Full Session with Abstracts
Extreme fire events in tunnels can cause catastrophic consequences with the loss of life and service disruptions. Focusing on load bearing capacity of tunnels, partial collapse or considerable damage to tunnel lining implies long duration closure times for repair and major socio-economic losses. Meanwhile, currently there are limited guidelines and code provisions on structural safety of tunnels under fire. Given the level of uncertainty involved in such extreme events, risk-based frameworks can be used to identify potential fire scenarios that are relevant to the structure and verify performance of the structure subjected to those scenarios. Engineered solutions to achieve acceptable fire safety leads to more efficient and cost-effective approaches while safety is explicitly verified. Therefore, the application of performance-based design approach, while benefits of which have been shown in design of buildings, can be used to develop engineered solutions for structural design of tunnel under fire. This presentation will discuss the motivation behind performance-based structural fire safety design of tunnels. Safety of two tunnel structures, with different shapes and cross sections, are studied for a set of potential fire scenarios. The level of damage to concrete lining is quantified and is related to target performance levels considering the probability of the fire scenario. Soil-liner interaction of the tunnel and uncertainty in concrete material properties are taken into account in the analysis procedure.