Dr Andrea Franza is Assistant Professor of Geotechnical Engineering. His research bridges geotechnical and structural engineering. For this, he employs analytical and numerical modelling along with reduced-scale physical testing and field monitoring. He holds a PhD in Civil Engineering from the University of Nottingham (UK) and had postdoctoral experience at the Centre for Smart Infrastructure and Construction at the University of Cambridge and the Universidad Politécnica de Madrid.
Currently, he is currently Associate Editor for the journal Tunnelling and Underground Space Technology. He represents the Danish Geotechnical Society as a nominated member of ISSMGE Technical Committees TC204 (Underground Construction) and TC308 (Energy Geotechnics).
EDUCATION
Civil Engineering, PhD, University of Nottingham
2013 → 2016
Civil Engineering, Msc (cum laude), Marche Polytechnic University
2010 → 2013
Civil Engineering, BSc (cum laude), Marche Polytechnic University
2007 → 2010
RESEARCH, TEACHING, or OTHER INTERESTS
Civil and Structural Engineering
72
Scopus Publications
1692
Scholar Citations
22
Scholar h-index
41
Scholar i10-index
Scopus Publications
Underground energy storage using man-made CO2 hydrate geo-capsules Omer Lev-Yehudi, Qian Ouyang, Andrea Franza, Nicolas von Solms, Assaf Klar Tunnelling and Underground Space Technology, 2026 The increasing reliance on renewable energy sources presents challenges due to their intermittent and variable nature, necessitating efficient energy storage solutions. Underground Mechanical Energy Storage (UMES) has emerged as a promising approach, utilizing subsurface reservoirs to store pressurized fluids. However, the deployment of UMES systems is constrained by the availability of suitable natural subsurface formations. This study explores a novel concept of forming impermeable CO<sub>2</sub> hydrate geo-capsules within porous soil deposits at depths of 50–400 m for fluid-based UMES applications, leveraging gas hydrate-bearing sediments’ unique properties of extremely low permeability and increased stiffness. An analytical mechanical model is developed to describe the overall capsule response to energy storage, incorporating a spherical multi-layered elasto-plastic solution for internal fluid injection. The analytical model is validated through numerical simulations, which are also used to extend the investigation to varying lateral earth pressure conditions (k<sub>0</sub>≠1). A solution space mapping is then performed to evaluate the influence of key geometrical and stiffness parameters on the mechanical response of hydrate geo-capsules, followed by an assessment of pressure retention over time. The framework is further extended to estimate the energy storage capacity of a single or multiple capsules, considering a hybrid Pumped-Hydro Compressed Gas Energy Storage (PH-CGES) configuration. This study provides a first-step assessment of hydrate-based UMES feasibility and establishes a baseline for future investigations.
Experimental study of sugar-induced sand cementation in dry conditions Gianmario Sorrentino, Andrea Franza Geomechanics for Energy and the Environment, 2025 This paper presents an experimental study of sugar as a low-viscosity cementing agent for sand in dry laboratory conditions. Sand was mixed with aqueous sugar solutions of varying concentrations (15%–40% by mass) and oven-cured at different temperatures. Unconfined compressive strength (UCS) tests showed that strength increased with sugar concentration, with UCS values reaching up to 6 MPa —comparable to or exceeding those achieved with conventional bio-cementation methods. Optimal curing occurred at 105 °C, balancing rapid hardening and peak strength, while excessive heating at 170 °C reduced strength due to sugar caramelisation. Nevertheless, all conditions yielded mean UCS values above 1 MPa, demonstrating the method’s reliability. Scanning electron microscopy (SEM) was used to observe the interaction between sugar and sand particles, revealing a substantial sugar coating bonding the grains. These findings reveal some of the fundamental mechanisms of sugar-induced cementation. Finally, research pathways and current shortcomings for field applications are discussed. • Sugar-based cementation of sand investigated under different curing conditions in dry soils. • UCS exceeded: 6 MPa at 40% sugar concentration under optimal curing; 1 MPa across all testes. • Stress–strain curves were nearly linear up to peak, followed by a softening response. • SEM imaging confirmed sugar crystallisation at grain contacts, forming interparticle bonding structures.
