- Titel11th International Conference Tunnel Safety and Ventilation
- ITnA-Reports Volume 105; May 09-10, 2022
- LicenceCC BY-NC
- AbstractAustria has a long tradition in the construction and operation of road and rail tunnels, a field where user safety and accident response management are becoming ever more important. Building upon the past success, this international symposium offers the possibility to exchange knowledge and to gain deeper insight into the newest developments in the following fields: * Ventilation: design for normal and incident operation * Risk analysis: evaluation of safety related measures / limits of ventilation systems * System tests for the commissioning of road and railway tunnels and recurring tests during operation * Operational experience of road und railway tunnels * Refurbishment and upgrading of tunnels under operation * Vehicles powered by alternative propulsion systems
Imprint; Preface; Contents10.3217/978-3-85125-883-7-00 Tunnel Ventilation and Safety, 10 Conferences – The Story so Far10.3217/978-3-85125-883-7-01 Road Infrastructure and Sustainability – How Does It Fit Together?10.3217/978-3-85125-883-7-02 Tunnel Ventilation and UN 2030 Sustainability Development Goals – we have a story to tell10.3217/978-3-85125-883-7-03The 2030 Agenda for Sustainable Development, adopted by all United Nations Member States, provides a shared blueprint for peace and prosperity for people and the planet, now and into the future. Politically tunnel projects must be seen and actually be responsive to the United Nations climate change agenda. This means we, as tunnel ventilation experts, must articulate the benefits and efficiencies of the ventilation systems we design, operate, and refurbish using this modern narrative. From energy consumption minimisation to control systems that will respond to deceased emissions – our emphasis must be on explaining our approaches focused on the principles of sustainability. If we do not focus on these messages, we risk catastrophic rejection of our projects on sustainability grounds. The biggest threat to tunnelling and tunnelling projects is our industries lack of focus on adequately promoting underground infrastructure contribution to achieving the UNs sustainability objectives of 2030 and transformational opportunities, in the face of climate change. This paper proposes a framework for articulating tunnel ventilation opportunities that embraces the United Nations 2030 agenda for sustainable development. Current Status of the Work in Piarc's Technical Committee 4.4 Tunnels10.3217/978-3-85125-883-7-04This paper presents the outputs of PIARC’s road tunnel committee of the current work cycle 2020-2023. Due to the new PIARC approach in this cycle to have more and earlier outputs, TC4.4 will deliver in total 13 outputs until the end of 2023. Current topics include: Increasing resilience of tunnels, management of urban and heavily trafficked tunnels, impact of new propulsion technologies on tunnel operation and safety, ITS in tunnels, update of the online Road Tunnel Manual, updating and improving of the DG-QRAM Software, organization of the 2nd International Conference on Road Tunnels Operation and Safety and organization of two International Seminars in Low- and Medium-Income Countries (LMIC). Tunnel Performance Test10.3217/978-3-85125-883-7-05The life cycle of a tunnel structure over 500 m officially begins for operation with the first opening in accordance with the Road Tunnel Safety Act (STSG) and thus after acceptance by the tunnel management authority. In the course of such an acceptance with an officially appointed and sworn expert, the tunnel is structurally and technically inspected for functionality and conformity with regulations. After the first opening, the tunnel is not tested any more across all trades until the next refurbishment according to STSG §§ 7 and 8 STSG. ASFINAG Performance Tests have been working against this since 2018. With the voluntary internal ASFINAG tests of the entire system, conclusions can be drawn about the life cycle of a tunnel system and traffic and tunnel safety can be increased. The aim of these tests is to check systems between partial and general refurbishment and to initiate any necessary measures to restore the approved system condition. NFPA 502: A Report on Standard Updates and Activity10.3217/978-3-85125-883-7-06The NFPA 502 Standard provides fire protection and fire life safety requirements for limited access highways, road tunnels, bridges, elevated higheays, depressed highways, and roadways that are located beneath air-right structures. The NFPA 502 three year cycle is closing and the next edition of the standard will be published in September, 2022. The revisions to the Standard are nearly finalized, so this paper will impart an understanding of what the key changes are. The subjects addressed in the revision cycle include these: 1. Updates to the Critical Velocity Calculations Annex; 2. Changes to criteria from prevention of backlayer to control of backlayer; 3. Updates to the Autonomous Vehicles Annex; 4. Updates to the Alternative Fuels Annex; 5. Application of NFPA 72 (Fire Alarms); 6. Updates to the Tunnel Categories; 7. Structural fire protection. On Smoke Stratification in a 1-D Tunnel Ventilation Model10.3217/978-3-85125-883-7-07Tunnel ventilation design and risk analysis rely on modelling smoke propagation. I often read that 3-D numerical models are required, commonly Fire Dynamic Simulator in combination with the egress model EVAC. But these simulations are costly. Design decisions are made following one simulation scenario with the design fire in a single location and with steady-state boundary conditions. 