不同降雨条件下露天矿含泥岩弱层边坡稳定性分析

Stability analysis of slope with mudstone weak layer in open-pit mine under different rainfall conditions

为了研究不同降雨条件下露天矿含泥岩弱层边坡的稳定性变化规律,以新疆维吾尔自治区某露天煤矿西端帮边坡为工程背景,采用滤纸法获得了泥岩土-水特征曲线,借助COMSOL软件对不同降雨条件下的西端帮进行了渗流与应力耦合计算。结果表明:不同降雨条件下边坡安全系数在降雨期间均快速下降,降雨结束后均缓慢回升,但在较长一段时间内仍低于边坡初始安全系数;短时强降雨比长时弱降雨对边坡稳定性的影响更剧烈,但在降雨结束后安全系数回升得更快;塑性应变首先产生于泥岩弱层中并沿泥岩弱层逐渐向边坡深部发展,最终形成贯通边坡的塑性区。

In order to study the stability change law of slopes with mudstone weak layer in open-pit mine under different rainfall conditions,the west end slope of an open-pit coal mine in Xinjiang Autonomous Region was selected as the study area.The soil-water characteristic curve of the mudstone was obtained using the filter paper method.The coupled seepage and stress calculation of the west end slope under different rainfall conditions was carried out by COMSOL software.The results show that the safety factor of the slope experiences a rapid decline during the rainfall period and gradually recovers after the rainfall ends,but remains below the initial safety factor for an extended duration.Short-time intense rainfall has a more significant impact on slope stability than long-time weak rainfall,but the safety factor recovers faster after the rainfall ends.The plastic strain firstly arises in the mudstone weak layer and spreads gradually along the mudstone weak layer to the deeper parts of the slope,ultimately forming a plastic zone throughout the slope.