关键词: 深部巷道　, 围岩分级　, 支护参数优化　, 数值模拟　, 支护效果

Abstract: The surrounding rock of the Liutangfang Iron Mine in Anhui Province exhibits a gently inclined layered struc ture,making it inherently prone to rock delamination and collapse during extraction;as mining depth increases,the roadway roof support system and its parameters urgently require optimization and upgrading.To address this,joint and fracture parameters of the ore rock were first statistically analyzed to classify the quality of the deep surrounding rock,and then a subitem quantitative weighted scoring method was adopted to rate the roof support grade based on three primary factors:surrounding rock quality classification,crosssectional dimensions,and service life and function.Subsequently,numerical simulations of roadway stability were conducted under various support methods and parameters,which revealed the influence mechanisms of different support techniques on the extent of the loosening zone,stress concentration zones,and plastic zones,while also quantitatively assessing the effects of concrete,rock bolts,and boltmesh combined support on maximum roadway settlement and roof control ratio.The results show that,within the constraints of support cost,the order of influence on support effectiveness is concrete thickness> bolt spacing>mesh reinforcement>bolt length;When the support effectiveness falls below 30%,the system is undersupported and increased expenditure can significantly improve performance,whereas when it exceeds 45%,the system becomes oversup ported and further cost increases yield only marginal gains.Finally,based on a comparative optimization of support effectiveness and cost,a set of graded support schemes and parameter optimization proposals is put forward,and the findings are expected to provide a useful reference for roof classification and support design in similar underground mining projects.