Reliability-based load factor design model for explosive blast loading

The risk of damage to infrastructure and people is affected by airblast variability. Reliability-based design allows the decision-maker to select the level of reliability for a specific blast loading scenario. Reliability-based load factors are calculated where the nominal load is multiplied by the load factor to ensure that the actual load is equal to the reliability level. A design model for predicting reliability-based load factors is developed where model error, explosive mass and stand-off distance are random variables, and calculated reliability-based design load factors (RBDF) are independent of explosive mass, net equivalent quantity, angle of incidence, temperature or pressure. Hence, a design model describing reliability-based load factors are presented for reliability levels of 0.05 to 0.99, and for coefficients of variation of explosive mass and range each varying from 0.0 to 0.3. The paper then shows the significant effect that range and explosive mass variability have on RBDFs, and how this affects structural design and damage predictions for reinforced concrete columns and glazing.