高应力条件下尾矿破碎特性及坝体稳定性研究*

高应力条件下尾矿破碎特性与坝体稳定性研究是高尾矿坝避免溃坝事故的重要参考。分析尾矿颗粒破碎过程中级配曲线的演化规律，提出采用BET测试颗粒比表面积以定量化表征颗粒破碎指标;在室内高应力三轴试验的基础上，阐述高应力条件下尾矿的力学行为，提出高应力条件下尾矿强度准则，并基于该准则对工程实例进行应用分析。结果表明:相比于常用破碎指标，从能量观点出发的BET法比表面积表征尾矿颗粒破碎更为合理;采用线性Mohr-Coulomb准则计算尾矿在低应力阶段的内摩擦角，采用幂函数Mohr强度准则计算尾矿在高应力阶段的内摩擦角;提出1套考虑高应力条件下尾矿强度折减的坝体稳定性分析方法，以供实际工程参考。

Study on tailings breakage characteristics and dam stability under high stress conditions

The study of tailings breakage characteristics and dam stability under high stress conditions is the important reference for high tailings dams to avoid the dam break accidents.The evolution law of the gradation curve during the breaking process of tailings particles was analyzed,and the specific surface area of the particles was measured by BET to quantitatively characterize the particle breaking indicators.Based on the indoor high stress triaxial tests,the mechanical behavior of tailings under high stress conditions was explained,and the tailings strength criterion under high stress conditions was proposed.Based on the tailings strength criterion under high stress conditions,the application analysis of engineering example was carried out.The results showed that compared with the commonly used breaking indicators,the BET method from the energy point of view was more reasonable to characterize the breaking of tailings particles.The internal friction angle of tailings in the low stress stage could be obtained by the linear Mohr-Coulomb criterion,and the internal friction angle of tailings in the high stress stage could be obtained by the power function Mohr strength criterion.A set of dam stability analysis methods considering the tailings strength reduction under high stress conditions was proposed for practical engineering reference.