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Design Fires in Road Tunnels (2011)

Chapter: Appendix D - Tunnel Safety Projects Additional Descriptions

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Suggested Citation:"Appendix D - Tunnel Safety Projects Additional Descriptions." National Academies of Sciences, Engineering, and Medicine. 2011. Design Fires in Road Tunnels. Washington, DC: The National Academies Press. doi: 10.17226/14562.
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Suggested Citation:"Appendix D - Tunnel Safety Projects Additional Descriptions." National Academies of Sciences, Engineering, and Medicine. 2011. Design Fires in Road Tunnels. Washington, DC: The National Academies Press. doi: 10.17226/14562.
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Suggested Citation:"Appendix D - Tunnel Safety Projects Additional Descriptions." National Academies of Sciences, Engineering, and Medicine. 2011. Design Fires in Road Tunnels. Washington, DC: The National Academies Press. doi: 10.17226/14562.
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Page 153
Suggested Citation:"Appendix D - Tunnel Safety Projects Additional Descriptions." National Academies of Sciences, Engineering, and Medicine. 2011. Design Fires in Road Tunnels. Washington, DC: The National Academies Press. doi: 10.17226/14562.
×
Page 153
Page 154
Suggested Citation:"Appendix D - Tunnel Safety Projects Additional Descriptions." National Academies of Sciences, Engineering, and Medicine. 2011. Design Fires in Road Tunnels. Washington, DC: The National Academies Press. doi: 10.17226/14562.
×
Page 154
Page 155
Suggested Citation:"Appendix D - Tunnel Safety Projects Additional Descriptions." National Academies of Sciences, Engineering, and Medicine. 2011. Design Fires in Road Tunnels. Washington, DC: The National Academies Press. doi: 10.17226/14562.
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Page 155

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151 D.2.4 INTERNATIONAL TECHNOLOGY SCANNING PROGRAM (2) The nine initiatives and practices listed below relate to human factors, planning, design, and incident and asset management. 1. Develop Universal, Consistent, and More Effective Visual, Audible, and Tactile Signs for Escape Routes. The scan team noted that the signs Europeans use to indicate emergency escape routes are consistent and uniform from country to country. Emergency escape routes are indicated by a sign showing a white-colored running figure on a green background. Other signs that indicate the direction (and distance in meters) to the nearest emergency exit also have the white figure on a green background, as used in European buildings and airports. All SOS stations in the tunnels were identified by the color orange. This widespread uniformity pro- motes understanding by all people and helps assure that in the event of an emergency, any confusion related to the location of the emergency exit will be min- imized. In addition, the team learned that combining the use of sound that emanates from the sign, such as a sound alternating with a simple verbal message (e.g., “Exit Here”) with visual (and, where possible, tactile) cues, makes the sign much more effective. The U.S. tunnel engineering community relies on National Fire Protection Association (NFPA) 130, Standard for Fixed Guideway Transit and Passenger Rail Systems, and NFPA 502, Standard for Road Tun- nels, Bridges, and Other Limited Access Highways, for fire protection and fire life safety design standards. These standards need to incorporate the most current technology and results of recent human response studies on identification and design of escape portals, escape routes, and cross passages. 2. Develop AASHTO Guidelines for Existing and New Tunnels Single-source guidelines for planning, design, con- struction, maintenance, and inspection of roads and bridges have been in place for many years. NFPA has developed standards for safety in highway tunnels and passenger rail tunnels. The American Public Trans- portation Association (APTA) has general safety stan- dards and guidelines for passenger rail operations and maintenance that incorporates some of the NFPA standards by reference. However, AASHTO does not have standards or guidelines specifically for highway or passenger and freight rail tunnels. Recently, the AASHTO Subcommittee on Bridges and Structures created a new committee, the Technical Committee on Tunnels (T-20), to help address this problem. T-20 takes the lead in developing AASHTO standards and guidelines for existing and new tunnels, working with NFPA, APTA, FHWA, and the appropriate TRB com- mittees on standards and guidelines for highway and passenger and freight rail tunnels. Tunnel safety mea- sures such as the Mont Blanc Tunnel emergency pull- out area and variable message sign showing maximum speed limit and required vehicle spacing, as well as refuge room requirements require considerations. 3. Conduct Research and Develop Guidelines on Tunnel Emergency Management that Includes Human Factors Tunnel design solutions may not anticipate human behavior. Consistently predicting the way people will behave in an incident is difficult. During emergency situations, human behavior is even harder to predict as the stress of the situation replaces intellect with curios- ity, fear, or even panic. During a tunnel emergency, people often must be their own first rescuers and must react correctly within a few minutes to survive. Tunnel emergency management scenarios and procedures must take human behavior into account to be fully effective in saving lives. The European experience in human factor design provides a good basis for the United States to discover and include more effective measures for tunnel planning, design, and emergency response. 4. Develop Education for Motorist Response to Tunnel Incidents During an emergency situation, most people do not immediately know what to do to save themselves and others. Motorists are their own first rescuers and Euro- pean studies indicate that self-rescue may be the best first response for a tunnel incident. For this to be an effective strategy, it is important to educate the public about the importance of reacting quickly and correctly to a tunnel incident, such as a fire. 5. Evaluate Effectiveness of Automatic Incident Detec- tion Systems and Intelligent Video for Tunnels The scan team learned of sophisticated software that, using a computer system interfacing with ordinary APPENDIX D Tunnel Safety Projects Additional Description

