露天矿含斜交断层顺倾层状边坡稳定性三维数值模拟

3D numerical simulation for the stability of the dip-bedded slope with a heterotropic fault in the open-cast mine

为揭示露天矿含斜交断层顺倾层状边坡的变形破坏规律及其力学成因机制、明确断层对边坡变形与稳定性的影响,以元宝山露天煤矿东帮边坡为工程背景,应用有限差分软件FLAC3D,基于强度折减理论,对含斜交断层顺倾层状边坡稳定性进行了三维数值模拟。结果表明:元宝山露天矿东帮边坡的滑坡模式为以4#弱层为底界面、以断层面与椭球面相交形成的不规则曲面为侧界面的切层-顺层滑动;边坡整体稳定性较好,其滑坡的力学成因机制类型为推动式;多个顺倾弱层对边坡变形具有叠加效应,而斜交断层的切割会一定程度上削弱弱层对边坡变形的控制作用。

The present paper is to devote itself to a 3D numerical simulation for the stability of the dip-bedded slope with a heterotropic fault in the open-cast mines by taking the eastern slope of the Yuanbaoshan open-cast mine as a case study sample.As a common product of the geological process and the artificial excavation,the slope stability in the said open-cast mine has been usually influenced by such unfavorable geological structures,as the fault and the venerable layer,which has in turn made its deformation and damage tendency very complicated,resulting in one of the most controversial problems in such mining fields.To explore the deformation and failure regularity and the mechanical genesis mechanism of the dip bedded slope with heterotropic faults in such open-cast mines and determine the impact of the faults on the slope deformation,we have managed to make a numerical simulation as the engineering background based on the strength reduction theory.For the above said research purpose,we have also studied the stability of such slopes by using a finite difference software named FLAC3 D.A detailed analysis of the three-dimensional contours of the displacement magnitude and the strain increment has made us able to demonstrate the entire internal movement and deformation regularity of the slope rock,thus,determining the potential failure mode,the position and the shape of the sliding surface from the point of view of the spatial angle.Through the comparison and analysis of the evolution and distribution laws of the slope at different sections,it would be possible for us to clarify and determinate the types of the landslide kinetics and the genetic mechanisms so as to reveal the effects of the heterotropic faults and the weak layers on the consequential deformation and damage.The above study results also indicate that the failure mode of the eastern slope in Yuanbaoshan Open-cast Mine has resulted in the cutting-bed slipping along the side surface when it comes cross fault F1 and an ellipsoid with the 4thweak layer at the bottom interface.In such a situation,the entire slope stability and the sliding mechanical genesis mechanism tends to become a strong driving force to produce a combined effect on the multiple weak layers to push the slope deformation.Therefore,the cutting force of the heterotropic fault tends to slacken the control function of the weak layers and in turn promote the slope deformation.