SAFETY HAZARD AND DAMAGE RISKS FOR MONOLITHIC WINDOW GLAZING SUBJECT TO EXPLOSIVE BLAST LOADING

摘要

The modelling of consequences to built infrastructure when subject to explosive blast loading is well developed; however, considerable uncertainty remains with respect to system response and explosive loading parameters. Through the use of probability and structural reliability theory, the uncertainty and variability of system and load parameters can be quantified, leading to quantitative assessments of the security risks associated with blast threats. In the present paper, structural facades are assessed - as these are structural and load-capacity systems that pose significant safety hazards when effected by blast loads. A new research tool is developed to predict damage and safety hazard risks following blast loading of monolithic glass. The software tool is called "Blast-RF"(Blast Risks for Facades). The tool's structural reliability analysis uses stress limit states and the UK Glazing Hazard Guide's rating criteria to calculate probabilities of glazing damage and safety hazards conditional on a given blast scenario. In other words, Blast-RF predicts the likelihood and extent of damage or safety hazard for a single window or for an entire building facade. The damage and safety hazard risks associated with annealed monolithic glass are predicted, for TNT and ANFO based VBIEDs. The reliability analysis considers the variability of explosive material energetic output, pressure impulse, glazing stress limit, fragment drag coefficient, glazing dimensions, stand-off distance and explosive weight. Results are presented for glazing in a typical existing multi-storey commercial building.