基于LSTM的混凝土重力坝水下爆炸毁伤风险评估

Risk Assessment of Underwater Explosion‑induced Damage of Concrete Gravity Dams Based on LSTM

摘要:

为了提高混凝土重力坝的抗爆性能确保其安全运行，利用风险评估理论考虑爆炸载荷及坝体材料参数的不确定性，提出了基于长短期记忆网络（Long?Short Term Memory，LSTM）的混凝土重力坝爆炸毁伤风险评估模型。 选取裂缝贯穿度作为评价指标定量计算了不同爆炸场景下混凝土重力坝的风险失效概率，基于大坝发生轻微损伤的风险概率确定了安全防护距离，研究了浅水爆炸及深水爆炸对混凝土重力坝爆炸毁伤风险的影响，并进行了敏感性分析识别了关键变量。研究结果表明：混凝土重力坝的爆炸毁伤风险与爆炸荷载及坝体材料参数的不确定性密切相关；TNT 炸药当量一定时，随起爆距离的增加，混凝土重力坝的爆炸毁伤风险降低；随着起爆深度的增加， 坝顶发生严重破坏的概率降低，坝基发生严重破坏的概率增大；TNT 炸药当量是影响混凝土重力坝爆炸毁伤风险概率的关键变量。该研究为混凝土重力坝的水下爆炸风险评估及特殊时期抗爆措施的制定提供了依据。

Abstract:

To enhance the blast resistance of concrete gravity dams and ensure their safe operation, a risk assessment model for explosion-induced damage of concrete gravity dams based on long-short term memory (LSTM) was proposed, considering the uncertainties of explosion loads and dam material parameters using risk assessment theory. The crack penetration depth was selected as the evaluation indicator to quantitatively calculate the risk failure probability of concrete gravity dams under different explosion scenarios. The safety protection distance was determined based on the risk probability of minor damage of the dam. The influence of shallow-water and deep-water explosions on the explosion-induced damage risk of concrete gravity dams was investigated, and a sensitivity analysis was conducted to identify key variables. The results showed that the explosion-induced damage risk of concrete gravity dams was closely related to the uncertainties of explosion loads and dam material parameters. When the TNT equivalent was constant, the explosion-induced damage risk of concrete gravity dams decreased with increasing detonation distance. As the detonation depth increased, the probability of severe damage at the dam crest decreased, while that at the dam foundation increased. The TNT equivalent was identified as a key variable affecting the probability of explosion-induced damage risk of concrete gravity dams. This study provides a basis for the risk assessment of underwater explosions of concrete gravity dams and the development of blast resistance measures during special periods.