152 video surveillance cameras, automatically detects tracks and records incidents. As it does so, it signals the oper- ator to observe the event in question and allows the operator the opportunity to take the appropriate action. This concept can also be applied to detect other activi- ties and incidents in areas besides tunnels, including ter- rorist activities, crashes, vandalism and other crimes, fires, and vehicle breakdowns. 6. Develop Tunnel Facility Design Criteria to Promote Optimal Driver Performance and Response to Incidents The Europeans found that innovative tunnel design that includes improved geometry or more pleasing visual appearance will enhance driver safety, perfor- mance, and traffic operation. For example, the full-size model of one section of the twin roadway tube for the A-86 motorway in Paris demonstrates the effectiveness of good lighting and painting to improve motorist safety. It is a particularly important consideration for a tunnel roadway section designed with limited headroom. 7. Investigate One-Button Systems to Initiate Emergency Response and Automated Sensor Systems to Deter- mine Response The European scan revealed that one of the most important considerations in responding to an incident is to take action immediately. For this to be effective, the operator must initiate several actions simultane- ously. An example of how this immediate action is accomplished is the “press one button” solution that initiates several critical actions without giving the operator the chance to omit an important step or per- form an action out of order. From the Mont Blanc Tunnel operations center control panel, operators can initiate several actions by moving a yellow line over the area where a fire incident is indicated on a com- puter screen. This “one-button” action reduces the need for time-consuming emergency decisions about ventilation control and operational procedures. The Europeans observed that tunnel operations per- sonnel have difficulty keeping up with events like tun- nel fires. They believe that an automatic system using devices like opacity sensors can help determine the correct response. A closed-loop data collection and analysis system that takes atmospheric conditions, tun- nel air speed, and smoke density into account may best control fans and vents. 8. Use Risk-Management Approach to Tunnel Safety Inspection and Maintenance The scan team learned that some organizations use a risk-based schedule for safety inspection and maintenance. Through knowledge of the systems and the structure gained from intelligent monitoring and analysis of the collected data, the owner can use a risk- based approach to schedule the time and frequency of inspections and establish priorities. It makes more sense to inspect less critical or more durable portions of the system on a less frequent basis and, instead, con- centrate inspection efforts on the more critical or more fragile components. A risk-based assessment of the condition of facilities also can be used to make optimal decisions on the scope and timing of facility mainte- nance or rehabilitation. This method offers a statistical process to manage the tunnel assets. 9. Implement Light-Emitting Diode Lighting for Safe Vehicle Distance and Edge Delineation in Tunnels The scan team noted that in several European tun- nels, light-emitting diode (LED) lights were installed along the edge of the tunnel at regular intervals of approximately 10 to 20 meters (m), or 33 to 66 feet (ft), to clearly identify the edge of the roadway. These lights were either white or a highly visible yellow color. In some tunnels, there were blue lights at 150 m (490 ft) intervals spaced among these edge-delineation lights. Motorists are instructed through formal (for truck and bus drivers) and informal driver education to keep a safe distance between them and the vehicle in front, and that distance is indicated by the spacing of the blue lights. This visual cue is more reliable than asking motorists to establish distance between vehicles using speed based guidelines, such as maintaining one car length spacing for every 10 miles per hour (16 kilometers per hour) of speed. The LED markers are also less susceptible to loss of visibility because of road grime and smoke during a tunnel fire. D.2.5 UPTUN (8) WP1. This work package assesses monitoring and detection systems installed at present, assessed if improvements to those systems could be made, evaluate new methods and tech- niques for determining incidents and fires inside and outside tunnels. In order to ensure that the ultimate results of UPTUN are achieved it was necessary to make a detailed database of all road tunnels in Europe, detailing the type of tunnels in each country, what types of detection systems are in place, whether any suppression systems are installed, and details of recent incidents. This database was used to analyze these recent incidents and to assess if tunnels that have better mon- itoring and detection systems achieved a quicker response to an incident, which would reduce the impact of an incident and minimize the economic impact in the surrounding areas. WP1 Technical tasks: 1.1 Categorization and listing of European tunnels. 1.2 Causes and prevention of accidents and fire.

