Analysis of removability and stability of rock blocks by considering the rock bridge effect

In traditional block theory, the removability and stability of rock blocks are analyzed independently; that is, the stability of a removable block is analyzed in detail, and nonremovable blocks are regarded as stable. However, in practical situations, nonremovable blocks may pose more danger than removable blocks. This paper presents a unified method for analyzing the removability and stability of rock blocks. In this method, the cracking of rock bridges is considered and nonremovable blocks are not assumed to be stable. First, possible cracking rock bridges are identified by extending finite-sized fractures and comparing the boundary surfaces of the resulting blocks with those of the original blocks. Then, the sliding direction associated with each possible moving block is determined by solving an optimization problem. The normal force acting on each sliding surface is determined, and the resisting force on each rock bridge is calculated and integrated into the total resisting force when calculating the ...

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