Domino instability effect of surrounding rock-coal pillars in a room-and-pillar gob  

作　　者：Li Chong Xu Jinhai Wang Zhongliang Qin Shuai 

机构地区：[1]School of Mines,Key Laboratory of Deep Coal Resource Mining of Ministry of Education,China University of Mining&Technology [2]State Key Laboratory of Geomechanics and Deep Underground Engineering,China University of Mining&Technology [3]State Key Laboratory of Coal Resources and Mine Safety,China University of Mining&Technology

出　　处：《International Journal of Mining Science and Technology》2013年第6期913-918,共6页矿业科学技术学报（英文版）

基　　金：supported by the National Natural Science Foundation for Youth(No.51304200);the China Postdoctoral Science Foundation Project(No.2013M540477);the Superior Subject Construction Project of Universities in Jiangsu Province,the Independent Research Project of State Key Laboratory of Coal Resources and Mine Safety(No.SKLCRSM11X02);the National Natural Science Foundation of China(No.51074163)

摘　　要：To discuss the domino instability effect and large area roof falling and roof accidents of surrounding rockcoal pillars in a room-and-pillar gob,the equilibrium equation for a roof-coal pillar-floor system with the influence of mining floor was developed based on the engineering conditions of the surrounding rock in a room-and-pillar gob in the 3^(-2)coal seam of Tanggonggou mine.The conditions of system instability and the relationship between system stability and system stiffness were analyzed from an energetic point of view.Numerical simulation using the discrete element software UDEC was also carried out to simulate conditions causing the domino effect on surrounding rock-coal pillars in a 3^(-2)room-and-pillar gob.The results show that:if we want the system to destabilize,the collective energy in roof-and-floor must be larger than that in the coal pillar.When the stiffness of the coal pillars and the roof-and-floor are both greater than zero,the system is stable.When the stiffness of the coal pillars is negative but the summed stiffness of the coal pillars and roof-and-floor is larger than or equal to zero,the system is statically destroyed.When the sum of the coal pillars and the roof-floor stiffness is negative,the system suffers from severe damages.For equal advance distances of the coal mining face,the wider coal pillars can reduce the probability of domino type instability.Conversely,the smaller width pillars can increase the instability probability.Domino type instability of surrounding rock-coal pillars is predicted to be unlikely when the width of coal pillars is not less than 8 m.To discuss the domino instability effect and large area roof falling and roof accidents of surrounding rock-coal pillars in a room-and-pillar gob, the equilibrium equation for a roof-coal pillar-floor system with the influence of mining floor was developed based on the engineering conditions of the surrounding rock in a room-and-pillar gob in the 3-2 coal seam of Tanggonggou mine. The conditions of system instability and the relationship between system stability and system stiffness were analyzed from an energetic point of view. Numerical simulation using the discrete element software UDEC was also carried out to simulate conditions causing the domino effect on surrounding rock-coal pillars in a 3-2 room-and-pillar gob. The results show that:if we want the system to destabilize, the collective energy in roof-and-floor must be larger than that in the coal pillar. When the stiffness of the coal pillars and the roof-and-floor are both greater than zero, the system is stable. When the stiffness of the coal pillars is negative but the summed stiffness of the coal pillars and roof-and-floor is larger than or equal to zero, the system is statically destroyed. When the sum of the coal pillars and the roof-floor stiffness is negative, the system suffers from severe damages. For equal advance distances of the coal mining face, the wider coal pillars can reduce the probability of domino type instability. Conversely, the smaller width pillars can increase the instability probability. Domino type instability of surrounding rock-coal pillars is predicted to be unli-kely when the width of coal pillars is not less than 8 m.

关 键 词：Domino effect Surrounding rock Room-and-pillar Gob 

分 类 号：TD32[矿业工程—矿井建设]