We are looking for a PhD student holding a MSc degree in Civil or Computational Engineering, obtained not earlier than 2023, and having a solid background in one or more of the following subjects: structural dynamics, dynamic-soil structure interaction, computational mechanics, and structural health monitoring.
Transfer of knowledge towards countries that did not sign the non-proliferation treaty or of which the immaculate reputation regarding peaceful applications of radioactivity, scientific integrity or respect of economic rules is questioned in an international context, is conflicting with SCK CEN’s interests and values. Therefore, we will not consider candidatures from citizens originating from those countries.
This project investigates vibration-based methods for monitoring the structural health of deep underground tunnels throughout their lifetime. Structural Health Monitoring (SHM) based on dynamic system identification and digital twins has demonstrated significant advantages when applied to bridges, wind turbines, and high-rise buildings. Variations in dynamic characteristics - such as eigenfrequencies, mode shapes, and modal damping ratios - can indicate structural changes or damage. Along these lines, this project develops SHM methods for deep tunnels, with the HADES Underground Research Laboratory (URL) serving as the primary case study.
The monitoring strategy combines in situ vibration measurements with advanced numerical simulations. Deep underground structures are strongly influenced by complex dynamic soil–structure interactions. Vibration-based monitoring captures the coupled response of the tunnel and surrounding soil. Conventional techniques—such as visual inspection, strain gauges, and convergence measurements—often fail to detect distributed or deep-seated defects, require manual access, and offer limited spatial and temporal resolution. These methods also lack the sensitivity to detect early changes in global structural behavior. In contrast, wave-based techniques offer a complementary and more responsive alternative, though their application to tunnel–soil systems remains under-explored.
Coupled numerical models of the tunnel and surrounding soil will be developed, combining finite element with boundary element and perfectly matched layer formulations. These models will be used to compute modal characteristics, as well as dispersion and attenuation curves of guided waves along the tunnel. The models will simulate various environmental and damage scenarios, such as thermal loading and local changes in soil properties, and be used for parametric and sensitivity studies.
Forced and ambient vibration experiments will be conducted in the HADES URL to validate the models. Hammer impact tests will identify dispersion and attenuation curves and mode shapes, while long-term ambient monitoring will capture operational vibration patterns due to anthropogenic and natural excitation. The models will help interpret how different damage scenarios affect the ambient vibration signature. Both black-box and white-box damage identification algorithms will be assessed.
The resulting digital twin will serve as the foundation for a permanent SHM system for the galleries in the HADES URL. The developed methodology will also be applicable to future underground infrastructures such as geological disposal facilities, the Einstein Telescope and railway tunnels.
Within the frame of the research project “Dynamic system identification and digital twins for underground infrastructure monitoring”, the Structural Mechanics Section of the Department of Civil Engineering of KU Leuven, in collaboration with the Belgian Nuclear Research Centre (SCK CEN), has a vacancy for a PhD student. The project is co-funded by the Belgian Nuclear Research Centre (SCK CEN) and the Belgian National Agency for Radioactive Waste and enriched Fissile Material (ONDRAF/ NIRAS). The PhD student will work under supervision of prof. Stijn François and prof. Geert Degrande (Structural Mechanics Section, Department of Civil Engineering), as well as Arnaud Dizier and Jan Verstricht (SCK CEN). We offer an excellent and international research environment and have a lot of experience with supervising PhD students. Research in the Structural Mechanics Section (www.kuleuven.be/bwm) of the Department of Civil Engineering focuses on the static and dynamic analysis of structures and is structured along five research lines: vibration in the built environment, structural monitoring, building acoustics, computational structural engineering and human-induced vibration of civil engineering structures. The topic of this PhD thesis is situated within the themes of vibration in the built environment structural monitoring and computational structural engineering. The Department of Civil Engineering is nicely located in and near the Arenberg Castle on Campus Arenberg in Heverlee, one kilometre from Leuven’s city center. Founded in 1425, KU Leuven is currently the largest university in Belgium in terms of research funding and expenditure, and a charter member of LERU. KU Leuven conducts fundamental and applied research in all academic disciplines with a clear international orientation. KU Leuven is ranked as the 47th (globally) and 12th (European) university in the Times Higher Education ranking (2025) and as first European university in Reuters Top 100 of the world’s most innovative universities, for four years in a row. The HADES URL, located at a depth of 225 m in the Boom Clay Formation, was constructed by SCK CEN in the early 1980s beneath the SCK CEN site in Mol. In this URL, researchers and engineers have been studying the feasibility of safely disposing of high-level radioactive waste in deep geological formations. Over the past decades, numerous in situ experiments have been conducted in the HADES URL. These have made a significant contribution to ONDRAF/NIRAS’ research, development, and demonstration efforts, demonstrating that disposal in Boom Clay can offer a safe solution for the long-term management of high-level and/or long-lived radioactive waste. Moreover, the construction of the HADES URL itself demonstrates that shafts and galleries can be constructed in clay at that depth.
Interested candidates should be motivated to complete a PhD within four years, starting as soon as possible (preferably no later than 1 October 2026).
The PhD student will enroll at KU Leuven and be affiliated part-time to KU Leuven and to SCK CEN.
We offer a competitive PhD grant of about 2485 EUR per month net, depending on your marital status.
More information on becoming a PhD student at KU Leuven and living in Leuven can be found at www.kuleuven.be/phd, set.kuleuven.be/phd (Leuven Arenberg Doctoral School) and www.kuleuven.be. Depending on their background (MSc diploma, research experience), students may first need to pass a pre-doctoral test, e.g. selected courses (12 ECTS) and research work with presentation (3 ECTS), prior to being allowed to the PhD program.