1-D models cannot represent the nature of the flow? This is where I disagree. The paper includes references to analytical and empirical models, as the underlying equations have been published elsewhere. Here, we concentrate on a simple model to represent smoke stratification as a function of the local flow velocity and smoke temperature. As a result, we have a 1-D numerical model that gives a plausible representation of tunnel aerodynamics, thermodynamics of the fire, moving and stopping vehicles, smoke propagation, stratification, and egress. Such a model must be validated against data from tunnel fires, fire tests and/or 3-D CFD simulations. Once validated, the computation of a fire scenario only takes a few seconds. This allows us to run multiple scenarios with a variation of boundary conditions for better system understanding and consequently for better design decisions. Fruhwirt, Daniel10.3217/978-3-85125-883-7-08Understanding smoke propagation and temperature stratification in tunnels during fire incidents is crucial in order to ensure the road user’s safety. To accurately predict these phenomena, numerical tools such as Computational Fluid Dynamics (CFD) are invaluable. We present in this work a CFD model, which features an improved workflow and turnaround time by utilizing an autonomous mesh generation technology. A high-quality mesh is generated on the fly and enables the use of adaptive mesh refinement (AMR) based on local flow gradients. To assess the proposed method, simulation results are compared with measurements from fullscale fire tests performed by the Institute of Thermodynamics and Sustainable Propulsion Systems (ITnA) at Graz University of Technology in the Koralm tunnel (Austria). Namely, temperature readings from several sensors were used as validation data, along with the observed maximum backlayering length. CFD Validation for Tunnel Smoke Control Design10.3217/978-3-85125-883-7-09With no reliable formula for determining minimum required upstream velocity to control smoke in tunnels, attention has turned to CFD for answers. However, CFD must be used with caution, as it produces many different answers, depending on the quality of the algorithms and coding, and how parameters and numerical models are selected. It is really only valid when the whole system of analysis (analyst + software + parameter/model choices) has been validated against known and relevant real fire scenarios. If the analyst is new, the software is different, solution parameters change, or there is no real case for comparison, perhaps it can no longer be relied on. A validation of a system of analysis against the best available tunnel fire data (Memorial Tunnel tests) is presented, with discussion on how different modelling options and software can affect the outcome, leading to conclusions as to how to model smoke control in tunnels that are not so different (in the physics and flow regimes present) to the Memorial Tunnel tests. How far the techniques might be stretched to different geometries or fire scenarios is also discussed briefly. Selection of a Road Tunnel Ventilation System Using Ventsim Software10.3217/978-3-85125-883-7-10Designing the ventilation of a road tunnel is a demanding process, as it requires considering many aspects. Usually, the ventilation system, devices, and location of the elements are selected based on legal regulations and appropriate guidelines. Nonetheless, it should not be forgotten that each road tunnel is an individual case. The designer’s main goal is to ensure safe and comfortable conditions for users. The analysis includes the operation of the ventilation system in a road tunnel for standard conditions and the case of emergency (occurrence of fire). In the study, VentSim software is used. Using this software allows simulating the flow of air during both normal operation and fire conditions. The paper presents the methodology of designing the ventilation system and the carried-out simulations. Based on the results, the operating parameters of the system and its individual components were determined. The model was prepared based on the construction concept, meteorological data for the surroundings, traffic forecasts, and traffic analysis for nearby areas. As the analysis shows, the use of numerical simulation makes it possible to predict airflow for changing conditions, which highly simplifies the designing process and increases the safety of tunnel users. On Heat Transfer Coefficients and Temperature Distribution in Longitudinally Ventilated Tunnel Fires10.3217/978-3-85125-883-7-11Various approximate methods, and guidelines, are followed by tunnel-ventilation designers in the process of sizing the ventilation system. Of particular importance are the heat transfer coefficients used in prediction of the temperature distribution during a fire event. This strongly affects the ventilation exerted trust, and induces a chimney-effect pressure in sloped tunnels. For this purpose, a one-dimensional numerical solution approach is used in this work to evaluate their values. In addition, processing of a selected tunnel-fire-test from the literature data is also used in order assess the heat transfer coefficients values from realistic fire-tests. The results are discussed for final conclusions. Methodology for Investigations on the Tunnel Climate in Long Railway Tunnels - Optimization of the Design Process for Cross-Passage Cooling Systems10.3217/978-3-85125-883-7-12The operation of long railway tunnels