153 1.3 Existing detection and monitoring systems. 1.4 Exploration of alternative or new technology for detec- tion of moving fires, detection of fires outside tunnels, detection of the migration of fires. 1.5 Implementation of proposed solutions and prototypes. WP1 Objectives: • To categorize European tunnels. • To identify probabilities of incidents potentially leading to fires and propose, investigate and promote methods to reduce these. • To list potential suitable existing detection and moni- toring techniques and to investigate reliability of exist- ing systems. • To develop innovative measures to detect the fire load and growth. Small-scale tests were performed to evaluate the new sys- tems with regard to reliability, accuracy, fire resistance, and so forth. WP2. (78) WP 2 aims primarily at developing cost-efficient mitigation measures when a fire occurs in a tunnel. The focus of the work package is therefore an existing and innovative mitigating system. In support of this objective, it aims at improving the necessary evaluation tools and at providing innovative new tools where appropriate. Specifically envis- aged tools are the mathematical models and the appropriate design scenarios that enable the prediction of hazard condi- tions. The appropriate design shall be based on statistical data and laboratory-scale tests. By providing better knowledge about the fire and explosion hazards involved, design fire sce- narios and acceptance criteria were to be developed. WP2 Technical tasks: 2.1 Development of realistic design scenarios 2.2 Define acceptance criteria (79). 2.3 Evaluation of existing tunnels and current technology (80). 2.4 Develop new innovative technologies (81). 2.5 Engineering guidance and implementation (82, 83). WP2 Objectives: • To provide design fires. Design fires will be used to mea- sure the efficiency of all mitigation systems. Acceptance criteria for fire effluence in the tunnel shall be suggested to provide a necessary level of safety to be achieved by mitigation technologies. • Establish knowledge about the performance of current technologies and to provide a path for development and verification for innovative technologies. • To improve and to verify the efficiency of innovative fire mitigation systems in tunnels, both as stand alone systems and in combinations with other systems. Focus shall be given to cost-efficiency. • Identify parameters affecting the effect of mitigation and to provide guidance on how to design a reliable mitiga- tion system and to predict the resulting achievements. • Results of the study were summarized in the paper by Haukur Ingason of SP Swedish National Testing and Research Institute “DESIGN FIRES IN TUNNELS” referenced and further discussed in this report (28). WP3. The main objective of WP3 was to find, develop, evalu- ate, and promote new methods and means to remove, neutral- ize or correctly assess all factors that contribute to a negative human response in incidents (larger accidents always resulted from smaller incidents) and accidents (resulting if no ade- quate action is taken). WP3 Technical tasks: 3.1 Review of state of the art and interrelation with other projects. 3.2 Response of the end-user. 3.3 Tunnel operator. 3.4 Emergency response teams. WP3 Objectives: • Knowledge will be collected on the design and safety measures in current European tunnels. • This task focuses on how information is presented, how long it takes before tunnel users actually under- stand the situation (depending on specific scenario and the information provided), and how they choose their escape route. • This task will focus on an analysis of the task of the operator: how operators gain information, what makes them miss some incidents, how the operators come to a decision, what way can they be supported, how the operators handle the occurrence of several incidents within a short period of time, and how the operators communicate with the emergency rescue teams. It seems important to discuss some results of this work group for the benefits of agencies and operators. Simulta- neous management of the problem is required in order to guarantee effective and on-time intervention of operators. The response teams get their information from the tunnel operator (or from the individual tunnel users) and have to form an idea of the seriousness of the incident, the actions they have to take, the number of people that have to be involved, followed by having to instruct their team mem- bers to work together. Furthermore, the tunnel operators may also help the emergency response teams by providing proper information. The tunnel operator has an important role to react to a tunnel incident in a timely manner. The operator needs to stand-by in order to detect any incidents happening, to decide what the proper action to take is, and needs to provide other people with information (road users, emergency services, other operators, and so forth). The role of the operator is extremely important (overview of the situation, possibilities to commu- nicate to several services, and so forth).

