Damage grades of reinforced concrete bent structures against blast

To study the failure law of reinforced concrete bent structures under large equivalent explosions, the damage grades of the bent structures against blast were numerically calculated based on the explosion test with the maximum equivalent of 3 t TNT. The load parameters and structural dimensions of the 1/2 scaled model were obtained through dimensional analysis. Based on the Abaqus finite element software, the CONWEP method was used to achieve the blast loading. The failure modes of the structures, under the explosion loads with TNT equivalent 0.5 t and blast distance 33 m as well as TNT equivalent 3 t and blast distance 33 m, were calculated, respectively, and compared with the test results. Further, the failure patterns of the scale model under different overpressures and impulses were calculated by controlling the TNT equivalent and blast distance. The research results show that the middle column of the bent structure is prone to damage in the form of overall overturning under a lateral blast load; the calculated failure morphologies are in good agreement with the experimental ones, and the maximum relative errors of the characteristic displacements and characteristic corners are 5.6% and 4.6%, respectively. The overturning angle of the load-bearing column was used as the basis for the damage-grade division, and the calculated results were divided into three damage levels. The fitted overpressure-impulse and equivalent-distance curves can be used in the design of safety distance and warehouse capacity and the estimation of the damage degree of accidental explosion. © 2020, Editorial Staff of EXPLOSION AND SHOCK WAVES. All right reserved.