Effect of Blast Loading On Seismically Detailed Reinforced Concrete Column Cross-Section

Abstract

The vital need for the development of structural system that can survive the extreme events such as a blast load is becoming important nowadays. To date, the field of blast resistance design applied to civilian facilities is on its rudimentary stage. The conventional structures, particularly those above ground level, are not designed to resist blast load in most cases. Apparently, the design load of above ground structures are significantly lower than those produced by most explosions, making such above ground structures susceptible to damage from explosions. These facts are the main deriving forces for this thesis. The response of different column cross-sections and column lengths subjected to lateral blast loads is examined. Rectangular and circular cross-sections are used in both short and slender type for the study. Short rectangular column is further studied with different transverse reinforcement spacing and scaled distance subjected to combined blast and axial loading. The finite element package Abaqus is used to model RC column with the same boundary conditions. Short rectangular column is found to have better resistance than the others. Also short circular column has smaller lateral deflection than slender circular column. The result of the numerical study shows that the lateral reinforcement detailing has a significant effect on the behavior of columns under blast loading. Reducing the lateral reinforcement by 1/3 do not alter the result much but reducing by half the lateral reinforcement will reduce the lateral deflection significantly. The effect of axial loading is also investigated in the numerical study. As the axial load ratio increases, the blast resistance of the concrete columns increased. However, at high axial load ratios, the lateral resistance is more of the same.