急倾斜煤层工作面应力分布与破坏特征数值模拟

根据新铁煤矿49#下右六片急倾斜煤层走向长壁综采工作面煤岩赋存条件以及回采工作面采空区冒落矸石的充填特征,应用FLAC3D软件模拟在采空区中下部矸石自溜充填后工作面采动煤岩应力分布规律及顶底板破坏特征。研究结果表明:急倾斜煤层开采过后,工作面上下端部垂直应力集中系数最大,应力集中现象非常严重且在采空区后方距工作面煤壁15 m附近上下端部垂直应力达到最大值;在采空区后方随着距工作面煤壁距离的增加,剪切应力先减小,然后增加,最后趋于稳定,在采空区后方距工作面煤壁34～38 m区域剪切应力最小;工作面顶板塑性破坏剧烈,塑性破坏形式多样,工作面底板破坏较小,破坏形式简单,顶板上端部破坏高度小,顶板下端部破坏高度大。

Numerical simulation of Working Face Stress Distribution and Failure Characteristics for Steep Seam

According to the coal rock occurrence conditions of longwall fully mechanized working face and caving gangue filling characteristics in 49# right six pieces of steep seam in Xintie Coal Mine,the paper uses FLAC3D software to simulate rock stress distribution laws and roof and floor destruction features after gangue self-slip filling in the lower parts of goaf.The results of the study show that vertical stress concentration coefficient at the ends of working face is biggest after mining steep seam,stress concentration phenomenon is very serious,and the vertical stress in the goaf rear near the coal wall 15 m away from the face is maximum.With the increase of distance from goaf rear to face coal wall,shear stress first decreases,and then increases,and finally becomes stable.The shear stress is minimum when the goaf rear is away from the face coal wall 34 ~ 38 m.Roof plastic damage of working face is violent,the plastic damage ways are various,the face floor is less damage,destroy is simple in form,the damage height of roof upper end is small,the damage height of roof lower end is big.