Energy quay walls (EQWs) represent an emerging class of energy geostructures that combine geothermal heat exchange with retaining-wall functions along waterways. While their thermal performance has been investigated in several recent studies, their thermo-mechanical (TM) behaviour remains less well documented, particularly under realistic long-term operating conditions. This paper presents a thermo-mechanical analysis of a full-scale EQW installed along the Delftse Schie canal (The Netherlands), combining field temperature and displacement monitoring with calibrated finite-element modelling. A two-dimensional plane-strain model is developed to reconstruct geostatic and thermal initial conditions, simulate short-term geothermal activation phases, and assess the long-term TM response under repeated seasonal operation. Model predictions show that TM-induced wall deformations are small. Short-term TM displacements are on the order of a few tenths of a millimetre, while long-term seasonal activation produces cyclic, predominantly reversible displacements in the millimetric range. No accumulation of plastic strain is predicted over the analysed geothermal operating period. The simulated deformation patterns reflect the combined influence of non-uniform temperature fields, stratigraphic stiffness contrasts, and thermo-elastic deformation of the steel sheet pile, rather than simple uniform thermal expansion or contraction. Overall, the results indicate that thermo-mechanical effects in the investigated EQW are modest and can be reasonably captured by calibrated numerical modelling evaluated against field observations. The study provides a reference framework for incorporating TM considerations into the design and serviceability assessment of EQWs and similar energy geostructures.
The mechanical behaviour of the interface significantly influences the interaction between soil and structure under shear deformation, as the transfer of forces primarily occurs through it. In general, interface modelling is divided into normal (pressure transfer or gap opening) and shear directions. Existing interface model implementations using the soil’s material model in the far-field focus on a realistic representation of the shear behaviour. They typically assume a free-volume change in the normal direction, thus allowing only the modelling of boundary conditions with a constant normal stress acting on the interface. As a result, the effects of jamming and unjamming due to volumetric soil behaviour within the interface — arising under deviating boundary conditions — are neglected. Depending on the soil’s initial state, this can lead to over- or underestimation in real geotechnical scenarios involving soil–structure interaction (SSI) under shear, i.e., the load-bearing capacity of piles, anchors, and soil nails. To address this shortcoming, we present an extended approach for modelling the soil–structure interface. The proposed method enables the determination of the normal stress acting on the interface from strains induced by both the adjacent soil and the soil within the interface zone. This allows the normal stress to be evaluated while accounting for the constrained volumetric deformation of the soil within the shear zone and the stiffness of the surrounding soil. Accordingly, our approach accounts for jamming and unjamming effects using the constitutive equations of the far-field soil.To validate the new model’s performance, we compare it with experimental results from interface shear tests reported in the literature using a hypoplastic constitutive model. The qualitative agreement between simulations and experimental data demonstrates that the observed effects in the interface shear zone can be realistically captured by the proposed model, thereby providing a useful numerical tool for SSI analyses.