154 In the UPTUN project, an analysis was done of operator tasks and bottlenecks based on literature reviews, a Dutch tun- nel safety review, and operators interviews. The tasks identified were: • Monitoring the traffic flow and situation in the tunnel (and vicinity) using cameras, sensor readings, and com- munication equipment. Constant vigilance was required. • Preparation for effect reduction: education, training, exercises. • Fast and correct detection of any event or disturbance likely to escalate into an incident. • Closing the tunnel; switching equipment to “emergency mode” (lights, ventilation, speed limits, escape doors, and so forth). • Alerting other operators (where applicable), rescue ser- vices, and tunnel users (instructing them for escape if necessary). • Communicating with tunnel users to help them escape and to help them assist others or correct the situation (such as, extinguishing a small fire). • From the control room, assisting the rescue services in their rescue operation. • Evaluating and registering the incident. The main factors that have a substantial effect on task per- formance and mental effort of the operator are: 1. Percentage time occupied: the percentage of available time that the operator is occupied with his or her tasks. The higher this percentage is, the higher the cognitive load. 2. Level of information processing: relates to the com- plexity of tasks. 3. Number of task-set switches: refers to the number of switches the operator has to make between different task-sets. The more switches, the higher the cognitive load. The operator overload can occur when the operator does not have enough time to finish the tasks, the operator tasks are too complicated, or the operator has to perform too many tasks at the same time (or a combination of any of these elements). An underload, just as overload, may lead to sub- optimal performance. Ideally, the task load matches the oper- ator’s mental capacity in a certain task setting. Other identified bottlenecks (although this list does not include all bottlenecks identified) were: • Vigilance problems during long periods of normal oper- ation (related to underload). • Unclear allocation of responsibilities and authority to personnel. • Insufficient skills due to lack of practice exercises, espe- cially with the rescue services. • Overdue, incorrect, or incomplete detection of incident due to the combination of suboptimal cognitive load and suboptimal detection of risk factors in tunnel. • Too many incoming signals, not all of which are rele- vant at this time (related to overload). • Absence of or insufficient coordinated procedures between operators and rescue services. • Absence of adequate incident evaluating and registra- tion procedures. • Mistake in incident is not evaluated or registered due to fear for career consequences. After the tasks and bottlenecks were identified, the next step was to find solutions for the most important bottlenecks and designing an improvement strategy. Using a prioritized list of bottlenecks and general methods for influencing opera- tor behavior generates possible solutions for the most impor- tant bottlenecks. Possible solutions can be found in terms of: • Recruitment (assess the proper criteria). • Training and exercise (to improve skills, but also to test the affectivity of procedures). • Personnel and organization (number of people present, working method with time schedules and organiza- tional culture). • Task support (such as procedures and guidelines). • Control room and interface design (technical tools, such as one button to indicate a major accident, good tools to instruct the tunnel users). WP4. The objectives are: • To optimize the thermal and structural behavior of all tun- nel 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 phase conditions: from ignition, through growth to the fully developed stage and the decay period. • To achieve a robust working/functioning complete sys- tem, 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 recommenda- tions for optimal tunnel systems. WP4 Technical tasks: 4.1 Structural elements functional performance, and load bearing capacity. 4.2 Improving components functional capacity. 4.3 Innovative damage assessment and repair and recovery and retrofitting. 4.4 Proposal of innovative solutions. 4.5 Safety levels criteria evaluation/engineering guidance and implementation. WP4 Objectives: • It is necessary to achieve better understanding and gain more insight in structural performance of concrete load- bearing elements under fire emergency conditions

