Beyond A Tunnelvision Conference 2024

The fire performance of tunnel structures is typically specified through nominal fire resistance, where structural performance is evaluated considering a standardized heating curve for a prescribed number of minutes. Often the fire performance evaluation is further simplified by only considering limits to the temperature increase inside the concrete, hereby completely neglecting the redundancy in the structural system. Structural fire engineering calculations explicitly account for these redundancies in fire resistance evaluation, enabling optimized fire protection and potential cost reduction. There is however a second and more important benefit of structural fire engineering. Real fires do not only have a heating regime, such as those considered in the nominal fire resistance evaluations, but also a cooling phase. The cooling phase can cause significant changes in tunnel behavior, such as large permanent deformations, extensive cracking on the unexposed (cold) side, and in extreme cases, even structural collapse hours after the fire is extinguished. Structural fire engineering calculations allow to evaluate the tunnel’s fire performance during all phases of the fire. Thus, it is possible to design tunnels for burnout performance (meaning that the tunnel is designed to also survive the cooling phase), and even to design the tunnel to limit the post-fire damage and downtime. Ultimately, structural fire engineering calculations can help optimize fire protection strategies, balancing initial fire protection investments with potential damage costs, thereby reducing the lifetime cost of fire for tunnel structures.

In the latest COB tunnel deformation monitoring report for emerged tunnels various modern monitoring tools are described. For instance to monitor the movements of tunnel sections over the joint f.i. with a 3D joint sensor. In the past the monitoring was done with 3 potenial meters, each demanding a node to communicate with a gateway. The installation is demanding time and the dimensions of a cabinet to cover the meters is big. We will present data form various tunnel projects thus showing attendees the advantages of having all data in one screen. This new generation of sensors is very compact, easy to install and is not demanding any additional infrastructure or support. They do have their own battery and SIMCard and will work everywhere there is a mobile network available. The sensors also measures the temperature. Alarm settings can be given in and frequency can be changed in time if needed. Data can be imported by means of an API to any platform, tidal data as well as weather data can be integrated to the sensor data. Besides this we will shortly go into the deference between high frequency tiltmonitoring and static tilt monitoring. High frequency monitoring will show the real dynamic behaviour of any object.

An introduction to Beyond a tunnel vision 2024 by our hosts.

Fischer offers digital solutions for the building’s entire life cycle. Its range of products comprises global innovations in robotics and sensor technology, BIM services, the fischer FiXperience design software and digital services such as the fischer plug-finder app for selecting products. These solutions optimize the planning, construction, and operation of buildings. Creeping, shrinking, and setting construction materials - changes and deformations such as these present structural engineers with challenges when it comes to tunnels, wind turbines and bridges. It’s a good thing that our SensorAnchor provides a reliable, all-in-one solution offering maximum data transparency through the real-time transfer of preload and operating forces. This provides an early automatic warning for critical connections, allowing you to easily and conveniently monitor the data on the end device of your choice, resulting in minimal maintenance for structures of all sizes. During the workshop we will dive deeper into this technology.

VIA is currently in the second phase of developing a virtual tunnel laboratory for the development and testing of installations in realistic environments. Beside this virtual centre Norway has a Demo Tunnel Gandall. It is the industry’s arena for development, testing, demonstration and learning. The facility is Norway’s first full-scale demo tunnel and centre, filled with technology for the tunnels of the future. How did collaboration between government, industry and knowledge institutes succeed? Could this be of use for other tunnelowners?

Tunnels: a heritage to regenerate. In Italy, hundreds of tunnels, bridges and viaducts are needed to cross hills, valleys, and streams. Regenerating maintenance interventions on this important heritage and preventive maintenance of more recent assets have become urgent. No other country has so many. If we look at tunnels, Italy alone has half of all European tunnels, totalling 500 kilometres. However, this important heritage is ageing: most of the bridges, viaducts, tunnels and the motorway network itself were built between 1960 and 1980. In addition, the network has to cope with the stress caused by an average daily traffic of 40,000 vehicles per section (compared to 27,000 in France, for example), and with a particularly fragile territory and its hydrogeological instability. Suffice it to say that two thirds of the landslides in Europe occur in Italy and that this figure is likely to increase with the extreme events caused by climate change.It has become imperative to start a campaign of investigations on bridges, viaducts and tunnels considering the wear and tear caused by ageing, but also extreme weather events and the increasingly evident climate change, which affect road transport infrastructure. With support of the EU funds were allocated to start this campaign and Italy is now in the middle of this campaign. How far are they and what lessons have they learned so far?

