Risk-based optimisation of fire safety egress provisions based on the LQI acceptance criterion

Life safety is the primary objective of fire safety design and is mainly ensured by an appropriate design of the means of egress, which reduce the risk to life. An unlimited reduction of this risk is not desirable since it would lead to an immense investment of resources. The Life Quality Index (LQI) acceptance criterion is a societal indicator that is used to judge the efficiency of safety measures to reduce the risk to life and can be used to optimise the investments into life saving measures. The risk is assessed by a probabilistic engineering approach that considers the fire development and the individual-based evacuation process as well as the associated uncertainties. Advanced uncertainty propagation methods are applied in order to face the difficulties by using computational expensive models and by using individual-based models. Sensitivity measures are applied to reveal the contribution of the uncertainties on the estimation of the risk. The approach is applied for a risk-based optimisation of the minimal required door width for retail buildings.