RETOS Y TENDENCIAS DESARROLLO DE INFRAESTRUCTURA EN AUSTRIA Leonardo Rosas Sánchez Bogotá Agosto 9 de 2018
Table of content 1. Safety standards for road and railway tunnels 2. Upgrading the Alrberg Tunnel to current safety standards 3. Conclusions
1. Safety standards for road and railway tunnels 1.1 Dramatc events Mont Blanc Tunnel: Aftermath of dramatic events in tunnel, safety measures seemed to be inadequate Safety is approached in engineering terms through a logical sequence of analyses and evaluation, mainly of a numerical and quantitative type. On 24 March 1999, a HGV traveling through the tunnel from France to Italy caught fire, possible due to the engine overheating St. Gotthard Tunnel: On 24 October 2001, two heavy good vehicles (HGVs) that were traveling through the tunnel in the Swill Alps had an accident Shortly after collision, a fire broke out on one of the HGVs, and it spread rapidly to the other vehicle
1. Safety standards for road and railway tunnels 1.2 Fire in Mont Blanc Tunnel Operation problem: A HGV stopped 6 km into the tunnel (L = 11,600 m), when the driver became aware of the fire Within minutes the tunnel operators were aware of the fire 29 vehicles entered the tunnel before it was closed Four HGVs managed to pass, but the other 25 vehicles became trapped Nobody traveling in any of those vehicles survived Ventilation problem: Due to the prevailing wind direction (from the south) and the different ventilation regimes at either end of the tunnel, virtually all the smoke from the fire was carried out towards France As the airflow velocity was more than 1 m/s, the smoke did not remain stratified, and within minutes there was no fresh air in the tunnel downstream of the fire
1. Safety standards for road and railway tunnels 1.2 Fire in Mont Blanc Tunnel Size and impact of the fire: At the height of the fire, the blaze was estimated to have been about 190 MW in size, with temperatures dealt with after 5 days: Thirty-eight tunnel users and one firefighter died as a result of the fire, 27 in their vehicles, two in an emergency shelter (designated to protect life in the event of a fire) and the rest on the roadway trying to reach the France portal This was the greatest ever loss of life in any road-tunnel fire (except the Salang fire in 1982, which involved an explosion as well as a fire)
1. Safety standards for road and railway tunnels 1.3 Fire in St. Gothard Tunnel Safety concept: The tunnel (L = 16918 m) comprises a single roadway with two lanes, bored on a north-south axis, bored from Airolo in the South to Göschenen in the North A safety gallery runs parallel to the main tunnel on the east side Refuges are spaced every 250 m along the length of the tunnel, and these connect the tunnel to the safety gallery
1. Safety standards for road and railway tunnels 1.3 Fire in St. Gothard Tunnel Complexity of the ventilation system: It could be longitudinal, i.e. with supply and exhaust systems switched off Semi-transverse, i.e. with only air supply or only exhaust operating; or fully transverse, i.e. with both supply and exhaust operating In fire mode the ventilation system was set to fully transverse, having been in longitudinal mode before the fire
1. Safety standards for road and railway tunnels 1.3 Fire in St. Gothard Tunnel Failure of the ventilation system: Fresh air was drawn into the air ducts at the portals at both ends of the tunnel, while the polluted air was extracted at ceiling height On the eastern carriageway, the ceiling was still intact in places, but had partially collapsed and was supported by the concrete walls of the tunnel lining Smoke, toxic gases and a considerable amount of the heat produced by the fire were directed northwards along the tunnel The fire burned for approximately 24 hours After the fire was brought under control, the bodies of 11 people were found among the debris to the north of the incident location
1. Safety standards for road and railway tunnels 1.4 Safety Engineering Transport infrastructures constructed a decade or more ago are unsuited to meeting the demands of the increase in passenger and freight transport This leads to infrastructure safety-related problems: (1) dramatic cases: (2) investigations at levels that have not been reached in the past Dealing with infrastructure safety now calls for the introduction of risk analysis The scientific approach that allows the evaluation of all risk factors: the identification, monitoring and reduction of accidents Infrastructure safe operations will focus primarily on preventing accidents and secondarily on protection (reduce effects on users) New infrastructure: New infrastructures the safety criteria become rules for the definition of project input and performance standards Existing infrastructures: 1) Adaptation of the infrastructure from a structural and/or functional point of view 2) Operative procedures aimed primarily at guaranteeing steady performance levels over time and throughout the year 3) The adoption of systems to reduce the risk of harmful events and incorrect behavior
