Experimental study on the elastic-plastic dynamic response of shallow-buried corrugated steel-plain concrete composite structures under long-duration plane blast wave loading

To study the elastic-plastic dynamic response characteristics of shallow-buried corrugated steel-plain concrete (CSPC) composite structures under long-duration plane blast loads, a series of tests were conducted in a large confined blast-resistant test facility using the plane charge explosion technique (PCET), and the dynamic response and deformation laws of CSPC arches, reinforced concrete (RC) arches and plain concrete (PC) arches under different blast loads were comprehensively compared and analyzed. The test results show that under this test condition, the plane air shock wave overpressure peak with the increase in charge is basically a linear growth, but the shock wave pressure duration of action and impulse growth rate gradually decreased, the test device simulated by the explosion shock wave pressure duration of the maximum action time of more than 340 ms. Comparing the differences in the dynamic response of the three structures, it was found that when the peak long-duration shock wave overpressure acting on the structure reached 0.09 MPa, the PC model had plastic deformation, and the combined reinforced concrete and CSPC structure exhibited fully elastic deformation. When the peak shock wave overpressure reaches 0.238 MPa, the RC model begins to show plastic deformation. When the peak shock wave overpressure increased to 0.315 MPa, all models produced significant plastic deformation. The deformation resilience of the CSPC composite structure under the above-mentioned blast shock wave load is greater than that of RC and PC structures, which have good deformation recovery ability and can effectively reduce the damage to the structure by blast shock. On the contrary, the peak structural vibration acceleration caused by the blast shock wave is greater in the CSPC combined structure than in the RC and PC structure, and the deformation rebound and oscillation of the corrugated steel plate is the main way of impact energy dissipation. The results of the study provide an experimental basis for the simulation of long-duration plane blast waves and the optimal design of CSPC blast-resistant structures.