复杂库型条件下高堆上游法尾矿坝三维渗流场分析

Three-dimensional seepage field analysis of high-stack tailings dam by upstream method under complex reservoir type condition

高堆上游法尾矿库由于水头高,渗径偏短,同时受复杂地形的夹持影响,在遭遇排渗设施失效或库水位升高等特殊工况时,坝体浸润线将抬升明显,进而影响到高坝运行安全。以国内典型的200m级上游法高堆尾矿坝为工程实例,针对该尾矿库利用三条沟谷同时堆坝这一特殊建库条件,开展尾矿坝空间渗流场研究工作,分析复杂地形下多沟谷渗流场的相互影响规律,揭示高坝浸润线易升高的关键区域及其抬升原因,并提出渗流控制措施。研究结果表明:1)受多区域渗水汇集、沟谷转角大、坝轴线收窄等复杂库型条件的综合影响,高坝渗流场的空间分布特征明显;局部浸润线相比周边区域抬高4~6m以上;2)坝体浸润线在堆积坝下半段往往贴近坝前水平排渗层内边缘通过;坝前排渗措施的有效设置对控制坝体浸润线十分关键;3)高堆尾矿坝坝体浸润线受库水位变化影响敏感,日常管理中应形成足够的库区干滩,确保尾矿坝安全运行。

Due to the high water head and shorter seepage length and the clamping effects of complex terrain, the immersion line of the tailings dam is uplifted obviously to further affect the safety of high dam operation, if encountering special conditions such as the failure of infiltration facility or rise of reservoir water level. Taking the typical 200 m upstream method high-stack tailings dam as an engineering example, the special building condition that using three gullies to simultaneously dam was used to carry out the research on the seepage field of the tailings pond and analyze the mutual influence law of multi-ditch seepage field in multi-ditch valley under complex terrain conditions, revealing the key areas where the high dam immersion line is easy to rise and the reasons for its uplift, and proposing effective measures for seepage control. The results indicated： 1） Affected by the comprehensive influence of multi-zone confluence seepage, large valley angle and shorter dam axis, the spatial distribution characteristics of the high dam seepage field is obvious, and the local immersion line is about 4-6 m higher than the surrounding area. 2） The immersion line in the lower half of the stacked dam is often close to the edge of the horizontal infiltration layer in front of the dam, the effective setting of the horizontal infiltration facility in front of the dam is very important to control the immersion line of the dam. 3） The immersion line of the dam body of the high-stack tailings dam is sensitive to the change of the reservoir water level, therefore enough dry beach should be formed in daily management to ensure the safe operation of tailings dam.