【作者】 郭振世；

【导师】 仵彦卿；

【作者基本信息】 西安理工大学 ， 岩土工程， 2010， 博士

【摘要】 尾矿坝是堆存金属及非金属等矿山选矿废弃物的构筑物,其数量及坝体高度随国家对矿产资源的巨大需求随之快速增加。而尾矿坝溃坝造成人员伤亡和有害污染物下泄的事故屡屡发生,给人民生命财产造成巨大损失,对环境安全构成严重威胁。因此尾矿坝稳定及加固技术等已成为各国政府、矿山企业和学术界所关注的重大课题。本研究结合工程实践,在高堆尾矿坝物理学指标变化规律、高堆尾矿坝三维渗流控制优化、高堆尾矿坝三维静动力稳定性、尾矿坝排渗体淤堵对坝体稳定性影响、尾矿坝加高扩容关键技术研究及应用等方面进行了认真探索。并将其研究结果应用于尾矿坝加高、加固实践,得到如下主要结论：(1)通过深钻孔勘探揭露及多种原位测试结果分析,高堆尾矿坝深部的干容重指标要显著高于浅部,堆积坝体同一空间位置,同样埋深下干容重指标随时间明显增加(16年增长约10%),浅层渗透系数降低约6倍,深层降低约12倍；提出了高堆尾矿坝稳定性分析中可按前期、后期分区统计选取力学指标的观点并用于实践。(2)依据实测坝体勘探面,首次分区采用渗透系数,拟合实际排渗设施反演分析,建立三维非均质各向异性渗流数学模型,并预测分析坝体加高后渗透安全需要的排渗设施形式和数量。根据当前坝高及规划加高坝体在已建立的排渗系统作用下的渗控结果,对规划坝高增设排渗设施等多种渗流控制布置,经计算与分析,提出规划坝高时渗流控制的优化布置。(3)开展了三维静动力的稳定分析、地震参数复核及人工合成地震动加速度时程曲线,为动力分析提供了符合现场的地震参数。采用基于有效应力法的EFES-3D计算程序,对加高后的坝体应力应变场进行了数值模拟和坝坡稳定性分析,得出应力应变场分布和液化评价,提出了三维静动力稳定安全系数计算方法。(4)开展了尾矿坝排渗体淤堵机理的现场和室内试验,分析了排渗体淤堵程度对渗透稳定性的影响。排渗效率不小于70%,坝体浸润线可满足安全要求。提出并应用了防治淤堵的工程技术措施。(5)提出并实施了大口辐射井-水平孔-插板立体排渗降低浸润线及综合法加高加固坝体等关键技术且得到推广应用,提高尾矿坝体安全性,提高了尾矿库充填系数。更多还原

【Abstract】 Tailings dam is a kind of depository structure where mineral wastes from metallic and nonmetallic mines are piled. With’the great demand of our country for mineral resources, its number and height increased rapidly. However, tailings dam failures which frequently caused incidents including the death of the people and containment of the environment brought about huge loss to people’s life and property, as well as serious threat to environment safety. The stability and consolidation of tailings dam has become an important subject that attracts attentions of the governments, mining enterprises and academic world. Here, in combination with the eningeering practice, the variation law of physical index, the three-dimensional seepage control and optimization, the three-dimensional static and dynamic stability, the effect of drainage body clogging on seepage stability as well as the key techniques of heightening and storage increase of high tailings dam were explored and studied. The results have been applied to practice of the heightening and consolidation thereof. The main conclusions are as following:(1)The indexes statistics of deep borehole prospecting and the various in-situ tests results showed:The dry bulk density of deep part significantly was significantly higher than that of shallow part of high tailings part. At the same spatial depth, the dry bulk density index increased significantly with time (theγd increase was about 10%). Therefor, the theory that the mechanic index can be selected statistically according to time zone (early-middle-later) during the stability analysis of tailings dam was proposed and was put into practice.(2)The mathematical models were obtained by actual measuremeng of the dam exploration profile, zoning by permeability coefficient at the first time and inverse analysis through fitting the real drainage and seepage facilities. The drainage system complied with the safety demand of heightened dam was predicted including the forms and quantity. According to the seepage control results of the established drainage system at the present and planning height of the dam, the various seepage control facilities were added and the optimized seepage control layout of planning height was put forward through the calculation and analysis. (3)The three-dimension static and dynamic stability analysis was carried out, and the time-history curve of the dynamic seismic acceleration of the dam site was composed with the inspection of seismic parameters based on the three-dimension seepage control study, therefore the seismic parameters reflected the onsite situation was provided for the dynamic analysis. EFES-3D calculation program based on the effective stress method was applied to the numerical simulation of the stress-strain field and stability analysis of dam slope after the dam height was increased. Then, the stress and strain field distribution diagram and liquification evaluation were obtained and the calculation method of three-dimension static and dynamic stability safety coefficient was presented.(4)The laboratory as well as onsite tests were carried out on the mechanism of clogging during drainage and the effects of the clogging degree on the seepage stability was studied. The results showed the efficiency was more than 70% and the saturation line met the safety requirements. Further more, the technical and engineering measures on reducing and preventing clogging were proposed.(5)The stereo drainage system which including wide diameter radiation well, horizontal holes and flashboard was used to lower soakage lines with the comprehensive technology which was used to raise the dam were developed and applied in practice. It was turned out by the engineering verification that these key technologies were practical.This dissertation is supported by National Natural Science Foundation(10572090)-The coupling model research on the deformation-seepage-chemical process of variable saturated medium and Jinduicheng Molybdenum Group-scientific research project "Research on the Lixi tailings dam serve period prolonging and the environment protection in Jinduicheng".更多还原