Risk assessment and control of underwater explosive damage to concrete gravity dams

The consequences of explosive loads on concrete structures in hydraulic engineering are serious. To enhance their blast resistance, taking a concrete gravity dam (CGD) as an example, a risk assessment model for evaluating the explosive damage of CGDs based on the Long-Short Term Memory (LSTM) network is proposed, considering the uncertainty of explosion loads and dam material parameters. Two blast-resistant measures which are glass fiber reinforced polymer (GFRP) anchors and GFRP anchors + reinforced concrete protective slabs (RCPS), are proposed for controlling the damage risk of the CGD. The crack penetration ratio is selected as an evaluation index to quantitatively calculate the risk probability of CGDs under different TNT weights, detonation depths, and standoff distances before and after implementing blast-resistant measures. The safe protection distance is determined based on the risk probability of slight damage to the dam. The influence of RCPS thickness on the safe protection distance at the dam crest is also discussed. This research provides a basis for the risk assessment of underwater explosive damage to CGDs and the formulation of blast-resistant measures during special periods.