requires numerous technical installations. Parts of these installations react sensitively on thermal loads and dust loads and require protection from the tunnel atmosphere. In the case of modern twin-tube single track tunnels such components are often placed in utility rooms which are situated in cross-passages. In order to meet the temperature requirements of the utility rooms, cross-passage cooling systems have to be installed. Designing these cooling systems requires extensive investigations on the tunnel climate. This represents a big challenge, as information about the tunnel climate in long railway tunnels is rare. For this reason, a method to support the design process of cross-passage cooling systems had to be developed. The application of this method on a certain tunnel provided the required information for a data based system design of the cooling systems in the Koralmtunnel (AT). This includes both, details about the technical feasibility of ventilation and air conditioning systems as well as economic considerations. Empirical Validation of Seasonal 1D Temperature Predictions in a 9 km Nordic Train Tunnel10.3217/978-3-85125-883-7-13Reliable long-term predictions of tunnel temperatures are critical in several ways, such as for passenger comfort, buoyancy driven air flows, risk of ice formation, thermal loads on tunnel lining etc. In this work, IDA Tunnel temperature predictions are compared with long term measurements in a 9 km twin-bore train tunnel in Sweden. Comparisons were made with measured as well as computed tunnel air velocities. Predictions were in both cases in good agreement with measured data. Barometric pressure differences between the portals were shown to have a significant impact on results, as did the background deep ground temperature level. The Piston Effect Test Bench for the Grand Paris Express10.3217/978-3-85125-883-7-14The "Grand Paris Express" railway network is currently under construction. It has been very quickly predicted that piston effect created by train will be greater than the traditional Parisian metropolitan network and all other networks in the world. This piston effect will be reflected in the stations and in all the shafts positioned roughly every 800 m in the tunnels for the intervention of emergency services. These shafts are also used for ventilation for passenger comfort and safety. As a consequence, the equipment in the shafts will face with piston effect and will be subjected to strong variations in pressure. At reduced fan speed, it is expected the fans will be passed through with a negative airflow and also operated in negative pressure. Therefore, they will be operated in areas that are not defined by the usual. In order to characterize a "Grand Paris Express" type fan, Eiffage carried out a platform to test the behavior of a model fan to the train piston effect. This test bench has been designed to reproduce the train passage on a cycle representative of the estimated pressure variation. The fan is therefore operated with successive negative and positive forced pressure on hundreds of thousands of cycles to ensure the durability of the equipment on several years of operation. Rapid Fire Detection and Notification Using a Dual Thermal+Optical Camera10.3217/978-3-85125-883-7-15The latest fire detection standard of the Japanese Ministry of Land, Infrastructure, Transport and Tourism (“MLIT”) requires that a 0.5m2, 2 litre gasoline fire at a distance of 25m must be detected and reported within 30 seconds of ignition. The paper shows that this requirement can be met reliably by using 'dual' video cameras, each with both thermal and optical functionality. It then describes how this capability can be incorporated into tunnel monitoring systems. The effectiveness of the method is demonstrated by the results of nine tests in a full-scale tunnel, namely three tests for each of three rates of airflow, nominally 0, 2.5 & 5.0 m/s. Every fire was detected in less than 10 seconds, thereby far exceeding the MLIT standard. Also, the passage of hot body vehicles through the test tunnel did not trigger false alarms. In addition to describing the system and the tests, the paper discusses related issues of practical importance to tunnel operators. Experimental Study on Gender Difference in Mental Stress and Walking Speed During Tunnel Fires10.3217/978-3-85125-883-7-16To investigate the relationship between mental stress and walking speed in a smoke-filled tunnel, an evacuation experiment was conducted in a smoke-experience tent, where 16 students (8 males and 8 females) participated. The heart rate change rate before and during the experiment (Group 0: <1, Group 1: 1–1.2, Group 2: >1.2) was used as an index of mental stress. The mean walking speed in smoke of each group were calculated based on gender. At Cs = 0.5– 1.0 m-1, the mean walking speed values of the females of Groups 0, 1, and 2 were 0.72, 0.94, and 1.23 m/s, respectively. the mean walking speed gradually increased as the heart rate change rate increased. However, the mean walking speed values of the males of Groups 0, 1, and 2 were 1.05, 0.83, and 0.75 m/s, respectively. the mean walking speed gradually decreased as the heart rate change rate increased. This indicates that males and females possess different spatial cognitive styles, implying that the influence of mental burden on walking differs based on gender. On the Accuracy of FDS Smoke Propagation Models in the Context of Tunnel Risk Analysis10.3217/978-3-85125-883-7-17In the recent past the Fire Dynamics Simulator (FDS) has become one of the primary tools for fire- and