沿空留巷充填体三维空间约束机理分析与应用

Analysis and application of three dimensional space constraint mechanism of filling body in gob side entry retaining

通过建立沿空留巷巷旁充填体三维结构力学模型,得到了对拉锚杆等外部约束对充填体的约束机理。研究表明:对拉锚杆等外部支护构件对巷旁充填体实施空间约束,可使其自由面转化为受力约束面,从而提高这一结构的整体强度和承载能力。通过FLAC^(3D)数值分析,可知采用充填体三维空间约束结构可提高充填体表面和核心区应力值和范围,其纵向承载载荷比无约束结构提高20%以上,从而可减小充填体横向变形和改善留巷巷道的维护效果。

Aiming at the problem of large deformation of gob side entry retaining body filled with high water content materials,a three-dimensional space constraint structural mechanical model of gob side entry retaining body was established,and the three-dimensional space constraint mechanism of tension bolt,ladder beam and steel mesh on the filling body was obtained.The results show that the free surface of the filling body can be transformed into the stress constrained surface by applying the space constrained prestressed structure to the filling body through the tension bolt,ladder beam and steel mesh supporting components,so as to improve the overall strength and bearing capacity of the filling body.FLAC^(3D) numerical simulation is used to compare and analyze the stress distribution characteristics of filling body under different constraint parameters.The three-dimensional space constraint structure of filling body can improve the stress value and range of filling body surface and core area,and its longitudinal load can be increased by more than 20%,compared with the unconstrained structure,so as to reduce the transverse deformation of filling body and improve the maintenance effect of retained roadway.The research results have been successfully applied in the field.