Synthesis of CO2 hydrate capsules in partially water-saturated sediment as vessels for underground mechanical energy storage: Promoting effect of tetrahydrofuran and cyclopentane Qian Ouyang, Omer Lev-Yehudi, Jyoti Shanker Pandey, Andrea Franza, Irene Rocchi, Assaf Klar, Nicolas von Solms Fluid Phase Equilibria, 2025 • Capsules of CO 2 hydrates in confined sand sediments are synthesized. • Three synthesis stages exist during CO 2 gas injection in water and promoters. • CO 2 injectivity during the synthesis of CO 2 hydrate capsules is evaluated. • Shut-in periods induce hydrate blockage, hindering CO 2 gas injection. • Injection of THF or CP increased CO 2 density by 74.5% or 128.3% in confined sand sediments. The intermittency of renewable energy sources and the increase in renewable energy shares require energy storage capability to sustain the green transition. One promising solution for underground energy storage is the use of subsurface CO 2 hydrate capsules, which act as impermeable vessels that store compressed fluids and discharge them upon need. However, as part of the proof-of-concept study of this technology, the feasibility of constructing such vessels, e.g. CO 2 hydrate capsules, has yet to be demonstrated. This work employed CO 2 gas injection assisted by chemical solution into partially water-saturated sand sediments to synthesize CO 2 hydrate capsules. The concentrations of chemical solutions (THF, CP and DIOX) were screened out in the gas/liquid/sand system in terms of kinetic promotion, using a rocking cell. Separately, experiments were carried out with a new high-pressure chamber set-up that quantified the effects of water saturation and chemical promoters on the efficiencies of CO 2 hydrate synthesis in confined partially water-saturated sand. Results on the gas/liquid/sand system showed that 0.025 water/CP weight ratio CP solution and 1.3mol% THF solution induced the largest pressure drops of 18.4 ± 0.2 bar and 16.7 ± 0.1 bar, respectively, indicating the most promoted CO 2 hydrate formation kinetics. Results with the pressure chamber showed three stages during slow CO 2 gas injection: (1) initial pressure “build-up stage”; subsequent (2) CO 2 gas “uptake stage”; and (3) CO 2 injection “closing stage”. CO 2 hydrate formation kinetics of CO 2 hydrate retention percentage (S CO2 ) and CO 2 hydrate density (ρ CO2 ) were directly proportional to the initial water saturation (6.0–76.7%). Injection of THF or CP solutions increased S CO2 by 16.5% or 18.5%, and ρ CO2 by 74.5% or 128.3% compared to injection of water. The best performances were obtained at a fluid pressure of 27.0 bar, with a 0.025 water/CP solution-assisting CO 2 gas injection, in sediment with an initial water saturation of 32.6% and porosity of 44.6%, giving rise to S CO2 of 67.2% and ρ CO2 of 80.6%. These findings demonstrated that the injection of THF or CP solution with CO 2 gas facilitated the possibility of the formation and stabilization of subsurface CO 2 hydrate capsules.
Load transfer mechanisms for capped and uncapped non-displacement piles above tunnels: a centrifuge modelling study Chuanjin Tang, Andrea Franza, Jingmin Xu, Alec M. Marshall Geotechnique, 2025 This paper presents results from geotechnical centrifuge tests of tunnelling in dry dense sand beneath loaded non-displacement piles, focusing on the effect of a pile cap (representative also of a raft or grade beam) in contact with the soil surface on load transfer mechanisms. Experiments included loading tests to ascertain the foundation capacity and load–displacement response in the presence/absence of an underlying model tunnel. Individual ‘reference’ pile response is compared for cases with and without a pile cap, including pile displacements and load distributions between the head, shaft and base; the case of ‘friction’ piles with a compressible base is also considered. Results show that uncapped piles with relatively large service loads experience ‘geotechnical failure’ (i.e. large settlements or a significant increase in settlement rate with tunnel volume loss) in order to mobilise base or shaft resistance. Pile caps are shown to reduce settlements and prevent geotechnical failure of both reference and friction piles; they also improve the post-tunnelling foundation performance under loading. The paper provides evidence to enable engineers to consider the beneficial role of shallow elements in contact with the surface on the performance of pile foundations both during and subsequent to tunnelling.