smoke propagation simulation in the context of tunnel fire safety. FDS has been extensively validated for compartment fires but validation for tunnels is scarce. After a quantitative validation against a full scale fire test is presented, the paper demonstrates how specific numerical options, in particular the size of the CFD mesh, influence the accuracy of the smoke propagation results. By doing so the investigated FDS modelling concepts are related to achievable prediction accuracies as well as the expected computation times. This enables informed decisions about the choice of model characteristics based on the necessary accuracy and available computational resources for future tunnel fire consequence analysis, typically used in tunnel risk models. Upgrade of the German Methodology for Tunnel Risk Assessment10.3217/978-3-85125-883-7-18The currently used methodology of safety assessment of road tunnels in accordance with BASt booklet B66 “Sicherheitsbewertung von Straßentunneln”  dates from 2009, extensive knowledge has been gained when implementing and applying the developed method in risk analysis studies. Numerous research projects have provided new findings on parameters previously not considered. As some methodological elements and basic assumptions no longer correspond to the state of the art, it became necessary to re-analyze the methodology and to develop appropriate adjustments. The updated holistic approach is based on the current evaluation of incidents in German road tunnels as well as the state of the art regarding the assessment of road users’ risks in tunnels. The upgrade suggested as output of the BASt research project FE15.0663/2019/ERB1 funded by the German Federal Ministry of Digital and Transport deals with risk evaluation, frequency analysis as well as the consequences of collisions and fires in tunnels. The implementation of the proposed adjustments allows analyzing tunnel risks more realistically and improves the evaluation of a large number of safety measures. The present paper summarizes the main adaptations developed and their influence on the risk assessment of road tunnels. Influence of Alternative Energy Carriers on Tunnel Safety – A Quantitative Consequence Analysis10.3217/978-3-85125-883-7-19The composition of road traffic is nowadays clearly dominated by petrol and diesel powered vehicles. However, one of the major goals against further climate change is the decarbonisation of road traffic by the use of vehicles with alternative energy carrier technologies. The currently most promising ones are the Li-Ion battery-powered vehicles, fuel-cell-powered vehicles and vehicles powered with internal combustion engines using hydrogen or liquefied natural gas. Although the latter do currently represent only a small share of the total traffic, it can be assumed that alternative powered vehicles will soon take on greater significance. Therefore, a deeper understanding of possible additional risks, especially in considering incidents in tunnel structures, is of greatest interest and is currently investigated in various research projects, such as , , . In these projects, the focus lies only on one of the alternative energy carriers mentioned above. However, in order to obtain a thorough overview of relevant possible additional dangers as well as related consequences on the safety of tunnel users, the aim of the BASt-project FE 15.0675/2020/ERB  as well as of the present paper is to consider all relevant alternative powered vehicle types in order to identify possible need for adaption of the risk-analytical assessment method for road tunnels. To this aim, dangerous zones according to, for example battery fires, jet fires or vapor cloud explosions have been assessed by using numerical as well as analytical models. In the course of a detailed evacuation model, considering a large variety of agents with different velocities and respiratory volumes, the corresponding consequences of alternative energy carriers on tunnel users can be assessed. This paper will demonstrate and discuss in detail the foundation of the research project with focus on the evacuation simulation, as well as the resulting consequences analysis on tunnel users. The Application of Zone Modelling in the Risk Analysis of Tunnels with ARTU Software 10.3217/978-3-85125-883-7-20Cantene has developed a software tool called ARTU, acronym for “Risk Analysis in Tunnels”, that calculates the societal risk related to fire in tunnels. The tool combines probabilistic and deterministic approaches, including different sub-models: 1D fluid dynamics, queue formation, egress, interaction between fluid-dynamic conditions and people. Recently, a new version has been released, that includes zone modelling in the representation of fluid dynamics. Zone modelling makes it possible to represent phenomena like back-layering and smoke stratification that cannot be represented by 1D fluid-dynamic tools. These phenomena are particularly significant in the first phase of the fire, when mechanical ventilation has not reached the nominal airflow and the egress takes place. The stratification of smoke has particular importance in tunnels without mechanical ventilation due to the fact that the fire products move undisturbed. A zone modelling tool developed by Lund University was chosen and many adjustments were made along with the developers in order to make the software suitable to the tunnel fire application. The areas of applicability of the tool were also investigated. As a results, the zone modelling software has been integrated into ARTU, in order to automatically