混合边界护顶层力学模型及应用  

Mechanical model and application of mixed boundary protection roof

作　　者：李启月[1] 黄海仙 魏新傲 李海谦 廖晓目 LI Qiyue;HUANG Haixian;WEI Xin’ao;LI Haiqian;LIAO Xiaomu(School of Resources and Safety Engineering,Central South University,Changsha 410083,China)

机构地区：[1]中南大学资源与安全工程学院,长沙410083

出　　处：《中国有色金属学报》2024年第3期984-996,共13页The Chinese Journal of Nonferrous Metals

摘　　要：对于直接顶板稳固性较差的矿山,通常需留设护顶层以防止直接顶板的垮塌。为了保证矿山的安全开采,确定合理的护顶层厚度至关重要。针对房柱法开采的采空区顶板进行结构力学解析,将护顶层视作四边中部自由其余部分固支的薄板,即混合边界薄板;利用功的互等法推导出混合边界薄板的挠曲面方程,构建混合边界护顶层力学模型,在此基础上得到护顶层安全厚度的计算公式。将混合边界薄板与四边固支薄板的变形情况进行对比时发现,混合边界薄板的挠度整体大于四边固支薄板挠度,混合边界自由段长度与最大挠度值呈正相关。将理论分析和数值模拟结合应用在某铝土矿No.9采场上,确定了护顶层安全厚度为1 m,验证了力学模型的准确性。For mines with poor stability of direct roof,it is usually necessary to reserve protective roof to prevent collapse of direct roof.In order to ensure safe mining,it is very important to determine reasonable thickness of protective roof.According to the structural mechanics analysis of goaf roof of room pillar mining,protective roof was regarded as thin plate fixed by the free rest of four sides in the middle,that is,mixed boundary thin plate.Using reciprocal theorem,deflection surface equation of thin plate with mixed boundary was derived,and the mechanical model of protective roof with mixed boundary was constructed.On this basis,calculation formula of safe thickness of top protective roof was obtained.The results show that,by comparing deformation of thin plate with mixed boundary and thin plate with four fixed edges,the deflection of the mixed-boundary thin plate is larger than that of the four-sided fixed thin plate,and the length of the free section of the mixed boundary is positively correlated with the maximum deflection.The results of theoretical analysis and numerical simulation have been applied to No.9 stope of a bauxite mine,and the safety thickness of protective roof is determined to be 1 m,which verifies the accuracy of the mechanical model.

关 键 词：力学模型 弹性薄板理论 功的互等法 护顶层 混合边界薄板 

分 类 号：TD853[矿业工程—金属矿开采]