露天矿土-岩复合边坡形态优化设计

On the optimum layout of the soil and rock composite slope in an open pit mine

合理设计采场及排土场边坡角是优化露天开采境界、保证露天矿安全生产、提高露天矿经济效益的重要前提。针对土-岩复合边坡这一类复杂特殊的边坡,以宝日希勒露天煤矿二采区西帮边坡为工程背景,应用刚体极限平衡软件定量分析了二采区西帮采场边坡及内排土场边坡的潜在滑坡模式;优化设计了二采区西帮1-2煤底板以上内排边坡形态及1-2煤至3煤之间采场边坡形态;确定了二采区西帮采场与排土场之间的安全距离。采用有限差分数值模拟软件FLAC^（3D）,基于强度折减理论,对土-岩复合边坡稳定性进行了数值模拟,揭示了二采区西帮土-岩复合边坡的变形破坏机理及其稳定性。结果表明：宝日希勒露天煤矿二采区西帮土-岩复合边坡滑移模式及稳定性主要受采场与排土场之间的安全距离和3煤顶底板弱层控制;边坡形态优化后1-2煤底板以上内排边坡角为12°,1-2煤至3煤之间采场边坡角为22°,采场与排土场之间的安全距离为120 m,土-岩复合边坡整体边坡角为13°。

The paper is aimed at finding the optimum design version for the type of the Baorixile opencast coal mine along the soil and rock composite slope,with the western slope of the second working field as the engineering background through quantitative analysis. For this purpose,we have,first of all,identified and determined the potential landslide stope situation and its slope shape between No. 1-2 and No. 3 coal mine＇s inner dump slopes,by applying the body limit equilibrium software to the western No.2 working field. In so-doing,we have taken the primary premise to optimize the open pit mining area to ensure the safety production. The analysis we have done is based on the theory of strength reduction,the stability of the soil and the rock composite slope through a finite difference numerical simulation software with FLAC3 D,which helps us to make sure the stability and the mechanism of deformation and destruction of the soil and rock comprising slope in the said area. The results of our study indicate that the western slope sliding mode and the stability of the soil and rock comprising slope of the 2-nd field in the mine are mainly influenced and impacted by the safety distance between the stope and the dumping site as well as the roof and floor of the weak layer of NO. 3 mine,whereas the steady slope angle above NO. 1-2 coal floor is equal to 12° and that between No. 1-2 coal and No. 3 stands at 22°,with the safety distance between the stope and the dumping site being 120 m and the angle of the soil and rock composite slope—13° as a result of the slope shape optimization.