新集二矿1煤组采场底板应力场分布及破坏特征研究

Study on Stress Field Distribution and Failure Characteristics of Goaf 1 Coal Seam Floor Plate in Xinji No.2 Mine

为了研究1煤组采场底板的应力场分布及变形破坏特征,基于新集二矿220108采煤工作面的实际工况,运用有限差分数值模拟软件FLAC构建二维数值模型,得到煤组采场底板应力场、位移及塑性破坏带的分布云图。结果表明:工作面开挖以后,在上覆岩层和下部承压水耦合作用下,底板形成一定范围的拉应力区,采空区两端产生剪应力集中区,底板发生底鼓变形,随着工作面的推进,拉应力区范围增大,剪应力集中区也不断向底板延伸,采空区底板垂直位移最大可达844.5 mm,可能会导致底板隔水层发生破坏;围岩的塑性破坏带最先出现在采空区两侧,随着工作面的推进,塑性破坏带范围逐渐增大并向底板扩展延伸,当工作面推进到100 m时,底板隔水层两端的塑性区相互融合,成为导水通道。

In order to study the stress field distribution and deformation and failure characteristics of the floor plate of the coal group stope,based on the actual working conditions of the mining face 210108 of Xinji No.2 coal mine,a two-dimensional numerical model was established by using FLAC,and the distribution nephogram of the stress field,displacement and plastic failure area of the floor plate of the coal group stope was obtained.The results show that after the excavation of the working face,under the coupling action of overlying strata and confined water below,the floor plate forms a certain range of tension stress zone,shear stress concentration zone occurs at both ends of the goaf and floor plate heave deformation occurs.With the advancing of the working face,the range of tension stress zone increases,and the shear stress concentration zone extends continuously to the floor plate.The maximum vertical displacement of the floor plate in the goaf can reach 844.5 mm.The plastic failure zone of surrounding rock first appears on both sides of the goaf.With the advancing of the working face,the plastic failure zone gradually increases and extends to the floor plate.When the working face advances to 100 m,the plastic zone at both ends of the floor plate water barrier fuses and becomes a water diversion channel.