manage a multiscale analysis depending on the characteristics of the analysed tunnel. Fierce: A Cost Benefit Analysis For Tunnel Fore Safety10.3217/978-3-85125-883-7-21The Belgian fire engineering consultancy FESG – A Jensen Hughes Company - has been developing a risk assessment framework for tunnels called FIERCE (Fire Integrated Environment for Risk Comprehension and Evaluation) in cooperation with Ghent University. The goal of the framework is to develop a probabilistic approach towards fire safety measures in tunnels taking into account specific fire safety measures (sprinklers, water mist systems, ventilation) but also structural and financial considerations. The framework couples, CFD, 1D and evacuation simulations in order to asses the impact of a tunnel fire in terms of potential casualties. In order to evaluate the structural damage and subsequent downtime a finite element model of a representative tunnel was built in ‘SAFIR’. This model was subjected to several fire curves, with a heating phase conforming to the RWS curve and an exponential decay phase. The evaluation of the damage and associated cost was done by mapping the depth of the 300 °C isotherm and residual deformations at the end of the decay phase to a damage state leading to an assessment matrix correlating the fire curve and the damage state. The damage state was subsequently linked to a repair cost as well as a cost associated with the unavailability of the tunnel. Influence of the Redundancy of Tunnel Ventilation Systems on the Availability of Road Tunnels10.3217/978-3-85125-883-7-22Tunnel ventilation plays a significant role in road tunnel availability. Especially in single-tube, but also in twin-tube road tunnels with transverse ventilation, the failure of an exhaust fan often leads to complete tunnel closure – at least in Austria. Comparison of international guidelines shows that different countries have different specifications regarding exhaust fan redundancy for transverse ventilation systems in tunnels. Almost all stipulate the need for redundancy in the design and operation of transverse ventilation systems. The Austrian guidelines and regulations are the only ones of those investigated not containing information on the requirement for a redundant ventilation system. Increasing the availability of road tunnels through a redundant ventilation concept is always associated with increased investment costs. However, these are justified when considering the loss of revenue as a result of tunnel closure. Redundancy can be achieved through various approaches. On the one hand, redundancy can be achieved by setting up additional fans in parallel; on the other hand, a redundant ventilation system can be achieved by using structural solutions. In future there will be an increasing need to ensure the availability of major road networks. It is therefore necessary to update the Austrian guidelines and regulations to make them state of the art. Validation of a Model Road Tunnel Using Fire Experiments Data10.3217/978-3-85125-883-7-23This paper describes the validation of a model tunnel designed for investigations on the design and operation of ventilation systems in road tunnels. The model tunnel in a scale of 1:18 allows flow visualisation and velocity measurements via particle image velocimetry technique (PIV). For isothermal investigations on fire scenarios, a buoyant helium-air-mixture is injected into the tunnel. Analogue scaling based on the preservation of the Froude number is used to correlate the results to real scale. Two experiments with mechanical longitudinal ventilation from the “Memorial Tunnel” test program were considered suitable for validation. The investigations were carried out in parallel experimentally with the model tunnel and numerically with the Fire Dynamics Simulator (FDS). The validation comprised a qualitative comparison of the smoke propagation and a quantitative comparison of vertical flow profiles in the tunnel axis to the original data. Overall, a good agreement with the original data was found in the evaluation of the results, so that a successful validation was assumed. The results show that it is possible to obtain similar flow characteristics applying analogue scaling in fire scenarios including the operation of model jet fans. Egress-Doors in ÖBB Railway Tunnels – Basics, Decisions, Recommendations10.3217/978-3-85125-883-7-24Increasing demands on a modern public transport infrastructure result in ever more extensive and complex projects including long tunnels. This usually also entails increased expenditure on rail technology equipment (including control and instrumentation systems and sensors). The aim of the overall rail tunnel system must be to ensure that railway operations must be safe, punctual and, as far as possible, uninterrupted. Aspects of maintenance, servicing and renewal must never be forgotten in this context. Emergency exit doors represent an important element in a rail tunnel, especially in the event of an incident for people fleeing and seeking for safe areas. It is of great importance and in many aspects a great challenge to define reasonable requirements for egress doors with regard to statics, serviceability, fire protection, operability, among others. Such requirements are finally often associated with compromises. Recommendations Towards the Standardization of the Ventilation Equipment in Road Tunnel10.3217/978-3-85125-883-7-25The road tunnel safety regulations specify the requirements of the ventilation system to achieve an acceptable level of risk in the tunnel, but they do not provide