在分析目前大断面煤巷锚杆支护存在问题的基础上,论述了对锚杆支护机理的新认识,开发了适合于大断面煤巷支护的高强度锚杆,并采用FLAC3D有限差分程序对不同锚杆支护参数巷道围岩应力场分布特征与规律进行了模拟分析。结果表明:预紧力是锚杆支护系统的决定性参数,增加锚杆预紧力能有效增大巷道围岩压应力场应力值及扩散范围;锚杆长度的选择应充分考虑锚杆预应力、巷道围岩破碎程度与可锚性;对于相同锚杆材料,直径越大强度越高,预应力扩散范围越大;锚杆垂直于岩面布置时,巷道围岩形成的压应力区分布更加均匀,锚杆预应力叠加效果更好。井下试验表明,高强度锚杆支护技术为大断面煤巷提供了有效的支护手段,巷道掘进期间两帮移近量25.0 mm,顶底板移近量16.6 mm,能有效控制围岩的强烈变形。

Based on the analysis on the problems existed in the bolt support of the present large cross section seam gateway, a new knowledge of the bolt support mechanism was stated and a high strength bolt suitable for the mine large cross section seam gateway was developed.The FLAC3D finite differential program was appli ed to the simulation analysis on the stress field distribution features and law of the surrounding rock along the seam gateway with different bolt support parameters.The results showed that the pre-tensile strength was the decisive parameter of the bolt support system and the increased pre-tensile strength of the bolt could effectively im prove the stress value and expansion scope of the stress field in the surrounding rock of the mine gateway.The selection of the bolt length should fully consider the pre- stress of the bolt, the broken degree and boltability of the gateway surrounding rock.As for the same material of the bolt, the larger diameter of the bolt, the higher stren gth of the bolt would be and the larger of the pre-stress expansion scope would be.When the bolt was vertical to the rock stratum surface, the distribution of the pressur e stress zone formed by the gateway surrounding rock would be more even and the superposition effect of the bolt pre-stress would be better. The underground mine tes ts showed that the high strength bolt support technology could provide the effective support means to the large cross section seam gateway.During the gateway driving period, the convergence between the two side walls was 25.0 mm, the convergence between the roof and floor was 16.6 mm and the serious deformation of the surroun ding rock could be effectively controlled.

“十一五”国家科技支撑计划资助项目(2008BAB36B07)；