尾矿坝地震液化破坏机制及流滑运移特征研究

Tailings dam earthquake disaster with sudden and destructive characteristics, its seismic stability has become a mining security challenges. Soil liquefaction-induced deformation is the main factors that lead to the tailings dam earthquake damage, how to quantify the deformation of liquefied tailings is the key issue of the tailings dam seismic safety evaluation. Tailings dam seismic liquefaction studies pay more attention to the liquefaction conditions and influencing factors, and there is no report for the present fluid state characteristics of the liquefied tailings. This project take triaxial tests → theory calculation models→ physical models (shaking table models and the numerical models) → instance models (actual earthquake damage), as the technology route. The liquefied tailings fluid properties and flow characteristics are studied by using triaxial tests. On the basis, a liquefied tailings calculation model based on hydrodynamic theory is established and a calculation method of tailings dam earthquake liquefaction deformation is proposed. The liquefied tailings fluid dynamics is studied by using shaking table model test, to prove the liquid tailings flow slide transport characteristics. At the same time, the evolution of tailings microscopic fabric is studied in liquefaction process. Coupling analysis based on the macroscopic and microscopic to reveal the intrinsic link between the microscopic fabric parameters change with the macroscopic liquefaction phenomenon, the earthquake liquefaction destruction mechanism of tailings dam is comprehensively evaluated. The research results provide a theoretical basis and technical support for the antiseismic design and disaster prevention and mitigation decisions of tailings dam.

尾矿坝地震灾害具有突发性和大破坏性的特点，其地震稳定已成为矿业安全难题。液化引发土体变形是导致尾矿坝地震破坏的主要因素，如何合理量化液化尾矿的变形是尾矿坝地震安全评价的关键问题。目前尾矿坝地震液化研究更多关注液化发生的条件和影响因素，而针对液化后尾矿呈现流体状态的相关特性缺少研究。本项目采取三轴试验→理论计算模型→物理模型（振动台模型和数值模型）→实例模型（实际震害）的技术路线，进行三轴试验研究液化尾矿的流体性质及流动特性，基于流体力学理论建立液化尾矿的计算模型，提出尾矿坝地震液化变形计算方法；进行振动台模型试验，以液化尾矿的流体动力学特性为研究对象，探明液化尾矿的流滑运移特征；同时对液化过程中尾矿细观组构演化规律进行研究，基于宏细观耦合分析，揭示细观组构参数变化与宏观液化现象之间的内在联系，综合评价尾矿坝地震液化破坏机制。研究成果为进行尾矿坝抗震设计及防灾减灾决策提供理论基础和技术支撑。

尾矿坝地震灾害具有突发性和大破坏性的特点，其地震稳定已成为矿业安全难题。液化引发土体变形是导致尾矿坝地震破坏的主要因素，如何合理量化尾矿的变形是尾矿坝地震安全评价的关键问题。本课题一是利用动三轴试验系统，研究饱和尾砂液化后大变形特性，重点探究了围压、振动频率和密实度对大变形的影响；二是通过对尾矿坝潜在滑动体的受力分析，考虑饱和尾矿动孔隙水压力对坝体稳定性的影响，推导了尾矿坝地震时和地震停止时安全系数的计算式，探讨了动孔隙水压力对坝体地震时工作状态的影响，揭示了尾矿坝地震破坏机制；三是将液化后尾砂夹杂废水视为流体，对尾砂流滑运移特征、冲击特性及相关影响因素进行了室内模型试验。基于光滑粒子流体动力学（SPH）完成了三维尾矿溃坝流对下游构筑物冲击过程的模拟分析；四是为适应计算参数本身具有的随机性和未确知性，将可靠度理论引入尾矿坝地震液化评价中。以测试数据的统计分析结果为基础，应用一次二阶矩法建立尾矿坝地震液化分析可靠度模型，探讨了可靠度指标与抗液化安全系数之间的关系；五是为评估尾矿坝地震液化侧向位移值，评价坝体地震安全状态，构建适用的地震液化侧向位移分析方法，提出针对中小型尾矿坝，区分地震液化有限变形和整体破坏的极限值（即破坏标准）。研究成果可为进行尾矿坝抗震设计及防灾减灾决策提供理论基础和技术支撑。.课题较好地完成了申报书的研究内容，达到了预期目标。研究成果发表了12篇学术论文，其中2篇被EI检索，9篇在核心期刊上发表；授权实用新型专利3项；培养3名硕士研究生和1名青年科技骨干。