155 • To develop new mitigating measures. • To avoid or limit structural damage to an acceptable level. • To provide fast repair methods. By means of numerical analyses and laboratory fire tests, data are established for all individual elements regarding its resistance and functionality as a function of its exposure time. These data help to point out possible improvements to currently available elements and to make recommendations for designing new ones. The different element with the best characteristics is identified and, if appropriate, proposed for use in upgrading tunnels. Therefore, it is essential 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 devel- opment of innovative FAST and ACCURATE damage assess- ment techniques. For tunnels where current system design is not suitable, alternative innovative solutions shall be sug- gested. Alternative optimized configurations and advanced technological engineering solutions shall be studied and ver- ified. Indications on how to achieve reductions and/or elimi- nation of explosive spalling were given. WP5. This task encapsulates the essence of the UPTUN project; namely, the evaluation and upgrading of the safety level of existing tunnels consistent with the safety levels established in this project as a whole. In that respect, this work package brings together all the various strands from the other work packages and, therefore, inevitably requires input from and collaboration with all the partners of this major project. WP5 Technical tasks: 5.1 Identifying safety features. 5.2 Setting criteria for evaluating safety levels and systems failure. 5.3 Holistic evaluation and upgrading of existing tunnels safety. 5.4 Example: Upgrading of an existing tunnel. 5.5 Financial, socio-economic, macroeconomic, and envi- ronmental evaluation of upgrading tunnels to improve fire safety. WP5 Objectives: • To ensure that the safety features are clearly identified in a rational manner. • To ensure that the evaluation criteria are clearly defined in a rational manner taking into consideration the inter- action between the different safety features. • To develop a procedure called “UPGRADE” for eval- uating and upgrading the safety level of a tunnel as a whole and to present the output in terms of risk profiles for both people and the infrastructure. An assessment of fire risk profiles for a tunnel before and after upgrad- ing will then allow the socio-economic impact to be evaluated. • To demonstrate the practical utility of the evaluating and upgrading procedure by applying it to an existing tunnel. • To demonstrate the cost-effectiveness of the UPTUN project and assess its wider socio-economic impact. WP6. Objectives: • Demonstrate experimentally the effectiveness of the innovative fire safety features in combination. • Demonstrate, with before and after tests, that the in- novative upgrading measures proposed in this project provide major improvements in fire safety when compared with the existing tunnels situation without upgrading. • Provide feedback to work packages 1 to 4 in terms of the interaction of their individual features with the fea- tures developed in other work packages. • Validate the theoretical model developed in work package 5. • Make recommendations for upgrading based on actual testing. WP6 Technical tasks: 6.1 Framework for the demonstrations 6.2 Demonstration before upgrading 6.3 Demonstration after upgrading 6.4 Analysis of results and validation of theoretical model WP6 Objectives: • To optimally design full-scale tests that show interaction and validate the models developed in the previous work package. • To set a reference for identifying the positive effect of the innovative measures or innovative combination of mea- sures by determining the safety level of non-upgraded tunnel(s). • To investigate the innovative measures in realistic con- figurations and combinations to determine their actual beneficial effect. To gather validation information for the models developed in the other work packages. • To provide validation information for the theoretical models. To make recommendations for large scale data gathering and analyses. To provide adequate promo- tional and educational material. Furthermore, since not all aspects can be foreseen from the start of the project, nor can all problems be solved within UPTUN, strong links have been established with existing relevant research projects on the national and international level, such as the European projects DARTS, FIT, and SafeT. WP 7 Promotion, dissemination, education/training, and socio-economic impact (WPL STUVA; D)