Tunnelling-induced wall damage: An appraisal of elastoplastic constitutive models for masonry Yalin Yu, Andrea Franza, Bahman Ghiassi, Luis Canhoto Neves, Alec M. Marshall Tunnelling and Underground Space Technology, 2025 This paper investigates the role of masonry elastoplastic constitutive models on tunnelling-induced damage in buildings. A two-stage analysis method (TSAM) is adopted, incorporating input greenfield displacements, 3D masonry walls, and an elastic model for the soil. The paper focuses on four masonry constitutive models that can be readily adopted for routine analysis in industry. Comparison of in-plane yield surfaces with experimental data indicates that, among the considered masonry models, the Concrete Damaged Plasticity model under biaxial calibration gives the best overall performance. The TSAM is then used to study selected tunnel-masonry wall scenarios, confirming a significant effect of the constitutive model and its parameters on masonry wall response to tunnelling , particularly after volume losses where moderate damage is triggered. Also, as masonry stress paths are shown to concentrate in the tensile–compressive areas, with damage prediction being sensitive to the yield surface within this quadrant, numerical damage predictions must rely on the accurate calibration of the constitutive model in the tensile–compressive quadrants. This appraisal indicates that, in the context of routine structure modelling for tunnelling assessments, the selection of elastoplastic masonry models and their biaxial calibration have a non-negligible impact on the damage category estimate.
Empirical prediction of horizontal movements induced by tunnelling in fine-grained soils Eugene K. L. Wong, Andrea Franza, Giulia M. B. Viggiani Canadian Geotechnical Journal, 2025 For tunnelling in fine-grained soils, available evidence indicates that the focal depth of displacement vectors along the ground surface decreases with the transverse distance from the tunnel centre-line. Based on field and centrifuge observations, this paper presents a new empirical method in which the focal depth is a function of the transverse offset and, possibly, the tunnel volume loss. The comparison with experimental data from centrifuge experiments and case histories confirms the reliability of the proposed method, in terms of both surface horizontal displacements and strains. In particular, the predicted horizontal displacement profiles, both in terms of maximum value and extent, are in better agreement with the available experimental evidence than those obtained using the empirical and analytical methods currently adopted in design. Finally, an operational way to obtain the complete horizontal displacement field at the surface, near-surface, and at depths down to the tunnel crown is suggested and the importance of carrying out field monitoring for surface and subsurface horizontal displacements is highlighted.
A study of pile row barriers close to the retaining wall of a deep excavation to protect existing tunnels: physical testing and a case history Xu He, Andrea Franza, Xuedong Luo, Nan Jiang, Yanliang Yin Bulletin of Engineering Geology and the Environment, 2024 This paper investigates the use of a protective pile row barrier to mitigate the risk due to a deep excavation in soft soils adjacent to an existing tunnel. The study includes two reduced-scale 1 g model tests with and without the barrier, along with monitoring data from a case history in Wuhan, the Huazhong Science and Technology Industrial Park basement; physical testing and numerical sensitivity study results are compared to the case history to evaluate the barrier efficiency. The monitoring data show successful excavation and basement construction within allowable displacement thresholds in the presence of the barrier. The entire tunnel settled and translated towards the excavation, although different types of ovalization of the tunnel cross-sections were recorded depending on their alignment to the excavation (centre and corners). Experimental results indicate that the pile row barrier can withstand a portion of the soil pressure on the diaphragm wall, leading to a substantial reduction in tunnel bending moments and displacements; in particular, experimental results showed a greater percentage reduction in settlements than horizontal movements of the existing tunnel. When a pile row barrier is constructed in proximity to the retaining wall, it can help to minimise the detrimental effects of the deep excavation on the existing tunnel, similar to twin retaining wall scenarios.
