Abstract
In the analysis of multi-working face stopes using block theory, the established rock mass model is a complex concave body, and the classic plane cutting algorithm for convex polyhedra cannot be used. To address the challenge, a cavity polyhedron model is constructed through the combination of convex sub-regions, and a detailed methodology for the construction of concave models is provided. In the combinatorial model, the classical cutting algorithm is unrestricted. Subsequently, block identification is achieved through the contraction of structural planes and the merging of sub-regions, which avoids cutting concave polyhedra and takes into account the actual dimensions of structural planes, overcoming the assumption of infinite structural planes in traditional methods. Combining with a shallow underground stope, all independent blocks in the study area are identified. The basic information of the key blocks around the surrounding rock is also provided. The calculation results show that this method can precisely identify all blocks formed by finite structural planes within concave models, regardless of their shapes and quantities. It proves the effectiveness and accuracy of this method applied to multi-working face stopes, and provides technical support for ensuring the safe production of underground stopes.