1. Safety standards for road and railway tunnels 1.5 Road Tunnel Safety Directve 54/2004/EC) On 29th April 2004, the Directive 2004/54/EC was adopted, relating to the Minimum Safety requirements for tunnels on the Trans-European Road Network Initiative for the improvement of road safety in tunnels: uniform outlook on safety and common safety levels within the European Union Directive s purposes: 1) Minimum safety requirements for all tunnels belonging to the trans-european road network longer than 500 m 2) Harmonization of tunnel safety organization in Member States, defining the roles and responsibilities of the various subjects involved; 3) Harmonization of road signs and marking
1. Safety standards for road and railway tunnels 1.5 Road Tunnel Safety Directve 54/2004/EC) Contribution of Alpine countries: Clear strategic lines and safety objectives Each technical rule is based on technical-scientific criteria (without details) For existing tunnels, risk analysis can be used to satisfy technical requirements
1. Safety standards for road and railway tunnels 1.6 Railway Tunnel Safety New standards: Clear reference standard for the objective and quantitative analysis of railway tunnel safety Transition from a logic of rigidly preset standards to that of quantified system safety objectives Optimal balance between the safety objectives to be satisfied and the relative technical and economic consequences Sufficiency of minimum requirements: Successful evacuation of passengers (self-rescue) in the hypothesis of a central fire and advance of the smoke wall through the tunnel Safety conditions are determined: Trend of the concentrations of toxic products from combustion Concentration of oxygen Visibility along the tunnel and passenger evacuation times
1. Safety standards for road and railway tunnels 1.6 Railway Tunnel Safety Risk analysis for railway tunnel safety: Risk analysis is proposed: (1) probability of occurrence; and (2) indicator of gravity Measures and devices for the reduction of the risk to be adopted, the analysis is repeated in order to analyze the residual risk Safety measures and devices that aim to reduce risk must distinguish (ref. UIC document Codex 779-9 Safety in Railway Tunnels ) between: Prevention measures Protection measures Measures facilitating the escape from hazard sites (self-escape) Measures facilitating rescue operations
2. Upgrading the Arlberg Tunnel to current safety standards 2.1 Current situaton The Arlberg road tunnel has a length of some 15.5 km and is in operation for more than 35 years: It is a single tube tunnel operated with bidirectional traffic, but carries a quite low traffic volume Hence, the construction of a second tube is not really cost effective The tunnel is equipped with a transversal ventilation system with remotely controlled smoke extraction dampers providing smoke extraction every 100 m The maximum distance between egress possibilities to a save environment is some 1500 m After 35 years in operation: Upgrading for the electromechanical installations is needed to meet the requirements of the EU directive and the state of the art of safety systems defined in the Austrian guidelines (RVS 09.02.31, 2014; RVS 09.02.22, 2014) According to the EU directive, the maximum distance between aggress must not exceed 500 m
2. Upgrading the Arlberg Tunnel to current safety standards 2.2 Tunnel system The Arlberg railway tunnel runs almost in parallel to the road tunnel: This railway tunnel is part of the TransEuropean (Rail) Network (TEN) and had also to fulfill the minimum safety requirements for such railway tunnels These regulations however require egress possibility to a safe environment every 1700 m The fulfillment of the national and international directives requires a construction of additionally 37 egress ways An erection of further cross passages between the rail and road tunnel proved to be not cost effective due to the high distance between two tunnels (up to 300 m)
2. Upgrading the Arlberg Tunnel to current safety standards 2.3 Evacuaton concept Based on the feasibility study the following solution was chosen: Between the existing cross passages to the railway tunnel the fresh air ducts will serve in future as egress ways: New egress possibility from the road level up into the egress way in the fresh air duct The chosen solution minimizes construction costs, it has big implications on existing vital systems like ventilation In addition special fire protection has to be foreseen for the false ceiling between road and fresh air duct mist system was selected to serve for this purpose
2. Upgrading the Arlberg Tunnel to current safety standards 2.4 Ventlaton current situaton The tunnel is currently equipped with a full-transverse ventilation system with six ventilations sections, two vertical shafts (736 and 218 m) and two portal stations: Each section is currently ventilated by one fresh and one exhaust air fan The ventilation scheme, where VS1 to VS6 denote the ventilation sections, F1 to F6 and E1 to E6, denote the fresh and the exhaust air fans