The Beveren Tunnel renovation project is not just any renovation. It is a complex and large-scale project that poses significant challenges, especially in the field of Education, Training and Practice (ETP). But what makes ETP so crucial and challenging in these types of projects? The challenges of ETP in a tunnel renovation project such as the Beveren Tunnel are significant, but with the right approach they can be overcome. By investing in multidisciplinary consultation, extensive training, realistic training and capturing the lessons learned, we can ensure that everyone is as well prepared as possible for any challenge that arises. This not only makes the renovation safer and more efficient, but also contributes to the success and sustainability of the project.

The E-learning program 'how to renovate tunnels' aims to increase the basic knowledge level of employees in tunnel projects, improve understanding and thus prevent confusion. This allows tunnel professionals to be deployed faster and more efficiently and to collaborate better because they understand each other better and see each other's interests.

-

In Europe more and more tunnelowners program the renovation of their tunnels. Does this programming help tob e more attractive for contractors? Do smart solutions or innovations occur because of the repetitiveness and the larger scope? Or are the issues only more complex…. Major owners of tunnels discuss with each other about the benefits and challenges programming brings.

Alfons will share a new and inspiring perspective on the work of asset managers. With growing challenges and the continuous demand of society to keep critical infrastructure open at all times, the responsibility of tunnel managers increases. By presenting a wide range of learnings from international examples, he will provide practical ideas that will inspire the European asset management community to start looking for more international cooperation and smart learning.

The European Laboratory for Particle Physics (CERN) hosts the most powerful particle accelerator ever built, the Large Hadron Collider (LHC). To guarantee the safe running of the particle accelerators, the maintenance of CERN underground infrastructure plays an important role. Ageing and deterioration of tunnel defects are becoming more evident and inevitable. Detecting and monitoring cracks in tunnels are crucial for maintaining the structural integrity and safety of the infrastructure. However, access to most of the underground areas is regulated and granted only during specific periods of the year, for 1-2 months. Such limited time poses a great challenge to the visual inspection and field monitoring of the CERN infrastructure over tens of kilometres. The presentation will focus on CERN Tunnel Asset Management strategy and the implementation of smart monitoring technologies used to inspect and assess CERN large-scale infrastructure. This includes automated crack detection systems by using advanced robotics solutions and distributed fibre optic sensors, that can provide real/time data on structural changes, enhancing preventive maintenance activities.

With limited resources, understanding the lifecycle costs over the entire lifecycle of a tunnel is critical. Lifecycle costs (LCC) aggregates all costs incurred throughout the lifespan of an asset. The German DAUB has developed a model for calculating the LCC of a tunnel. While tailored for Germany, we believe there are significant opportunities to apply this model to your tunnel. Attend this presentation to gain insights into the model and explore opportunities for your tunnel.

Due to settlements, loads, and environmental impact, damage occurs in tunnel constructions by material degradation. How this degradation progresses cannot yet be accurately predicted. In collaboration with the Centre for Underground Construction the Technical University of Delft is developing the Fitbit for tunnels: a way to monitor the condition of tunnel structures. Starting by identifying and selecting the critical locations and deteriorations in a tunnel. Next, develop, select, test, and implement sensors capable of detecting relevant changes in material properties. Collect the data generated by these sensors and interpret it using Artificial Intelligence. This session will delve into the Fitbit for tunnels.'

Civil engineering is rapidly embracing digital innovations, and this trend extends to tunneling projects. In collaboration with UK Power Networks, we conducted a case study on automated tunnel inspections. Our approach involved robotic data collection and the utilization of machine learning-powered asset management tools. During the workshop, we will discuss the project’s main outcomes and lessons learnt. Additionally, we’ll provide an exhaustive cost-benefit analysis, considering factors such as enhanced safety, cost reduction, and improved repeatability.

The Austrian highway road operator ASFINAG has made a Expressway with more than 16km length in Vienna, including six tunnels within and the traffic control centre, self-sufficient by generating its energy. This energy is used for the normal daily consumption of the route, and the surplus is stored in large batteries. To transport and distribute the energy, ASFINAG has installed its own medium-voltage network. This allows energy to be generated, stored and used where and when needed. An central energy management system controls the energy flows and ensures monitoring. In a power outage around Vienna, the most critical systems on this layout can continue to operate for about ten hours. Learn more about the status, the methodology, the future of this project, and possibilities for your tunnel project.


