基于能量耗散碾压混凝土重力坝地震损伤分析

Seismic damage analysis of a concrete gravity dam based on energy dissipation

采用塑性损伤力学对混凝土重力坝进行非线性动力分析,通过研究塑性损伤本构中滞回曲线的特点以及地震中重力坝裂缝发展特征和结构能量耗散机理,建立了包含能量特性的大坝整体损伤评价指标。通过分析发现强震作用下坝体上部的损伤是结构的主要损伤,地震中的能量以结构阻尼耗散能量为主,混凝土损伤和塑性耗散的能量所占比例不大,但与裂缝的发展有直接关系。提出的大坝整体损伤指标可以综合的反应结构的整体损伤程度,以此对结构进行抗震设计,可以提高结构的抗震性能。

Nonlinear seismic analysis of a concrete gravity dam was performed based on the plastic damage theory.Its hysteretic feature,energy dissipation ability,failure mechanism and characteristics were studied.A seismic damage assessment model considering damage energy dissipation was developed for describing the damage level of the dam under strong earthquakes.The results showed that the damage of the upper part of the dam is the main damage of the structure;the vibration energy and the earthquake responses of the structure are reduced effectively by the structural damping;little amount of the seismic energy is dissipated by concrete damage and plastic dissipation.The seismic damage assessment model could quantitatively evaluate the damage level of gravity dams under strong earthquake.