Effects of relative density and dilatancy on stress and deformation arching of sand over an active trapdoor Xue-Yan Liu, Andrea Franza, Rafael Jimenez Computers and Geotechnics, 2024 This paper employs Discrete Element Method (DEM) simulations to investigate the influence of relative density on soil arching within a plane-strain active trapdoor scenario. For varying relative trapdoor depths, DEM simulations illustrate the key influence of dilatancy on displacement and strain fields and on stress rotation and trapdoor pressure, confirming that shear bands develop at the trapdoor depending on the soil’s dilation angle. The interplay between dilatancy and soil cover governs the arching phenomenon and the ground deformation mode; the significance of relative density is also highlighted by its effects on the principal stress rotation and ground reaction curves. To predict the minimum trapdoor pressure, we propose a Limit Equilibrium Method (LEM) solution that considers the type of failure mechanism (trapezoidal or triangular) and the lateral earth pressure as a function of the soil’s dilatancy and stress arching shape; this approach coincides with Terzaghi’s soil pressure concept at the critical state. LEM predictions of minimum and ultimate (or terminal) trapdoor pressure, and of shear deformation modes, are validated with our DEM results and with literature results. Finally, the impact of effective stresses and relative density on deformation patterns and design charts that quantify the minimum trapdoor pressure is discussed.
General Report–sustainability and resilience of underground infrastructure A. Franza Geotechnical Aspects of Underground Construction in Soft Ground, 2024 This General Report highlights key aspects of the papers included in the session on ‘Sustainability and resilience of underground infrastructure’. A variety of topics can be found in this session (e.g., excavations and geothermal systems), with contributions focusing on the design and construction aspects of deep excavations and tunnels. This indicates that civil engineers face the challenge of reducing over-engineering of underground infrastructure.
Effect of infill nonlinearity on frame response to tunnelling Y. Yu, A. Franza, L. Neves, A.M. Marshall Geotechnical Aspects of Underground Construction in Soft Ground, 2024 Tunnel construction is needed for infrastructure development in urban areas. However, underground excavation can detrimentally influence adjacent buildings; in particular, for framed structures with shallow foundations, damage would localise in the infill walls. This paper uses a two-stage analysis method (TSAM) to evaluate the effect of infill nonlinearity on the frame response to tunnelling. First, TSAM results are validated using centrifuge experimental and advanced numerical results. Then, the influence of the infill nonlinearity on the foundation displacements and building deformation parameters are analysed, considering both long and short structures. During this stage, the reinforced concrete (RC) frame and the endwall are modelled as elastic, while both elastic and advanced constitutive models are adopted for the masonry infills. Finally, the role of infill nonlinearity in frame shear and bending behaviours is investigated.
A multi-sensing monitoring system to study deterioration of a railway bridge 9th International Conference on Structural Health Monitoring of Intelligent Infrastructure Transferring Research into Practice Shmii 2019 Conference Proceedings, 2019
Structural health monitoring of a masonry viaduct with Fibre Bragg Grating sensors IABSE Symposium Guimaraes 2019 Towards A Resilient Built Environment Risk and Asset Management Report, 2019
Semi-analytical prediction of ground movements due to shallow tunnels in sand Geotechnical Engineering for Infrastructure and Development Proceedings of the Xvi European Conference on Soil Mechanics and Geotechnical Engineering Ecsmge 2015, 2015
Analytical investigation of soil deformation patterns above tunnels in sandy soil Geotechnical Engineering for Infrastructure and Development Proceedings of the Xvi European Conference on Soil Mechanics and Geotechnical Engineering Ecsmge 2015, 2015
