考虑模袋体非连续性的某模袋法尾矿坝稳定性分析

Stability Analysis of a Tailings Dam Built with Geofabriform Considering Discontinuity of the Geofabriform

模袋法尾矿坝是一种新型尾矿坝堆坝技术,模袋体之间及模袋体与尾矿库砂的相互作用是典型的非连续问题。考虑了模袋体的大位移、大变形及模袋体与尾矿库砂之间的滑移脱离特性,以我国某模袋法尾矿坝为例,基于非连续-连续耦合方法分析了模袋法尾矿坝的稳定性和失稳破坏过程,研究了模袋体层间接触特性对坝体稳定性的影响规律。结果表明:模袋法尾矿坝相较传统的上游法尾矿坝安全系数提高了20.1%,模袋法堆坝技术有利于增强坝体稳定。尾矿坝失稳瞬间坝坡顶点、中点和坡脚点处位移发生突变,尾矿坝失稳后,坝坡明显坍落,尾矿砂在模袋子坝坡脚处堆积。对于坝坡坡度较缓的模袋法尾矿坝,提高模袋体层间抗剪强度对尾矿坝稳定性的提升效果有限。

Tailings dam built with geofabriform is a new type of dam stacking technology.The interaction between the geofabriform bodies and the interaction between geofabriform dam and tailings sand are typical discontinuous problems.The large displacement and deformation of geofabriform body and the slip-off characteristics between geofabriform and tailings sand were considered in this paper.Taking a tailings dam built with geofabriform in China as an example,the stability and the instability failure process of the geofabriform-based tailings dam were analyzed based on a discontinuous-continuous coupling method.The impact of interlayer contact characteristics of geofabriforms on the dam stability was studied.The results indicate that the safety factor of the geofabriform-based tailings dam increased by 20.1% compared to the traditional upstream method tailings dam,and the geofabriform dam construction technology is beneficial for enhancing the stability of the dam.At the moment of dam instability,there was a sudden change in the displacement at the top,midpoint,and toe of the dam slope.After the dam became unstable,the dam slope collapsed noticeably,and the tailings sand accumulated at the toe of the geofabriform sub-dam.For geofabriform-based tailings dams with gentler slope gradients,increasing the shear strength between layers of the geofabriform had a limited effect on enhancing the stability of the tailings dam.