高拱坝坝肩接触爆炸毁伤安全评价方法

Safety evaluation method of a high arch dam with abutment suffered contact explosion

坝肩稳定是高拱坝结构整体安全运行的基础,尽管高拱坝由于拱形受力特性具有较高的承载能力,但坝肩在遭受爆炸荷载作用后极易发生局部毁伤破坏,从而影响高拱坝结构的整体稳定性。着重对高拱坝遭遇水下接触爆炸毁伤后整体的安全稳定评价方法开展了研究,以刚体极限平衡法为基础,针对坝肩的毁伤破坏特征及毁伤面积,提出了拱圈沿右拱端面抗滑安全系数的评价准则,探讨了拱端面的损伤破坏对高拱坝沿拱端面抗滑稳定的影响。结果表明:坝肩接触爆炸主要引起接触部位坝体的压缩破坏和邻近拱端面的剪切损伤,而拱端面的毁伤将直接降低拱圈沿拱端面的抗滑稳定性,并最终导致高拱坝整体沿拱端面滑动失稳。

Abutment stability is a fatal factor to the global safe operation of the high arch dam.Although high arch dams have high bearing capacity due to the characteristic of the arch structure,local blasting damage on abutment will affect the global stability of the dam.This paper focused on the overall safety and stability evaluation method of the high arch dam suffered underwater contact explosion damage.Based on the rigid body limit equilibrium method,the evaluation criteria of the anti-sliding safety factor were discussed considering abutment damage area and characteristics.The influence of the arch end face damage on the anti-sliding stability along the base surface was discussed.The results show that the high arch abutment mainly suffers compression failure around the initiation point and cracking damage on the adjacent base surface subjected to underwater contact explosion.Moreover,the crack damage of the base surface will directly reduce the anti-sliding stability of the overall dam along the base surface and finally causes the whole dam slides along the base surface.