Reliability analysis of direct shear and flexural failure modes of RC slabs under explosive loading

Two loosely coupled SDOF systems are used to model the flexural and direct shear responses of one-way reinforced concrete slabs subjected to explosive loading. Incorporating the effects of random variations of the structural and blast loading properties, as well as the strain rate effect caused by rapid load application, failure probabilities of the two failure modes are analyzed. The model is capable of predicting the failure probability of the slab with random material and geometrical parameters and subjected to random blast loading. Considering the random variations of structural properties and blast loading, the failure probabilities of one-way RC slab designed according to BS 8110 (Stuctural use of concrete, parts 1 and 2 (1985)) are calculated. The effect of span length of the slab on its failure probability to blast loading is also investigated. Based on numerical results, a semi analytical boundary that separates the slabʹs flexural and shear failure modes is derived as a function of peak reflected pressure and duration of blasting wave.