浅埋下向单一进路巷道胶结充填顶板稳定性分析

Stability analysis of cemented filling roof under the condition of shallow downward single route type of roadway

基于急倾斜破碎围岩薄矿体中下向进路分层无分段巷道充填法,对浅埋单一进路巷道上覆充填顶板建立了"嵌固梁"力学模型,解出了单一进路巷道上覆充填顶板均布荷载理论值。将半逆解法引入上覆充填顶板力学分析中,推导出均布荷载下"嵌固梁"应力分量与挠曲线方程。结合某金矿现有开采技术条件,分析得出锚杆(索)提供给充填顶板与上下盘围岩的抗剪力对上覆充填顶板所受均布荷载值影响较小,而锚杆提供给充填顶板与矿体两侧矿柱的抗剪力对其所受均布荷载值影响较大,单层进路巷道上覆充填顶板弯曲变形量呈抛物线形分布,且最下一分层上覆充填体最大挠度值为0.363 m。由于进路巷道采用差别充填,当单层承载层厚度不小于2.35 m时才能确保上覆充填顶板始终处于稳定状态。

Based on the downward drift slicing without sublevel backfilling method under the condition of steeply inclined thin ore body with crushed surrounded rock, the ＂restrained beam＂ mechanical model is established for the overlying filling roof in the single route type of roadway under the condition of shallow buried strata, and the theoretical even load value of overlying filling roof in the single route type of roadway is calculated accordingly. Semi-inverse method is introduced into the overlying filling roof mechanical analysis to deduct the stress component and deflection equations of ＂restrained beam＂ under the condition of the even load. According to the mining technical conditions of a certain gold mine, the paper has obtained that the shearing resistance between filling roof and wall rock of upper and lower sides which is supplied by anchors and cables have a lower impact on even load value sustained by overlying filling roof, while shearing resistance between filling roof and both sides of pillar which is supplied by anchors have a greater impact on its even load value. The bending deformation of single walled filling roof is distributed in accordance with parabola style, and the maximum deflection value of the last layer of filling roof is 0.363 m. Because of adopting distinct filling method in terms of drift roadway, the stability of the overlying filling roof will be ensured consistently only when the bearing layer thickness is equal or larger than 2.35 m.