巷道锚喷补偿收缩钢纤维砼支护结构数值分析

巷道支护结构稳定是煤矿安全生产的前提,结合巷道混凝土破坏特征和混凝土材料复合增强原理,提出喷射补偿收缩钢纤维混凝土作为支护材料。以朱集矿-965水平轨道大巷为工况,采用ANSYS数值软件对巷道锚杆-喷射补偿收缩钢纤维混凝土支护结构的稳定性进行数值分析。考虑围岩作用下锚杆与喷射补偿收缩钢纤维混凝土支护体系建立三维有限元模型。采用弹塑性D-P本构模型进行计算,得出围岩-支护结构体系下围岩的应力场、位移场、塑性区以及支护内力的分布规律。通过荷载步设置探讨巷道开挖对围岩稳定性的影响,以及支护结构的受力特征,找出巷道支护结构的"危险点"和围岩的应力集中区。提出喷射补偿收缩钢纤维混凝土的支护措施。通过工业性试验验证了该支护结构体系能够有效地改善和提高支护结构的稳定性。

Numerical analysis of Bolt and shrinkage-compensating steel fiber reinforced shotcrete Supporting Structure For Tunnel

Stability of roadway support structure for Tunnel is the precondition of coal mine safety production, combining with the characteristics of roadway concrete and composite reinforced concrete material principle, proposed compensating shrinkage of steel fiber reinforced shotcrete as supporting material.In this paper, Zhuji Mine-965 level track alley is selected as the example. using numerical software ANSYS to analyze the stability of the roadway support structure. Considering three-dimensional finite element analyzing for rock bolt and adopting elastic-plastic D-P constitutive model to calculate, shrinkage-compensating steel fiber reinforced shotcrete under the effect of surrounding rock, distribution regularities of stress field, displacement field, plastic zone and internal supporting force of surrounding rock under surrounding rock supporting structure system have come to a conclusion. The influence on the stability of surrounding rock by roadway excavation as well as mechanics characteristic of supporting structure are explored by setting up load steps. The "risk point" of roadway supporting and surrounding rock stress concentration areas are found out. Meanwhile, supporting measures proved by industrial test for shrinkage-compensating steel fiber reinforced shotcrete which could improve the stability of the supporting structure are proposed.