(1. College of Resources,Materials and Environment,Guangxi University,Nanning,Guangxi 530004,China;2. College of Civil Engineering,Guangxi University,Nanning,Guangxi 530004,China)
Abstract:As a new index to evaluate the integrity of rock mass,blockiness can reflect the degree of rock fragmentation from a three-dimensional perspective. In order to accurately grasp the sensitivity of the influence parameters of the blockiness index,a series of three-dimensional fracture network models under the influence of three main influence parameters,namely fracture spacing,fracture persistence and fracture occurrence,are constructed by using the joints and interfaces network inverse modeling technology,and blockiness value of each model is calculated;the influence parameters and blockiness index are calculated and analyzed by using the grey correlation analysis method. The results show that the index of blockiness has negative correlation with fracture spacing,positive correlation with fracture persistence,and no obvious relationship with fracture occurrence;the grey correlation degree of fracture spacing,fracture persistence and fracture occurrence with the index of blockiness is 0.779 9,0.622 5 and 0.34,respectively,and the influence of fracture spacing on the index of blockiness is the largest,followed by fracture persistence,the influence degree of fracture occurrence is the least. The research results lay a theoretical foundation for the complete construction of the evaluation method system of the degree of fragmentation of fractured rock mass.