生态修复尾矿坝的边坡稳定性评价

当前的尾矿坝稳定性分析中,不考虑植物作用的影响,难以满足尾矿库综合治理的客观要求。以歪头山铁矿尾矿库为例,采集现场生态修复区的植物与根际土壤样品;制作灌木侧须根-土复合土,测定复合土的渗透系数和物理力学性质指标;测量植物生长参数,进行主根条拉伸实验;基于极限平衡法,计算在正常运行、洪水运行、特殊运行工况下,生态修复尾矿坝的浸润线及安全系数。结果表明:无植物体、植物侧须根加筋、植物侧须根加筋+主根锚固+自重等3种状态下,生态修复后尾矿坝的安全系数提高0.025~0.030,说明植物修复有利于坝体稳定,但影响仅限于表层,对整体稳定性影响有限;特殊工况比洪水工况的坝体安全系数略有降低,且随地震时程呈先减小后增加再减小的波动趋势;稳定性评价结果表明,该尾矿坝在3种运行工况下是安全稳定的。

Evaluation on Slope Stability of Ecological Remediation Tailings Dam

In the current stability analysis of tailings dam， the influence of plants has not considered， resulting in difficulty to meet the objective requirements of comprehensive management of tailings pond. Taking the tailings pond in Waitoushan iron mine as an example， the plants and rhizosphere soil were sampled in the ecological remediation area. The shrub lateral fibrous root-soil composite soil mass was prepared， and its seepage coefficient and physical mechanical indexes were measured. The parameters of plant growth were measured to carry out the experiment of taproot stretch. Based on the limited equilibrium method， the seepage line and safety factors of ecological remediation tailings dam under different conditions such as normal， flood and special were calculated. The results show that the safety factors of tailings dam can be increased by 0.025~0.030 under three ecological restoration conditions， namely， no plants， plant side fibrous root reinforcement， plant side fibrous root reinforcement + taproot anchorage + plant weight. The safety factor of the tailings dam under special conditions is slightly lower than that under flood conditions， and its fluctuation trend decreases first， then increases and then decreases with the time history of earthquake. The stability evaluation results show that the tailings dam is safe and stable under three operating conditions.