Instability energy mechanism of super-large section crossing chambers in deep coal mines  

作　　者：Deyuan Fan Xuesheng Liu Yunliang Tan Xuebin Li Purev Lkhamsuren 

机构地区：[1]College of Energy and Mining Engineering,Shandong University of Science and Technology,Qingdao 266590,China [2]State Key Laboratory of Mining Disaster Prevention and Control,Shandong University of Science and Technology,Qingdao 266590,China [3]School of Geology and Mining,Mongolian University of Science and Technology,Ulaanbaatar 120646,Mongolia

出　　处：《International Journal of Mining Science and Technology》2022年第5期1075-1086,共12页矿业科学技术学报（英文版）

基　　金：The authors gratefully acknowledge the financial support from the National Natural Science Foundation of China(Nos.52174122,52074168 and 51874190);Climbing Project of Taishan Scholar in Shandong Province(No.tspd20210313).

摘　　要：The stress concentration and failure at chamber intersections in coal mine are intense,especially in deepburied,super-large section conditions.In this paper,the plastic radius of super-large section chamber under unequal pressure was corrected on the basis of the size effect.Then,stress and failure evolution of intersections under different crossing angles and equivalent angular bisectors were revealed.Furthermore,2 trajectory curves of failure and stress were analytically expressed,which divided the intersection into 5 influencing zones in the light of stress superposition degree.After determining instability trigger point and instability path,instability energy criterion of intersection can be obtained as K>1,which means that the external energy is greater than the sum of energy consumed by surrounding rock instability and supporting structure failure.Taking coal-gangue separation system of Longgu Coal Mine as example,it was found that there was instability risk under original parameters.For long-term stability,an optimization design method was proposed by considering safety factor,and optimal support scheme was obtained.Field monitoring showed intersections deformations were relatively small with the maximum of 125 mm,which verified the rationality of theoretical analysis.This study provides guidance for the stability control of the intersections under the same or similar conditions.

关 键 词：Super-large section INTERSECTION Instability energy mechanism Optimization design Field monitoring 

分 类 号：TD354[矿业工程—矿井建设]