2. Upgrading the Arlberg Tunnel to current safety standards 2.5 Ventlaton future situaton Ventilation design is driven by the needs for ventilation in incident situations with fire (fire ventilation): Hence the driver parameter for ventilation design is the required smoke extraction rate during incidents with fire The usage of the existing fresh air fans for air injection is appropriate This requires the installation of Saccado type fresh air injection dampers (FAID) and sealing door within the fresh air duct The scheme of the upgraded ventilation system with the FAIDs and three additional jet fans (JF1 to JF3)
2. Upgrading the Arlberg Tunnel to current safety standards 2.6 Jet fans The advantage of this system is that existing fans can be used and structural adaptations inside the tunnel can be reduced to a minimum: Normally such big fans should be mounted in ventilation niches on both sides of the tunnel However, in the special case of the Arlberg tunnel it was considered that the opening of the tunnel lining which would be required for constructing the fan niches would be too risky and costly due to possible drainage and structural problems Hence a positioning of the fans at the ceiling in the region of the extraction duct proved to be an appropriate solution
2. Upgrading the Arlberg Tunnel to current safety standards 2.7 Ventlaton control concept As the tunnel is equipped with a fully transverse ventilation system smoke extraction will be performed by opening remotely controlled dampers in close proximity to the fire location: Smoke will be extracted in to the exhaust gas duct. However, smoke confinement needs active control of the air/smoke movement inside the tunnel On the basis of numerical simulations fire ventilation scenarios were simulated and the system capability checked: The design fire size for ventilation was chosen in accordance to the Austrian guideline RVS 09.02.31 with a heat release rate of 30 MW The numerical simulations were performed with a 1D model based on the conservation of mass, momentum and heat
2. Upgrading the Arlberg Tunnel to current safety standards 2.8 Ventlaton control numerical simulaton It is shown a scenario for a fire in ventilation section VS6: Close to the fire location a mass flow of 144 kg/s smoke/air is to be extracted In order to achieve symmetrical flow from both portals towards the extraction location the usage of the FAID1 and FAID2 as well as of the jet fans JF1 and JF2 is needed In addition air extraction is required in section VS6 In this particular case, various exhaust air and fresh air supply fans as well as the jet fans are needed at the same time in order to reach the required ventilation goal The remaining fresh air fans are needed to vent the escape route vie the fresh air duct
2. Upgrading the Arlberg Tunnel to current safety standards 2.9 Fire protecton of the structure The erection of an egress way to close to a possible fire source at road level poses the requirement of special protection of the structure: Various measures for structure protection are available Starting from application of fire resistant slabs to installation of water based systems The requirement for action as structure protection is given in the Austrian guideline (RVS 09.01.45, 2006) Basic design parameters are given in the Austrian guideline RVS 09.02.51, 2014: The system has to be designed in order to operate over a time of 120 minutes
2. Upgrading the Arlberg Tunnel to current safety standards 2.10 High pressure water mist systems High pressure water mist systems have proven to be an effective mean for fire suppression: The high pressure water mist system enables the water mist to penetrate into a fire in liquid form and result in cooling due to evaporation at specific locations High pressure water mist also effectively tills up the protected space and provides superior cooling, hence protecting surrounding equipment and structures
3. Conclusions 1. After dramatic events in various long tunnels, safety measures seemed inadequate. Thus, the European Directive 54/2004/EC represents a turning point in the field of safety in the use of transport infrastructures and tunnels in particular. 2. A scientific approach was implemented that allows evaluation of all rias factors (in terms of intensity and probability) for the identification, monitoring and reduction of accidents. 3. Due to Austria has developed many of its transportation infrastructure before the Directive, the challenges and tendency for the coming years are to upgrade the existing infrastructure in order to satisfy the minimum requirements based on economical feasibility. 4. The upgrading of the existing Arlberg tunnel has to fulfill the requirements posed in the EU directive on minimum safety of road tunnels. In addition, the upgrading has to be done under the focus of limitations of civil works. 5. For the development of new infrastructure in Austria, risk management has been used for the very beginning of a design process. Risk management and risk control are very useful
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