水下和空中爆炸时混凝土重力坝动态响应对比分析

摘要

There exist significant contrasts in shock wave propagation characteristics and dynamic responses of structures subjected to under-water and air explosions due to water and air's different physical properties and interface effects.A fully coupled numerical simulation model for a concrete gravity dam subjected to underwater and air explosions was built considering charge detonation,shock wave propagation,shock wave-structure interaction and structural response.The shock wave propagation characteristics from free-field explosions in water and air were compared.The dynamic response and failure modes of the dam in a typical underwater explosion scenario and an air one were investigated,respectively.The results showed that the dynamic response and damage level of a concrete gravity dam subjected to underwater explosion are significantly higher than those subjected to air blast with the same mass of charge;hence,more attentions should be paid to the shock wave propagation characteristics from underwater explosion and the subsequent response of dam structures.%由于水和空气的物理属性差异以及与爆炸产物的界面作用效应不同，使得水下和空中爆炸冲击波传播特性及其荷载作用下的大坝结构动态响应存在较大的差异。通过构建混凝土重力坝水下爆炸和空中爆炸的全耦合数值仿真模型，考虑炸药起爆、冲击波传播、冲击波与结构的相互作用以及结构的动态响应等复杂过程，在对比分析爆炸冲击波在水下和空中传播特性的基础上研究了水下和空中爆炸冲击波对大坝动态响应及损伤程度的影响。研究表明，水下爆炸冲击荷载作用下混凝土重力坝动态响应及损伤程度均较同等炸药量下空中爆炸冲击荷载作用时大；在研究水工大坝抗爆性能时，应重点关注水下爆炸冲击波传播的特性及大坝在水下爆炸荷载作用下的动态响应。