强震作用下高拱坝抗震安全分析

Seismic safety analysis of high arch dam under strong earthquake

一大批高拱坝在我国西部强震区建设、运行,高拱坝抗震安全至关重要。本文采用混凝土四参数损伤模型,模拟高拱坝在强震作用下的抗震安全问题。通过超载地震加速度峰值,研究不同超载倍数下,高拱坝抗震安全性能。分析表明,在强震作用下,坝体靠近建基面及坝体中上部损伤值较大,且随着加载倍数增加,损伤值逐渐加大,分布区域亦相应增加,当超载地震加速度峰值倍数为2.0时,坝体已偏于不安全。研究给出了高拱坝坝面损伤分布情况,为高拱坝抗震安全评价提供一种新的思路。

Large quantities of high arch dams have been constructed and have worked in the high seismic southwest of China.The seismic safety of arch dams is of great importance.The concrete four-parameter damage model is used to simulate earthquake safety of a high arch dam subjected to severe earthquakes.Peak acceleration of earthquake is overloaded.Different overload ratios are analyzed to study the seismic safety performance of high arch dams.The analysis shows that under severe earthquake,nearby plane base surface and middle-upper part of dam,the damage is larger than those in other parts.The damage is gradually increasing with the load multiple increasing and the distribution area also increases accordingly.Under overload 2.0 times of the peak seismic acceleration,the dam is unsafe with the high arch dam surface damage distribution given.This paper provides a new train of thought for high arch dam seismic safety evaluation.