防渗尾矿库地震稳定性和位移分析

发布时间：2018-12-14 19:33

【摘要】：随着人们对于尾矿中污染物的了解以及由于尾矿中渗沥液下渗导致环保事故的增多,越来越多的尾矿库开始采取防渗措施。由于我国防渗尾矿库多位于地震频发区,一旦地震发生震陷或边坡失稳事故,或者在地震作用下衬垫系统和渗沥液导排系统发生破坏,都会给环境造成巨大危害。因此,研究防渗尾矿库的地震稳定性和永久位移有着重要的工程意义。本文通过固结、直剪、动三轴等土工试验,获得了磷石膏的物理和力学参数,为磷石膏堆场静、动力稳定性分析提供依据。结合某防渗尾矿库工程实际,使用FLAC2D软件建立了有限差分数值模型,对采用粘土垫层防渗的尾矿库进行二维地震动力响应计算,分析其地震稳定性,并将计算得到的坝顶最大水平位移与传统简化方法的计算结果进行了对比分析。结果表明,通过有限差分数值模型计算的水平位移仅略大于简化方法的计算结果。参数分析表明:防渗垫层的抗剪强度对于尾矿库动力响应影响较大,其虽有一定的隔震作用,使得防渗层上部的最大水平加速度低于其下部的最大水平加速度;但随着防渗垫层抗剪强度的降低,尾矿库的失稳模式由经过尾矿内部的圆弧形滑动向经过防渗层的楔形滑动转变,尾矿库的稳定性下降,屈服加速度显著降低,永久性水平位移大幅增加,可能造成震陷等危害。本文研究结果对于地震区防渗尾矿库工程的设计有一定的实用参考价值。
[Abstract]:With the understanding of pollutants in tailings and the increase of environmental accidents caused by leachate seepage in tailings more and more tailings reservoirs begin to take anti-seepage measures. Because most of the anti-seepage tailing reservoirs in China are located in the frequent earthquake area, once the earthquake occurs earthquake subsidence or slope instability accident, or under the earthquake action of the liner system and leachate drainage system damage, will cause great harm to the environment. Therefore, it is of great engineering significance to study seismic stability and permanent displacement of seepage control tailings. In this paper, the physical and mechanical parameters of phosphogypsum are obtained through consolidation, direct shear and dynamic triaxial geotechnical tests, which provide the basis for the static and dynamic stability analysis of phosphogypsum stacks. A finite difference numerical model is established by using FLAC2D software to calculate the seismic dynamic response of tailings reservoir with clay cushion, and the seismic stability of the tailings reservoir is analyzed by combining with the engineering practice of a seepage control tailings reservoir, and the finite difference numerical model is established by using FLAC2D software, and the seismic stability of the tailings reservoir is analyzed. The calculated maximum horizontal displacement of the dam top is compared with that of the traditional simplified method. The results show that the horizontal displacement calculated by the finite difference numerical model is only slightly larger than that of the simplified method. The analysis of parameters shows that the shear strength of impervious cushion has great influence on the dynamic response of tailings reservoir, although it has a certain isolation effect, the maximum horizontal acceleration of the upper part of the impermeable layer is lower than the maximum horizontal acceleration of the lower part of the impervious layer. However, with the decrease of anti-seepage cushion shear strength, the instability mode of tailings reservoir changes from circular arc sliding through tailings to wedge sliding through impermeable layer, and the stability of tailings decreases and the yield acceleration decreases significantly. The permanent horizontal displacement increases greatly, may cause the earthquake subsidence and so on harm. The results of this paper have certain practical reference value for the design of seepage control tailing reservoir in earthquake area.
【学位授予单位】：上海交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TV649

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