Integration of uncertainty modelling,structural reliability and decision theory to provide optimal blast protection to infrastructure

摘要

The loading and response of structures to explosive blast loading is subject to uncertainty and variability.This uncertainty can be caused by variability of dimensions and material properties,model errors,environment,etc.Limit state and LRFD design codes for reinforced concrete and steel have been derived from probabilistic and structural reli-ability methods to ensure that new and existing structures satisfy an acceptable level of risk.These techniques can be applied to the area of structural response of structures subject to explosive blast loading.Government spending on homeland security is projected to reach $300 billion by 2016.The use of decision theory to determine acceptability of risk is crucial to prioritise protective measures for built infrastructure.Probabilistic methods will be used to quantify the probability of damage or collapse of Reinforced Concrete (RC) columns.In this paper,Monte-Carlo simulation and probabilistic methods are used as the computational tool that incorporates uncertainties associated with blast loads and material and dimensional properties.The prediction of damage is based on load-bearing capacity of the structure.The structural reliability analysis calculates:(i) variability of structural response and (ii) damage and collapse risks RC columns subject to various explosive threat scenarios.If the protec-tive measure is increased stand-off,then structural reliability methods are used to assess risk reduction due to such a protective measure.Decision-support criteria based on net present value (net benefit) and expected utility to consider risk aversion are described herein.The key innovation is incorporating uncertainty modelling in the decision analysis.This analysis will then consider threat likelihood,cost of security measures,risk reduction and expected losses to compare the costs and benefits of security measures to decide the optimal protective measures to buildings.