某抽水蓄能电站碾压混凝土坝结构动力响应分析

Structural dynamic response analysis of a roller compacted concrete dam of a pumped storage power station

对某抽水蓄能电站碾压混凝土坝进行结构动力响应分析,对碾压薄弱层处理采用等效连续模型,将碾压薄弱层和实体层视为一均匀体,避免了薄弱层对自由剖分网格的约束,得到了碾压混凝土坝在15阶振型下的位移及应力状态。结果表明:在动力荷载作用下坝体上游侧基础灌浆廊道以下及坝体下游侧离建基面1/3坝高以上大部分区域顺河向处于受拉状态,其余部位大都处于受压状态;其中第1、5阶振型对顺河向位移影响较大。同时针对碾压混凝土坝弹模敏感性分析表明:坝体坝踵和坝址部位在规范谱下的应力幅值随着弹模的提高略有变化,但应力幅值变化幅度很小。静力与动力作用效应叠加后,静载-规范谱叠加的结果中,整个建基面的应力为压应力状态,未出现拉应力。

The structural dynamic response of a roller compacted concrete dam of a pumped storage power station was analyzed within finite element method.The equivalent continuous model was proposed to avoid the effect of the weak-layer to the mesh generation.The deformation and stress of the roller compacted concrete dam with the dynamic load of 15 order vibration mode were obtained.The results showed that the stress near the grouting gallery and the top of the 1/3 dam were tensile stress and other position were compressive stress.The 1 and 5 order vibration model reduced larger deformation along the river.Also the sensitivity effect of the elastic module of the dam was analyzed.The result showed that the stress of the heel and toe of the dam changed with the change of the elastic model under the specification spectrum,but the elastic module had weak effect to the stress of the dam.Based on the static dynamic loading stacking method,the stress of the foundation surface was tensile stress under the static loading-specification spectrum loading condition and there was none compressive stress.