specific guidelines about the standardization of the equipment to be installed. This is an important point that must be taken into account to reduce the life cycle cost of the ventilation equipment throughout its lifetime, improving its maintainability, compatibility and integration with other systems. The present paper summarizes the outcome document, recently released by the Spanish National Committee of PIARC, assessing minimum requirements and recommendations towards the standardization of the ventilation equipment in road tunnels and the advantages linked to this standardization. On The Risk of a Pressure Vessel Explosion Inside Road Tunnel10.3217/978-3-85125-883-7-26Biogas and hydrogen are two renewable fuels that are needed in a transition from fossil fuels. Biogas and hydrogen tanks are equipped with a melt fuse that should release in the event of fire. However, on a few occasions, both nationally and internationally, the tank failed and the high pressure compressed gas was released instantaneously causing a pressure vessel explosion. If the explosion occurs inside a tunnel, the problems related to the pressure wave will be even more challenging, so the question whether the rescue service should be allowed to enter the tunnel has been raised, in particular with regards to the risk of hearing impairment. The Swedish civil contingency agency (MSB) takes such a stance. However, there are many uncertainties and assumptions that lead to such a decision that may need to be further discussed. It is argued that the limit value of 200 Pa is too low for such short and rare source of noise that a pressure vessel explosion is, and that such a decision also must consider the low likelihood of occurrence. A distinction should be made between pressure limits that has an immediate damaging effect and those which causes hearing damages from long-term exposure. Determination of Aerodynamic Loads in Rail Tunnels Using Measurements10.3217/978-3-85125-883-7-27When a train passes through a tunnel, pressure variations are generated which propagate along the tunnel at sonic speed and are reflected back at portals into the tunnel. These pressure variations may cause aural discomfort or, in the worst case, aural damage to train passengers and train staff and will produce transient loads on the structure of trains and the infrastructure components.  To define a clear interface between the subsystems of rolling stock and infrastructure, the traininduced aerodynamic pressure variations inside tunnels need to be known and limited. In order to specify and to limit the train-induced aerodynamic pressure variations inside tunnels, reference cases for rolling stock assessment are defined.  The increase of the speed limit up to more than 200 km/h for trains of VR Group (Finland) on coastal line (between Helsinki and Turku) in the unrestricted mixed rail-traffic operation required analyses and measurements regarding possible pressure loads. In this process, the relevant aerodynamic properties of the rolling stock are determined based on full-scale tests and compared with the directives of TSI and national directives. This paper describes the test procedure with sophisticated in-house developed pressure measurement device. The difficulties of pressure measurement using differential pressure sensors especially for this application is pointed out and a new solution is shown. Increasing Safety and Security by Using Modern Interdisciplinary Approaches for Underground Facilities10.3217/978-3-85125-883-7-28In the last couple of years, the need for extended safety and security methods in underground facilities for users, operators and emergency services became more and more important. Especially when it comes to terroristic attacks or accidents in underground structures where toxic gases and hardly any visibility can be part of, emergency services need to be as good as possible supported and protected. Therefore, various projects starting with a robot for mapping, augmented/virtual and mixed reality applications or navigation systems are carried out at ZaB - Zentrum am Berg in Eisenerz, a tunnel research, development, training and education facility, belonging to the Montanuniversität Leoben. This enables safety-related research without prejudice to the necessary operating times and high availability of conventional traffic tunnels. For the generation of a situational picture, the 3D representation of the underground branches of the facility, the recording of the number, the whereabouts of the tunnel users and the effective range of the sensors integrated in the operational and safety systems (BuS) are necessary. The goals also include positioning systems that allow real-time position determination despite darkness, smoke and very high temperatures. The presentation deals with research projects in the above-mentioned fields and some first findings. Feasibility Study into the Implementation of Zero Flow Tunnel Ventilation in the Schiphol Kaagbaan Tunnel10.3217/978-3-85125-883-7-29The Schiphol Kaagbaan tunnel had to be refurbished to meet the European Standards. Due to secondary requirements from stake holders, an investigation was started to determine whether removing the evacuation corridor and using a Zero Flow Ventilation strategy was a viable option. Three steps were taken to reach a final design choice. In the final step, the Feasibility Study, the two most decisive requirements of the authorities were 1) to prove the concept through a CFD-simulation and 2) to prove the equivalence of the Zero Flow Ventilation compared to a traditional evacuation