尾矿库边坡时变分析模型及其应用

A time-varying analytic model of tailings slope and its application

尾矿库边坡稳定性多以单一安全系数为评价指标,难以反映外界条件变化的过程中尾矿库边坡稳定性演化的全过程特征。针对这一问题,提出尾矿库稳定性的时变分析方法,以安全系数时程曲线分析尾矿库边坡稳定性。以尾矿库工程实例为研究对象,建立时变分析模型进行数值模拟。研究在不同降雨入渗、库水位变动以及二者耦合条件下边坡安全系数随时间变化的规律。研究结果表明,不同强度的均匀降雨影响下,6 h以后安全系数下降速率大致相当,6 h以内雨强越大,安全系数下降越快。降雨雨型将影响安全系数变化轨迹,研究较为广泛的均匀雨型并不是最危险雨型。边坡安全系数变化滞后于库水位变动,滞后效应随水位上涨速度的减慢、下降速度的加快和涨幅的减少而减弱。耦合条件下尾矿库边坡安全系数减小将加剧。研究成果对尾矿库设计和运营具有重要意义。

Single safety factors are used for most stability assessments of tailings slopes which can not reflect the whole evolutions of stabilities of tailings slopes subjected to variations of external condition. A method of time-varying analysis of tailings slopes was proposed to solve this problem and the time-history of safety factor was used to evaluate the stabilities of tailings slopes. A time-varying model was established to analyze a tailings pond. Conditions of rainfall infiltration, water level fluctuation and the associative action of both of them were simulated by numerical method to study the variation of safety factor with time. The results show that after 6 hours the rates of decrease in safety factor under different rainfall intensities are similar. But within 6 hours the greater the rainfall intensity is, the faster it decreases safety factor. The rain types will affect the trajectory of the variation of the safety factor;and the constant rain which is widely studied is not the most critical rain type. The variation of the safety factor lags behind the water level fluctuation. And the hysteretic effect is weakened by the declination of rising rate, the increasing of descending rate and the decreasing of the varying range of the water level. It is of important significance for the designation and operation of tailings ponds.