Autostrade per l’Italia, with its engineering firms TECNE, has developed an approach to refurbish existing tunnels named Tunnel Renewal Strategy (“TRS”). TRS aims to achieve service life’s renovation through 8 different relining treatments. Over the last three years the design of the solutions has been developed and studied and key factors, leading to success or to the need for further improvements, have been identified. Beyond this, the method for selecting the right treatment among the solutions is driven by a multicriteria analysis including a supporting decision tool, based on asset management best practice, to account for others then technical aspects. Sound decision making is becoming part of the asset management strategy of the Organization, involving the Client and the Contractor in a continuous exchange of insights about budget limits, service life of the solutions and needed technologies to minimize the impact and keep serviceability of a very busy infrastructures.

HINFRA has developed a technology named ETLR (Extruded Tunnel Lining Regeneration), with the scope to build new linings for existing tunnels adopting an ultrafast horizontal slip-forming. The ETRL processing train is a machinery consisting of several modular units, each solving a specific function. The incremental industrialization of set of operations, typically the demolition, the surface preparation, and the new lining phases, combined with the performances of the special concrete, allow to target productivity rates far from the traditional methods in use in the industry. The engineered Fiber-Reinforced Concrete (FRC) is characterized by high early-age strength parameters, that allow a rapid slip-form at a predetermined time. A solid step into the technology implementation has consisted in the construction of a real scale extrusion facility, where the main components of the ETLR train are designed, produced, and tested. The solution was then transferred to pilot projects starting from 2023.

We present the monitoring system installed in the Rotterdam metro tunnel to safeguard the integrity of the immersed joints for the coming 10 years. In 2015, large-scale damage was detected in the immersion joints of the metro tunnel in Rotterdam. It was found that the Gina seals in the joints were pushing themselves inwards, causing damage both to the concrete tunnel walls and to the fixation of the support structures. An extensive renovation project was set up to repair the damage and to ensure that the tunnel joints are fit to last another 50 years. As part of this effort, an extensive sensing system was installed to permanently monitor the integrity of the joints. The system consists of a variety of sensors, measuring amongst others joint widths, shape and position of the Gina profiles, forces in the fixation brackets, water pressure and temperatures. Several systems were custom developed for application in this tunnel. In total, more than 1500 sensors are now continuously measuring the state of the tunnel joints. Data from all sensors is automatically transferred from the tunnel to a central cloud-based server and presented in near real-time via interactive dashboards in an online portal. Thresholds have been configured for the various measurements - when a measurement exceeds a threshold, an alarm is raised automatically, and a ticket is generated for follow-up action. The monitoring system provides invaluable input to the tunnel asset management team, not only about the current state of the tunnel, but also predicting future problems early, before they lead to damage. In this presentation, we describe the motivation for installing this unique monitoring system. We present the design of the various sub-systems, as well as the associated data processing pipeline, visualization dashboards and ticketing system for follow-up actions. We also present results from the first two years of measurements. Finally, we give some recommendations and good practices for future tunnel monitoring projects.

This workshop will discuss the growing appetite and opportunities for innovation in tunnel asset management. In particular computer vision based techniques enabling the automated capture of tunnel inspection imagery and data, advancements in data visualisation and dashboarding and the use of AI and machine learning for defect detection and inventorying. Benefits, blockers and lessons learnt from the development and deployment of innovative technology across tunnel projects in construction and under management across the world shall be discussed.

We will dive into the added value that can be created for the asset management of tunnels when attention is given to collection of immersion joint data. Which stakeholders should initiate data collection and who will benefit from this information. What aspects of tunnel sealing systems do we want to monitor during the tunnels lifetime to have an enhanced understanding on remaining design life? To answer these questions we have to create a clear overview of maintainance issues and uncertainties that come across in various tunnel projects. Practical examples will be given from various case studies encountered by Trelleborg.

Facing the complexities of tunnel longevity due to environmental impacts, thermal expansion and contraction, material wear, and aging, the precision in predicting how these stresses and movements affect tunnel structures is paramount. Tunnel joints are complex but vital components that accommodate tunnel movements while ensuring water tightness through a diverse and specific set of solutions and materials. This demands a specialized approach to investigate, analyze, engineer, and solve refurbishment challenges. This session introduces an innovative method that utilizes innovative diagnostic tools and dynamic modeling for residual lifetime determination of tunnel joints and integrates these insights into practical engineering solutions. We combine expert analysis with actionable refurbishment and modification strategies, crafted to meet the high standards of experienced tunnel engineers, asset owners, and asset managers. A significant part of this session will focus on helping participants recognize critical but often overlooked problems with underground tunnel joints. By demonstrating how to detect and address these issues before they lead to significant damage, we provide vital insights into maintaining the integrity of these essential components by addressing them as a system. By attending, you'll explore how to leverage these advanced techniques to enhance your existing knowledge and extend the operational life of critical infrastructure effectively. Join us to refine your expertise with the latest in tunnel assessment and intervention technologies.