PhD student Structural Mechanics: system identification and digital twins undergrou

Organisation/Company KU LEUVEN Department Structural Mechanics Research Field Engineering » Civil engineering Researcher Profile First Stage Researcher (R1) Final date to receive applications 15 Mar 2026 - 23:59 (UTC) Country Belgium Type of Contract Temporary Job Status Full-time Offer Starting Date 1 Oct 2026 Is the job funded through the EU Research Framework Programme? Not funded by a EU programme Reference Number BAP-2026-72 Is the Job related to staff position within a Research Infrastructure?

No

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.

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.

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…