WP 4

Work Package Leader:

Mr. Franco Corsi

The objectives are:

To optimise the thermal and structural behaviour of all tunnel components designed for active and   passive safety.

To increase the robustness and load bearing capacity under accidental conditions.

To assess the performance of the integral tunnel structure in all fire phases conditions: from ignition, through growth to the fully developed stage and the decay period.

To achieve a robust working/functioning complete system - including the effects of fire temperatures.

To reduce and limit non operational time and repair retrofitting work.

To evaluate existing technology with main emphasis on cost-benefit (including maintenance).

To establish safer design and to evaluate recommendations for optimal tunnel systems.

Technical tasks

Structural elements functional performance and load bearing capacity.

It is necessary to achieve better understanding and gain more insight in structural performance in fire of concrete load-bearing elements, with a view to be able in subsequent tasks to develop new mitigating measures to avoid or limit structural damage to an acceptable level and to provide fast repair methods.


Improving components functional capacity.

By means of numerical analyses and laboratory fire tests, data will be established for all individual elements regarding its resistance and functionality as a function of its exposure time. This data helps to point out possible improvements to currently available elements and to make recommendation for designing new ones. The different element with the best characteristics will be identified and, if appropriate, proposed for use in upgraded tunnels.


Innovative damage assessment and repair and recovery and retrofitting.

Essential therefore is to:

- assess the damage level very quickly;

- propose and apply adequate repair and recovery methods.

The rather hostile tunnel environment, in combination with the desired limited non-operational time, requires development of innovative FAST and ACCURATE damage assessment techniques.


Proposal of innovative solutions.

For tunnels where current system design is not suitable, alternative innovative solutions will be suggested. Alternative optimised configurations and advanced technological engineering solutions will be studied and verified. Indication how to achieve reductions and/or elimination of explosive spalling will be given.


Safety levels criteria evaluation / engineering guidance and implementation.

On the basis of previous task results a clear definition of safety levels of existing configuration and system design will be obtained.