156 D.2.6 FIT (8) Technical Report Part 1, Design Fire Scenarios (76), de- scribes recommendations on design fire scenarios for road, rail, and metro tunnels. Design fires are to cover different relevant scenarios, such as design fires in regard to the evacuation of people and to ventilation purposes, as well as in regard to the structural loads, which are presented and recommended. The report collects data from different coun- tries, including Germany, France, Italy, and the U.K., as well as international organizations, such as PIARC, ITA, and UPTUN. It also incorporates from the experiences in individual tunnels, including Mont Blanc, Tauern, Nihon- zaka, Caldecott, and Pfänder. The report includes basic prin- ciples of design fires, tunnel fire statistics, and impacts of fires and smoke in tunnels on people, equipment and struc- ture. The data are analyzed and different sets of data are compared to ascertain the degree of confidence attributed to the information. In Technical Report Part 2, Fire Safe Design, a compilation of relevant guidelines, regulations, standards, or current best practices from European member states (and major tunneling countries, like Japan) are given. The analysis is focused on all fire safety elements regarding tunnels and is classified accord- ing to the transport nature: road, rail, and metro. The three sections in the report present the collected guidelines and regulations, their analytical abstract, and table of contents. About 50 safety measures are presented and compared related to structural measures (19), safety equipment (36), and struc- ture and equipment with response to fire (3). For each type of measure the impact on safety is presented with a synthesis and a detailed comparison of the comprehensive list of safety measures. The occurrence of a fire in a tunnel provokes a need for responses from tunnel users, the operators, and the emergency services personnel. Technical Report Part 3, Fire Response Management, presents the best practices to ensure a high level of safety.

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TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 415: Design Fires in Road Tunnels information on the state of the practice of design fires in road tunnels, focusing on tunnel fire dynamics and the means of fire management for design guidance.

Note: On September 20, 2011, the following errata was released related to NCHRP Synthesis 415. The electronic version of the publicaiton was changed to reflect the corrections.

On pages 106 and 107, an incorrect reference was cited. In the final paragraph on page 106, the last sentence should read: One study came to the conclusion that, although some minimum water application rates would achieve a certain objective, a marginally higher rate would not necessarily improve the situation (79). The figure caption for Figure 35 at the bottom of page 107 should read: FIGURE 35 NFPA 13, NFPA 15, and other International Water Application Rates (79).

The added reference is as follows:

79. Harris, K., “Water Application Rates for Fixed Fire Fighting Systems in Road Tunnels,” Proceedings from the Fourth International Symposium on Tunnel Safety and Security, A. Lönnermark and H. Ingason, Eds., Frankfurt am Main, Germany, Mar. 17–19, 2010.

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