Abstract:In underground mining engineering, the degree of crack development in rock mass has a significant impact on the mechanical properties, and it is an important indicator that affects the safety and stability. To the uncertainty and randomness of rock mass fracture distribution, it has posed challenges to scientific research and safe construction of such rock mechanics problems. Based on the Monte Carlo method of random theory and the Baecher disk assumption of rock fracture surface, the mathematical probability density function has been derived in the rock fracture structure parameters. The distribution relationship has been proposed between trace length (L) and diameter (D) from a statistical perspective, and an improved prior model of fracture structure geometric parameters was established. By the help of Matlab-Dimine joint modeling and computer program implementation technology, a three-dimensional random fracture network generation program flow was designed. Taking the actual situation of an underground tunnel project in a certain mine, as a case study, an on-site engineering geological survey of the mine was carried out, and the fracture occurrence parameters of the underground tunnel project were obtained. A true three-dimensional random fracture network digital spatial structure model of the rock mass has been constructed using self programming methods, realizing the digital reconstruction of the rock mass fracture network model in underground mine engineering. The? results indicate that: (1) Based on statistical parameters of rock mechanics, a prior model of trace length and fracture diameter has been proposed, and the distribution relationship between observed trace length (L) and fracture diameter (D) has been improved, achieving digital reconstruction of the underground rock fracture structure model in mines; (2) Taking the underground tunnel project of a certain mine as an example, the geological survey parameters of the mine rock mass engineering were systematically analyzed, and digital data of rock mass fractures were obtained. A digital ore body model with a highly simulated three-dimensional random fracture network was constructed, providing a new method for solving the three-dimensional digitization of fractured rock mass.Keywords:Random method, Three-dimensional random fracture network, Joint modeling, Fracture digitizing