【摘要】 堆石坝筑坝材料的动力特性参数对围压有较强的依赖性,在高坝动力响应分析中采用某一围压下的参数将导致明显的误差。本文利用非线性静力有限元法确定坝体各单元震前有效围压;然后利用各填筑土料在不同固结围压下的动力试验结果,对坝体内各土体单元按震前有效应力进行线性插值或外延得到各单元动力特性参数随应变幅的归一化曲线,最后,采用动力等价线性有限元法确定坝体的动力响应。经过多种方案计算结果的对比分析,表明综合考虑高土石坝应力分布的特点和填筑土料动力特性参数随应变幅变化规律的围压依赖性可较准确地评价高土石坝等价线性振动体系的加速度、动力特性参数的分布、永久变形等坝体动力响应及抗震性能评价指标。更多还原

【Abstract】 Since the material dynamic properties of rockfill are strongly dependent on the confining pressure,the adoption of material parameters for single confining pressure in dynamic response analysis for high rockfill dam may result in significant error.An improved approach taking the effect of confining pressure and stress distribution into account is proposed.In this approach the confining-pressure-interpolating curves are introduced to determine the nonlinear properties of each rockfill element based on test data by linear interpolation or extrapolation.Then,the dynamic equivalent linear FEM is applied to determine the dynamic response of dam.The comparison of calculation results show that the approach comprehensively considering the effects of stress distribution and the dependency of material dynamic parameters variation on confining pressure gives the more accurate assessment of the acceleration,dynamic parameters distribution and permanent deformation as well as the aseismic performance index of the rockfill dam.更多还原