武阳高速某尾矿库坝体渗流稳定性及溃坝演进过程分析

Analysis of Seepage Stability and Dam Break Evolution Treatment of Tailings Pond Dam on Wuyang Expressway

尾矿库作为一个具有高势能的人造泥石流危险源,一旦溃坝会造成严重的人员伤亡和财产损失。为研究武阳高速某尾矿库对一大桥安全的影响,采用现场调查、采样和室内试验等手段,通过建立该尾矿库地质概化模型和坝体渗流稳定性分析数值模型,对尾矿库坝体渗流稳定性及溃坝演进过程进行了分析。结果表明:(1)在非渗流状态下,现状坝体处于饱水工况时,新筑子坝安全系数为0.987,闭库坝体处于饱水工况时,新筑子坝安全系数为0.942;在渗流状态下,现状和闭库坝体处于洪水运行工况时,均会发生溃坝,新筑子坝最小安全系数为0.665,与现场坝体的变形迹象相符;(2)在考虑地震运行工况时,由于地震荷载作用,坝体的稳定性明显降低,潜在的最危险滑面均位于新筑子坝当中,闭库坝体在饱水和地震运行工况同时作用下,新筑子坝会发生溃坝,其最小安全系数为0.759;(3)尾矿库溃流有可能会对高速公路及桥梁产生巨大破坏,破坏方式主要有冲击、冲刷、堆积、磨蚀;砂流演进过程中,坝址最大砂流量为1814 m^(3)/s,砂泥流断面平均流速为0.99 m/s,水库泄空时间为2140 s,砂泥流对桥梁结构的冲击力为11.96 kPa。该研究结果可为同类工程的安全评估和地质灾害防控提供参考,对尾矿库安全防控具有重大的实际意义。

As dangerous source of man-made debris flow with high potential energy,tailings ponds will cause serious casualties and property losses once the dam breaks.In order to study the impact of a tailings pond on the safety of a bridge,a geological generalization model and a numerical model for stability analysis of the tailings pond were established by means of on-site investigation,sampling,and indoor testing.The evolution of the dam break and the dam break were studied separately.The results show that in the non-seepage state,when the current dam body is in a saturated condition,the safety factor of the newly built dam is 0.987,and when the closed dam body is in a saturated condition,the newly built dam is in a saturated condition.The safety factor of the dam is 0.942;in the seepage state,when both the current situation and the closed dam body are in flood operation conditions,the dam breakage will occur.The minimum safety factor is 0.665,which is consistent with the signs of deformation of the dam body on site.When considering the earthquake situation,the stability of the dam body is significantly reduced due to the seismic load,and the potentially most dangerous slip surface is located in the newly built sub-dam.When the closed dam body is under the simultaneous action of saturated water and seismic conditions,the newly built sub-dam Dam break will occur,and the minimum safety factor is 0.759;the tailings pond burst may cause huge damage to highways and bridges.The main damage methods are impact,erosion,accumulation,and abrasion;during the evolution of the sand flow,the maximum sand flow rate is 1814 m^(3)/s,and the average velocity of the sand flow section is 0.99 m/s,the discharge time of the reservoir is 2140 s,and the impact force of the sand flow on the bridge structure is 11.96 kPa.The research results provide reference for assessment and local disaster prevention and control of similar projects,which is of great practical significance to the safety prevention and control of tailings pond.