RECENT SCHOLAR PUBLICATIONS
Underground energy storage using man-made CO2 hydrate geo-capsules O Lev-Yehudi, Q Ouyang, A Franza, N von Solms, A Klar Tunnelling and Underground Space Technology 168, 107203 , 2026 2026 Citations: 3
Introducing tunnel kinematic constraints into an elastic continuum formulation of tunnel–soil–pipeline interaction A Klar, A Franza, M Zhou, HW Huang Géotechnique 75 (13), 126-135 , 2025 2025 Citations: 12
Experimental study of sugar-induced sand cementation in dry conditions G Sorrentino, A Franza Geomechanics for Energy and the Environment, 100765 , 2025 2025 Citations: 1
Synthesis of CO2 hydrate capsules in partially water-saturated sediment as vessels for underground mechanical energy storage: promoting effect of tetrahydrofuran and cyclopentane Q Ouyang, O Lev-Yehudi, JS Pandey, A Franza, I Rocchi, A Klar, ... Fluid Phase Equilibria 595, 114428 , 2025 2025 Citations: 5
Pumped underground hydroelectric energy storage system in sand: an overview of the field trials in Foulum, Denmark A Franza, KK Sørensen, HH Stutz 3rd International Conference on Energy Geotechnics 2025 , 2025 2025
Required Research Steps Towards the Realization of CO2-Hydrate Geo-Capsules for Underground Mechanical Energy Storage A Klar, A Franza, N von Solms, OL Yehudi, AM Tang, Q Llabjani, ... 3rd International Conference on Energy Geotechnics 2025 , 2025 2025
Tunnelling-induced wall damage: An appraisal of elastoplastic constitutive models for masonry Y Yu, A Franza, B Ghiassi, LC Neves, AM Marshall Tunnelling and Underground Space Technology 156, 106240 , 2025 2025 Citations: 8
Semi-analytical model for three-dimensional tunnelling-induced movements in undrained soil A Franza, AGJ Ali, SB Ehlers ECCOMAS Thematic Conference on Computational Methods and Information Models … , 2025 2025
Ground movements induced by a deep excavation in Copenhagen: comparison of prediction methods with monitoring data A Hernandez-Guardado, F Petrella, A Franza ITA-AITES World Tunnel Congress 2025 (WTC 2025), 1460-1467 , 2025 2025
Empirical prediction of horizontal movements induced by tunnelling in fine-grained soils EKL Wong, A Franza, GMB Viggiani Canadian Geotechnical Journal 62 , 2025 2025 Citations: 2
Load transfer mechanisms for capped and uncapped non-displacement piles above tunnels: a centrifuge modelling study C Tang, A Franza, J Xu, AM Marshall Géotechnique 75 (4), 550–562 , 2025 2025 Citations: 8
A study of pile row barriers close to the retaining wall of a deep excavation to protect existing tunnels: physical testing and a case history X He, A Franza, X Luo, N Jiang, Y Yin Bulletin of Engineering Geology and the Environment 83 (10), 416 , 2024 2024 Citations: 4
Effects of relative density and dilatancy on stress and deformation arching of sand over an active trapdoor XY Liu, A Franza, R Jimenez Computers and Geotechnics 173, 106485 , 2024 2024 Citations: 15
A tz approach for the design of axially loaded piles in consolidating soil AE Detlefsen, A Franza, KK Sørensen Proceedings of the XVIII ECSMGE 2024, 448-451 , 2024 2024
Comparison of floating and end-bearing pile wall barriers for tunnelling in layered soil A Franza Proceedings of the XVIII ECSMGE 2024, 1626-1629 , 2024 2024 Citations: 2
A novel mechanical energy storage solution using underground CO2 hydrate capsules O Lev Yehudi, A Franza, N von Solms, A Klar Proceedings of the XVIII ECSMGE 2024, 3094-3099 , 2024 2024 Citations: 3
Setup and calibration of piles with FBG strain sensors in a geotechnical centrifuge C Tang, AM Marshall, CM Heron, A Franza, J Xu Proceedings of the XVIII ECSMGE 2024, 2667-2670 , 2024 2024 Citations: 1
Effect of infill nonlinearity on frame response to tunnelling Y Yu, A Franza, L Neves, AM Marshall Geotechnical Aspects of Underground Construction in Soft Ground (IS-Macau … , 2024 2024 Citations: 2
A continuum analysis of piles affected by an advancing tunnel excavation during centrifuge tests with a miniature TBM EKL Wong, A Franza, ASN Alagha, GMB Viggiani Geotechnical Aspects of Underground Construction in Soft Ground (IS-Macau … , 2024 2024 Citations: 2
