Experimental investigation of steel-concrete composite slabs subjected to underwater near-field explosion

Steel-concrete composite slabs are vital structural components in engineering facilities, exhibiting high shear strength, stiffness, and energy dissipation capabilities. However, few studies have examined steel-concrete composite slabs subjected to underwater explosions. This study compared the dynamic response and damage characteristics of single-side steel-concrete composite slabs, steel-concrete-steel composite slabs, and reinforced concrete slabs subjected to underwater near-field explosions through experiments. The results indicated that bubble loading exacerbated specimen damage beyond shock wave loading alone, highlighting its significance. Each specimen exhibited distinct damage patterns, including crack distribution, concrete crushing, spalling, and localized damage. Compared with single-side steel-concrete composite slabs and reinforced concrete slabs, steel-concrete-steel composite slabs exhibited the weakest dynamic response, with maximum displacement reduced by 53% and 38%, respectively. Furthermore, they exhibited superior integrity after the blast, exhibiting excellent anti-explosion performance. These research results offer valuable insights for the explosion-resistant design of underwater engineering structures.