In order to analyze the bridge strain signal under explosive load, the sym N wavelet basis function is selected by wavelet analysis method to conduct multi-layer decomposition and reconstruction of the corresponding strain signal, analyze the main characteristics of each frequency band signal, and discuss the frequency band range of the measured strain signal. The results show that the measured strain signal is mainly concentrated in the low frequency part, and the high frequency part is caused by various interference factors; The highest frequency of effective strain signal is mainly below 5KHz, which can provide theoretical reference for strain gauge selection during bridge strain measurement under explosive load.

Concrete piles are a common obstacle in an antilanding obstacle field. To research the damage ability of concrete piles with different shaped charges, penetration tests of concrete piles with different standoff distances (SODs) were carried out with explosively formed projectiles (EFPs) and jetting projectile charges (JPCs). The pressure was measured at different positions inside the concrete piles during the penetration process, and the failure mechanism and damage characteristics of the concrete piles were analyzed. The penetration velocity of the JPC was measured by placing reticular targets inside the concrete pile. The results show that the damage ability of JPCs to concrete piles is stronger than that of EFPs. When the SOD is in the range of 20∼50 cm, an EFP causes slight damage to a concrete pile. With the increase in SOD, the penetration capacity of JPCs increases, but the damage ability of JPCs decreases. When the SOD is 15 cm, a JPC causes severe damage to a concrete pile, and when the SOD is in the range of 20∼40 cm, a JPC causes moderate damage. When attacking targets with obvious side boundary effects, such as concrete piles, the SOD that results in the strongest damage is not the SOD that results in the strongest penetration ability.

To study the pressure load of the underwater explosion on the typical surface of a concrete structure, composition B were used to explode in water, and the shock wave pressure on the front, side, top and back of the concrete pile was measured. The theoretical peak pressure of shock wave at the same distance in infinite water was calculated. The results show that the peak pressure of reflected shock wave at the front of concrete pile is the largest, which is nearly twice the theoretical value of the peak pressure of reflected shock wave at the same distance in infinite water. When the shock wave continues to propagate on the side and top surface, the peak pressure on the side is higher than that on the top surface. The peak pressure of the shock wave diffused from the side and top surfaces on the back is smaller than that of the other surfaces.