General Report–sustainability and resilience of underground infrastructure A Franza Geotechnical Aspects of Underground Construction in Soft Ground (IS-Macau … , 2024 2024
MOST CITED SCHOLAR PUBLICATIONS
A simplified elastic analysis of tunnel-piled structure interaction A Franza, AM Marshall, T Haji, AO Abdelatif, S Carbonari, M Morici Tunnelling and Underground Space Technology 61, 104-121 , 2017 2017 Citations: 163
Greenfield tunnelling in sands: the effects of soil density and relative depth A Franza, AM Marshall, B Zhou Géotechnique 69 (4), 297-307 , 2019 2019 Citations: 139
Empirical and semi-analytical methods for evaluating tunnelling-induced ground movements in sands A Franza, AM Marshall Tunnelling and Underground Space Technology 88, 47-62 , 2019 2019 Citations: 89
Centrifuge Modeling Study of the Response of Piled Structures to Tunneling A Franza, AM Marshall Journal of Geotechnical and Geoenvironmental Engineering 144 (2), 04017109 , 2018 2018 Citations: 84
Elastoplastic solutions to predict tunneling-induced load redistribution and deformation of surface structures A Franza, MJ DeJong Journal of Geotechnical and Geoenvironmental Engineering 145 (4) , 2019 2019 Citations: 68
Centrifuge and real-time hybrid testing of tunnelling beneath piles and piled buildings A Franza, AM Marshall Journal of Geotechnical and Geoenvironmental Engineering 145 (3), 04018110 , 2019 2019 Citations: 61
Tunnel-framed building interaction: comparison between raft and separate footing foundations J Xu, A Franza, AM Marshall, N Losacco, D Boldini Géotechnique 71 (7), 631-644 , 2021 2021 Citations: 60
Timoshenko beam models for the coupled analysis of building response to tunnelling A Franza, S Acikgoz, MJ DeJong Tunnelling and Underground Space Technology 96, 103160 , 2020 2020 Citations: 60
Response of Framed Buildings on Raft Foundations to Tunneling J Xu, A Franza, AM Marshall Journal of Geotechnical and Geoenvironmental Engineering 146 (11), 04020120 , 2020 2020 Citations: 55
Tunnelling and its effects on piles and piled structures A Franza University of Nottingham , 2016 2016 Citations: 50
Continuum solutions for tunnel-building interaction and a modified framework for deformation prediction A Franza, S Ritter, MJ DeJong Géotechnique 70 (2), 108-122 , 2020 2020 Citations: 49
Investigation of soil–pile–structure interaction induced by vertical loads and tunnelling A Franza, C Zheng, AM Marshall, R Jimenez Computers and Geotechnics 139, 104386 , 2021 2021 Citations: 47
Building Deformation Caused by Tunneling: Centrifuge Modeling S Ritter, G Giardina, A Franza, MJ DeJong Journal of Geotechnical and Geoenvironmental Engineering 146 (5), 04020017 , 2020 2020 Citations: 44
Non-linear soil-pile interaction induced by ground settlements: pile displacements and internal forces A Franza, AM Marshall, R Jimenez Géotechnique 71 (3), 239-249 , 2021 2021 Citations: 42
Mixed empirical-numerical method for investigating tunneling effects on structures T Haji, AM Marshall, A Franza Tunnelling and Underground Space Technology 73, 92-104 , 2018 2018 Citations: 37
Numerical evaluation of scour effects on lateral behavior of pile groups in clay Z Wang, H Zhou, A Franza, H Liu Computers and Geotechnics 150, 104913 , 2022 2022 Citations: 36
Pile groups under vertical and inclined eccentric loads: Elastoplastic modelling for performance based design A Franza, B Sheil Computers and Geotechnics 135, 104092 , 2021 2021 Citations: 35
Tunneling-Induced Deformation of Bare Frame Structures on Sand: Numerical Study of Building Deformations D Boldini, N Losacco, A Franza, MJ DeJong, J Xu, AM Marshall Journal of Geotechnical and Geoenvironmental Engineering 147 (11) , 2021 2021 Citations: 30
Role of Shear Deformability on the Response of Tunnels and Pipelines to Single and Twin Tunneling A Franza, GMB Viggiani Journal of Geotechnical and Geoenvironmental Engineering 147 (12), 04021145 , 2021 2021 Citations: 25
Discussion: Greenfield tunnelling in sands: the effects of soil density and relative depth A Franza, AM Marshall, B Zhou, N Shirlaw, S Boone Géotechnique 70 (7), 639-646 , 2020 2020 Citations: 24
