Abstract
The construction of road tunnels is an important part of road infrastructure. The operation of road tunnels has historically been accompanied by a number of extraordinary events. Fires are among the most dangerous ones. Individual countries create their own safety standards that mutually differ to a large extent. Some of the differences of the requirements for safety devices, including the requirements for their functionality, are compared and commented on in this chapter. Moreover, attention is paid to the use of asphalt surfaces on roads and sidewalks in tunnels. This chapter also describes the approach to fire ventilation in tunnels, one of the most significant safety devices. Special attention is paid to the choice of the strategy of longitudinal ventilation, which has been the subject of many discussions. This chapter outlines the possible directions for a solution in the future.
TopBackground
On the basis of the requirements of the Regulation of the European Parliament and Council (EU) no. 305/2011, which defines harmonized terms for the introduction of structural products to the market and cancels the Direction of the Council 89/106/EEC (Regulation of the EP and of the Council, 2011), the properties that the construction of road tunnels shall meet include requirements for fire safety. The mentioned requirements comprise the retention of the load capacity in the case of fire, the limitation of fire spreading inside and outside of buildings, providing for the evacuation and rescue of persons and securing the safety of fire and rescue units.
The minimum safety level requirements for tunnels in the European union is given by the European parliament directive 2004/54/ES, on minimum safety requirements in trans-European road networks. It stipulates the technical and maintenance requirements for tunnels longer than 500 m. (the EP and Council, 2004)
Key Terms in this Chapter
Road Tunnel: A transport structure that runs beneath the surface of the earth, under the sea or river and serves for road transport.
Fire: Undesirable combustion during which there was death, injury or endangering people, animals, material values or environmental damage.
Functionality of Safety Devices: The ability of safety devices to perform their functions in the event of an emergency.
Critical Flow Velocity: The velocity of the air flow in the tunnel, which controls the flow of smoke in the selected direction and prevents its spreading against stationary vehicles.
Emergency Incidents: Harmful effects of forces and phenomena caused by human activities, natural influences or accidents that endanger life, health, property or environment and require the execution of rescue and liquidation work.
Heat Output of Fire: The amount of heat released during a fire per unit of time.
Longitudinal ventilation: One of the forms of ventilation of road tunnels, which is intended to ensure the flow of smoke in the selected direction.
Critical Visibility: The limited value of visibility, which, when is achieved, assumes the possible panic and considerable difficulties in the evacuation process for people who are unfamiliar with the environment.
Safety Devices in Tunnels: A set of devices that participates in the creation of safe conditions in tunnels.