软硬互层型平缓反倾岩质斜坡采动变形破坏机理研究

Study on mining-induced deformation and failure mechanism of soft and hard interbedded gentle counter-inclined rocky slopes

为研究我国西南矿区软硬互层型平缓反倾岩质斜坡采动变形破坏机理,以我国贵州省都匀市某煤洞坡为例,采用数值模拟方法,分析采动诱发软硬互层型平缓反倾岩质斜坡的变形破坏特征,讨论采动对坡体的作用规律,研究单工况采动和留煤柱下重复采动对坡体的变形破坏机理。研究结果表明:靠近坡表工作面开采和留煤柱下重复采动对坡体的稳定性影响较大;采动裂隙首先集中于采空区两侧并向上发展,软硬夹层间产生离层裂隙的可能性一般较大;留煤柱可防止坡体沉陷破碎,但也可能加剧坡体稳定性下降。研究结果可为软硬互层型平缓反倾岩质斜坡地下开采时,有效预防诱发山体失稳等地质灾害提供理论参考。

In order to study the mining-induced deformation and failure mechanism of soft and hard interbedded gentle counter-inclined rocky slopes in southwestern mining area of China,taking Duyun coal cave slope of Guizhou province as an example,the numerical simulation was used to analyze the deformation and failure characteristics of soft and hard interbedded gentle counter-inclined rocky slopes induced by mining.The action law of mining on the slopes was discussed,and the deformation and failure mechanism of the slopes by single-condition mining and repetitive mining under the retained coal pillar was studied.The results show that the mining close to the slope surface working face and the repetitive mining under the retained coal pillar have the greater influence on the stability of slope body.The mining-induced fissures are first concentrated on both sides of goaf and develop upward,and the separation fissures between soft and hard interlayers are generally likely to occur.The retained coal pillar can prevent the slope subsidence and fragmentation,but it may also aggravate the decline of slope stability.The research results can provide a theoretical reference for the geological disasters of mountain instability induced by underground mining of soft and hard interbedded gentle counter-inclined rocky slopes.