高拱坝坝后侵彻爆炸毁伤效应分析

Damage effect analysis of high arch dam subjected to penetration explosion

高拱坝由于具有拱梁受力特性,其坝身往往较薄,而当薄拱坝坝后遭受侵彻爆炸打击时,高拱坝的安全将面临严峻的威胁。采用声固耦合方法模拟库水与大坝-地基动态耦合作用,光滑粒子流体动力学-有限元耦合方法(smoothed particle hydrodynamics-finite element method,SPH-FEM)模拟侵彻内部爆炸及大坝毁伤发展过程,建立了考虑混凝土高应变率效应的库水-坝体-爆炸耦合作用模型,研究了薄拱坝坝后遭受侵彻内部爆炸打击后的毁伤发展过程,探讨了坝后侵彻深度对薄拱坝坝身内部爆炸毁伤特性的影响,揭示了双曲拱坝上、下游几何特征对坝身侵彻爆炸破坏发展过程和毁伤机理。结果表明:高拱坝上、下游面的几何特征对大坝内部爆炸毁伤发展过程具有重要的影响;薄拱坝坝身遭受侵彻爆炸将对大坝安全构成严重威胁,且侵彻高拱坝中部破坏效应最大。

The dam body of high arch dam is often thin due to the stress characteristics of its arch beam.When the back of a thin arch dam is hit by penetration explosion,the safety of the high arch dam will face a severe threat.In this paper,the coupled acoustic-structural method is adopted to simulate the dynamic coupling between reservoir water and dam foundation,and the coupled SPH-FEM(smoothed particle hydrodynamicsfinite element method)is used to simulate the processes of internal penetration explosion and dam damage development.The coupling model of reservoir water,dam body and explosion considering the effect of high strain rate of concrete is established,and the damage development process of thin arch dam after being subjected to internal penetration explosion is studied.The influence of the back penetration depth on the damage characteristics of the thin arch dam is discussed,and the influences of the upstream and downstream geometric characteristics of hyperbolic arch dam on the development process and damage mechanism of penetration explosion damage of dam body are revealed.The results show that the geometric characteristics of the upstream and downstream surfaces of high arch dam have important influences on the damage development process of the dam internal explosion.The penetration explosion of the thin arch dam body will pose a serious threat to the dam safety,and the damage effect of penetrating the middle of high arch dam is the greatest.