approach. Due to remaining risks it was eventually decided to adapt stake holder requirements and implement an adapted evacuation corridor for egress. Ventilation Strategy and Design of Intertwining Tunnelramps, Oosterweel Link Antwerp10.3217/978-3-85125-883-7-30The Antwerp Oosterweel Link will consist of 5 intertwined TERN-tunnels (Trans-European Road Network tunnels), which will be, together with underpasses and depressed highways, all operated, controlled and secured by an integral safety concept. The most interesting tunnel complex of the Oosterweel Link, in terms of tunnel safety and tunnel ventilation, are the 2x2 stacked Kanaalzone tunnels. Near the Oosterweel junction intertwining ramps of the Kanaalzone tunnels create a specific geometry regarding tunnel safety and smoke control. The paper presents analyses of the preliminary design of the ventilation system of the Kanaalzone tunnels, comprising 74 jet-fans, and the accompanying ventilation strategy. The following steps in analyzing the smoke control can be determined: • basic ventilation design, based on probabilistic analysis; • quasi one-dimensional pressure balance relations; • cold (smoke-free) CFD-simulations to analyze the system behavior in detail; • hot-run CFD-simulations to analyze the smoke behavior and to optimize the ventilation strategy. Relevant preliminary results are: • Full jet-power on all fans is not always the best solution for smoke control in intertwined tunnel tubes. • Air balances between the tubes are important for effective smoke control in interconnected ramps and are affected by many parameters. • Interconnected tunnel tubes require a ventilation strategy on cluster level instead of tube level. Risk-based Ventilation Design Study for the LA Linea Tunnel10.3217/978-3-85125-883-7-31With a length of 8,650, the La Linea tunnel is the longest road tunnel crossing the central Andes mountain range in Colombia, with one tube for unidirectional traffic, connected via several cross passages with the parallel rescue tube. In 2016, at the beginning of the study, the civil works were concluded and the tunnel equipment had to be defined. According to relevant regulations and guidelines, the tunnel would require a transversal ventilation system. However, in the tunnel were no provisions for the implementation of such a ventilation system, respectively an intermediate ceiling for an air duct. In the ventilation study, different ventilation concepts were investigated. The aim was to identify the most appropriate ventilation system for normal operation and in case of fire. The equivalency of each alternative ventilation system including additional required risk-mitigation measures was investigated by a detailed quantitative risk assessment study. Thereby, the Austrian Tunnel Risk Model (TuRisMo) according to RVS 09.03.11 was used as a decision-making tool for the ventilation design and other safety-related aspects. The results obtained from the quantitative risk assessment study as well as the ventilations study show that the longitudinal ventilation system is the best and most suitable ventilation concept for the La Linea tunnel. Testing the Thrust of Jet Fans in a Wind Tunnel10.3217/978-3-85125-883-7-32In this research item we present a comparison on the calculated theoretical thrust of jet-fans and the values measured on a test station located within a high-velocity wind tunnel. The aim of this research was to perform a direct measurement of the thrust of the jet fan, along with the electrical parameters of the fan motor and direct velocity measurements in the jet fan stream, in an environment with a pre-defined air velocity (wind tunnel). The research was performed on two types of jet-fans ((1) 355mm diameter, approx. 37 N nominal thrust and (2) 50 mm diameter, approx. 2,8 N nominal thrust). The jet fans were placed in a boundary layer wind tunnel, in a test section of approx. 4 x 3 x 10 m (W x H x L). As the wind tunnel has a rectangular cross section, different locations of the jet-fans were tested (bottom, middle), to unravel the effect of the configuration factor on the jet fan performance. The inlet air velocity varied from 0 m/s to 20 m/s. The goal of this research was to identify the performance characteristic of jetfans, related to the ambient air velocity. This subject is important in the estimation of the jetfan performance in analytical methods (such as PIARC manual) or in 1D modelling systems. Furthermore, the estimation of such performance is highly relevant to the use of jet-fans in ventilation ducts, as a mean to reduce the required operational pressure of exhaust fans in a long tunnels with transversal ventilation systems. The presented work will give an overview of the standardized methods for measuring and calculating the thrust of jet-fans, the results of the measurements performed in the road tunnel and a numerical analysis of a long exhaust duct with jet-fans installed (with and without modifications introduced after the wind tunnel tests). Measurements and CFD Calculations with a Mojet and a Conventional Jet Fan10.3217/978-3-85125-883-7-33A series of measurements were undertaken with a 1.25m internal diameter, fully reversible jet fan in a factory and in the Rendel Street branch of the Mersey Queensway tunnel in Birkenhead, England. The jet fan was fitted with conventional and shaped (MoJet) silencers on both sides of the fan. The MoJet silencers were designed to deflect the airflow away from the tunnel soffit, in order to reduce the friction between the discharged jet and the soffit. The measurements showed an increase in the