上游法尾矿坝地震响应及抗震加固措施研究

发布时间：2018-12-07 11:14

【摘要】：尾矿坝内堆存了易发生液化的饱和沙土材料,地震作用下尾矿坝易发生液化而丧失稳定性,危及下游生态环境。因此,研究地震作用下尾矿坝的动力响应、动力稳定性和地震液化,提出相应的抗震加固措施是十分必要和迫切的。本论文依托一上游法尾矿坝——云南省昌宁县鸡街子尾矿坝工程实例开展研究,主要包括上游法尾矿坝的地震响应、地震液化、坝体稳定性以及抗震加固措施等方面内容。论文具体研究内容为： (1)基于鸡街子尾矿坝工程地质勘察资料,通过现场试验以及尾矿材料的室内直剪试验研究,得到了尾矿和相关材料的内摩擦角和粘聚力指标值；(2)基于非饱和土流固耦合理论及渗流理论,研究了鸡街子尾矿坝的渗流规律；(3)采用经典极限平衡法及有限元强度折减法研究了鸡街子尾矿坝的静力稳定性；(4)采用时程分析法研究了地震作用下鸡街子尾矿坝的动力响应规律,提出了地震作用下尾矿坝的动力稳定性安全系数；(5)采用Seed砂土液化判别方法对地震荷载下鸡街子尾矿坝潜在的液化区域进行判定；(6)研究了不同抗震加固措施的抗震效果,针对鸡街子尾矿库提出了相对有效的抗震加固措施。论文研究结果表明：(1)尾矿库处于正常工况时,二维渗流计算结果与三维渗流结果相近；尾矿库处于洪水工况时,二维渗流计算数值普遍小于三维渗流计算数值；尾矿库非饱和区域越大,流固耦合效应对渗流的影响越显著；(2)M-P法计算结果与强度折减法计算结果相近；极限平衡法不宜应用于坝体潜在滑动面位置的精确求解；(3)鸡街子尾矿坝对输入的地震时程荷载反应较小,尾矿坝处于稳定状态,但计算最小安全系数较小,尾矿库的安全储备不够充分；(4)鸡街子尾矿库在地震作用下发生了震动液化现象,但液化对尾矿坝的稳定性影响较小。论文的创新性工作主要包括：(1)论文采用了三维有限元开展尾矿坝地震响应分析与研究,分析结果更符合实际；(2)论文针对地震作用下尾矿坝内潜在的失稳部位,提出了相对有效的抗震加固措施。
[Abstract]:The tailings dam is prone to liquefaction of saturated sandy soil materials. The tailings dam is prone to liquefaction and lose stability under the earthquake, which endangers the downstream ecological environment. Therefore, it is necessary and urgent to study the dynamic response, dynamic stability and seismic liquefaction of tailings dam under earthquake. Based on an upstream tailings dam-Jijiezi tailings dam project in Changning County, Yunnan Province, this paper carries out research, including the seismic response, seismic liquefaction, dam body stability and seismic reinforcement measures of the upstream tailings dam. The specific contents of this paper are as follows: (1) based on the engineering geological survey data of Jijie Zi tailings dam, the field test and the indoor direct shear test of tailings materials are carried out. The internal friction angle and cohesion index of tailings and related materials are obtained. (2) based on the fluid-solid coupling theory of unsaturated soil and seepage theory, the seepage law of Jijiesi tailings dam is studied, and (3) the static stability of the dam is studied by using the classical limit equilibrium method and the finite element strength reduction method. (4) the dynamic response law of Jijiezi tailings dam under earthquake action is studied by time history analysis, and the safety factor of dynamic stability of tailing dam under earthquake action is put forward. (5) the potential liquefaction area of Jijiezi tailings dam under earthquake load is determined by Seed sand liquefaction method. (6) the aseismic effect of different seismic reinforcement measures is studied, and the relatively effective seismic reinforcement measures are put forward for Jijiezi tailings reservoir. The results show that: (1) when the tailings reservoir is in normal condition, the results of two-dimensional seepage calculation are similar to those of three-dimensional seepage calculation, while the two-dimensional seepage calculation value of tailings reservoir is generally smaller than that of three-dimensional seepage calculation when the tailings reservoir is in flood condition. The larger the unsaturated region of tailings reservoir, the more significant the fluid-solid coupling effect on seepage flow; (2) the results of M-P method are close to those of strength reduction method, and the limit equilibrium method is not suitable for the accurate solution of potential sliding surface position of dam body. (3) the response of Jijiesi tailings dam to the input seismic time history load is small, the tailings dam is in a stable state, but the minimum safety coefficient is small, and the safety reserve of the tailings reservoir is not enough; (4) the vibration liquefaction of Jijiesi tailing reservoir occurred under earthquake, but the liquefaction had little effect on the stability of the tailings dam. The innovative work of this paper includes: (1) Three-dimensional finite element method is used to analyze and study the seismic response of tailings dam, and the results are more practical; (2) aiming at the potential instability of tailings dam under earthquake, the paper puts forward relatively effective seismic reinforcement measures.
【学位授予单位】：云南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TV649;TV312

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