijing,Beijing 100083,China;
2. Beijing Zhongguancun Institute of Safety Science Co.,Ltd.,Beijing 100083,China)
Abstract:The stability coefficient of the falling dangerous rock mass is controlled by the depth of the trailing edge crack,and the conventional static calculation method cannot track the dynamic change of the crack depth in real time. How to obtain the current stability coefficient of the dangerous rock in real time is still an urgent problem to be solved. The dynamic equation of a rock beam is established based on the modified Timoshenko beam theory,and the relationship between the bedrock and the dangerous rock mass is compared to the relationship between the Semi-infinite space foundation bed and the foundation. The dynamic constraint boundary of the bedrock to the dangerous rock mass was obtained based on the semi-space theory of the dynamic foundation. Combined with the constraint boundary conditions and the general solution of the dynamic equation,the analytical solution of the natural frequency of the dangerous rock mass is derived,and the quantitative relationship between the natural frequency and the fracture depth of the trailing edge of the dangerous rock mass is established. In order to verify the correctness of the algorithm,the theoretical calculation value is compared with the laboratory test value. The maximum error of the first-order natural frequency under different crack depths is 3.3%,which fully demonstrates the rationality and effectiveness of the natural frequency algorithm of dangerous rock mass. The algorithm is applied to Baoquan Pumped Storage Power Station,and the natural frequency of the dangerous rock mass is successfully obtained through the measurement of constant time fretting. After calculation,the fracture depth of the rear edge of the current dangerous rock mass is obtained,and the stability coefficient of the current dangerous rock mass is calculated. Practice has proved that the natural frequency of the dangerous rock mass is measurable,which provides a theoretical reference for the realization of automatic monitoring of collapse and has theoretical and market prospective.
张晓勇1,2,谢谟文1,2,张 磊1,2,杜 岩1,刘卫南1,高世崇1. 基于固有频率的坠落危岩体稳定系数计算模型研究[J]. 岩石力学与工程学报, 2023, 42(3): 585-593.
ZHANG Xiaoyong1,2,XIE Mowen1,2,ZHANG Lei1,2,DU Yan1,LIU Weinan1,GAO Shichong1. Study on calculation model of stability coefficient of falling dangerous rock mass based on natural frequency. , 2023, 42(3): 585-593.
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