上游式筑坝法尾矿坝的安全系数随堆筑坝高变化分析

Study on variation of safety factor with the dam height for the tailing dam by upstream embankment method

对于投资较少的上游式尾矿筑坝法而言,在实际的堆积施工过程中,由于很难严格按照设计的坡比进行每一级子坝的堆筑,导致矿方无法及时、真正掌握当前尾矿坝的受力性能和稳定状态。因此,针对某典型尾矿坝剖面,采用迈达斯商业软件试用版对尾矿坝的堆积过程进行了模拟分析,利用强度折减有限元方法对施工当前状态的尾矿坝进行了边坡稳定分析,得到了当前状态尾矿坝的塑性剪应变云图和相对应的抗滑稳定安全系数。比较了尾矿坝安全系数随着子坝堆筑的变化情况,结果发现:随着堆积子坝的进行,尾矿坝的整体抗滑稳定系数逐渐减小,此外在初期坝和一级子坝的下游坡脚处容易出现相对较大的变形。此研究结果为矿部管理部门及时了解尾矿坝的稳定程度和实际生产提供了技术支持。

The upstream embankment method is widely used due to its smaller investment in the construction of tailing dams.However,the designed slope inclination is not strictly observed in the real construction of embankment,which yields the difficulty of administrator to be timely and really familiar with the stability state and mechanical performance of the current tailing dam.One typical tailing dam cross section was employed to perform the finite element analysis by using the MIDAS-trial version software and Strength Reduction Method technique.The factors of safety and plastic shear strain contours of the current tailing dam were obtained from the finite element analysis results of the MIDAS trial version.In order to find the variation of safety factor with the increment of embankment height,the factors of safety were compared against each increment of embankment.The results showed that the safety factor became gradually lower with the increment of embankment and larger deformation was found out in the toes of original tailing dam and first-stage tailing dam.The results can provide the administrator with the timely factors of safety of the current tailing dam and also can serve the real construction of increment of embankment.