in-tunnel MoJet thrust of nearly 30%, compared to the conventional jet fan. The power consumption figures of the MoJet and the conventional jet fan were approximately the same, both in factory tests and in the tunnel, within the defined uncertainty limits. The measured tunnel velocities were very close to the results of detailed 3D CFD calculations using ANSYS Fluent, which incorporated the full geometry of the jet fan (including the rotating blades) and the tunnel. Our measurements imply that the MoJet can be employed to reduce the number of jet fans and to decrease the power consumption required for longitudinal tunnel ventilation. Best Practice for Selection of Fan- und Drive Technology in Tunnel Ventilation Applications10.3217/978-3-85125-883-7-34When designing and defining the ventilation systems of road tunnels and safety tunnels, the question of possible combinations of fan and drive technologies and their evaluation regarding technical realisation and economic efficiency very often arises. A well-founded decisionmaking process for the selection of suitable combinations is only partially available and therefore, selection is often based on personal experience and preferences. The FEDRO research project AGT 2015/005 addresses this issue by presenting the relevant fundamentals such as an overview of typical fan and drive technologies, the aerodynamic al requirements issued by the Swiss design codes as well as grid-compatibility requirements. The start-up currents as well as the harmonics related to the most common drive technologies are determined for typical ventilation applications by means of on-site tests. Based on these fundamentals, aerodynamic and electric selection processes are developed, allowing to determine the suitable combinations of fan- and drive technology for a specific project. The aerodynamic selection process assesses e.g., the need for multiple operating points for an axial fan or the impact on longitudinal airspeed. The grid compatibility assessment analyses the voltage drop at start-up and harmonic interference, based on the effective, project specific grid topology. The following evaluation process allows to identify, within those suitable combinations, the technically and economically most interesting solution. Within this evaluation, technical aspects (aerodynamics and system-integration) as well as life-cycle cost for fans, drives and wiring are considered. These costs include initial investment, maintenance as well as intermediate replacements when components do not fulfil the needed lifetime. The developed best practises are transparent and easy to use and therefore a useful tool when designing a road tunnel ventilation system. Every Second Counts - The Safety of People and Goods in Tunnels. Best Practice: Innovative Fire and Security Solution Using the Example of "Zentrum am Berg".10.3217/978-3-85125-883-7-35Tunnels are among the most demanding environments for fire safety technology and require careful planning and rigorous testing before commissioning. From road tunnels to subway and railroad tunnels, these structures serve as an integral part of modern infrastructure and need to remain operational around the clock. The operational requirements, difficult-to-access installations and the safety of both the people and goods that pass through tunnels, pushes the expectations of fire safety equipment, software and knowhow to an even higher level. To obtain approval for using the automated fire detection, the company must prove that the maximum fire detection time according to RVS (Guidelines and Regulations for Planning, Construction and Maintenance of Roads in Austria) is not exceeded. For tunnel projects this test was essential to be able to deliver automated fire detection in Austrian tunnels. An Affordable & Sustainable Alternative: LED Retrofit Tunnel Lighting 10.3217/978-3-85125-883-7-36 Ventilation in Short Tunnels as a Risk Mitigation Measure: "A short tunnel can be as dangerous as a long one"10.3217/978-3-85125-883-7-37When a tunnel capacity is foreseen by design and in operation results in a higher one, which produces almost permanent queues inside a tunnel, with a combination of light and heavy vehicle traffic, and an emergency management protocol mismatched to the reality of the operation, whether it is a short or long tunnel, with two-way or one-way flow, it is necessary to revisit the concept of tunnel classification based on its length and traffic volume, because a short tunnel can be as dangerous as a long tunnel". Normally, tunnels between 50 m or less and up to 250 or less than 500 m are defined as short tunnels in the standards that regulate and legislate on road tunnels worldwide. It is also possible to intuit a priori, that short tunnels, being of really minimum lengths, if compared with tunnels defined as long (1000 m and above), do not present comparable risks as those that would be found in the latter. Therefore, the attention to any particularity that a short tunnel may have, during the design phase, is ruled out. However, with a closer look, it is observed that in general terms from the regulations, short tunnels have been stripped of all series of protections, "possibly" because of the supposed lower level of risk compared to long tunnels. However, the fact that these short tunnels do not have a tangible safety compliance scheme, puts them in a potentially high-risk classification, just like long tunnels. Therefore, they are vulnerable to the shortcomings that can be ensured from a holistic view of safety, whose vision is almost never fulfilled in a project.