Leveraging FEA and InSAR for Accurate Settlement Analysis
Hutton Hub – Hertfordshire, United Kingdom
Highlights
The University of Hertfordshire’s new Hutton Hub building, designed for the Student Union, features a striking glass façade. This design element necessitated precise control over the differential settlement of its foundation, making the structural engineering process both critical and challenging.
Site Investigation and Ground Conditions
The Hutton Hub site investigation revealed complex subsurface conditions, with solution and mining features extending up to 25 meters deep. Infill material varied from soft clay to dense sand and chalk, creating a risk of uneven settlement that threatened the glass façade’s integrity. Initially, a raft foundation was deemed unsuitable due to differential settlement risks. However, engineers conducted extensive multi-phase investigations to map the soil’s mechanical behaviour in 3D, providing critical data for further analysis.
High Plasticity Clay and Groundwater Fluctuations
To assess the feasibility of a raft foundation, engineers developed a 3D Finite Element Analysis (FEA) model incorporating:
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Material Properties: Representing varied infill from soft clay to dense chalk.
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Boundary Conditions: Simulating real-world constraints for accuracy.
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Structural Loads: Factoring in shear and core walls.
Using advanced FEA software, the model simulated foundation-ground interaction, including the stiffening effects of shear and core walls. Results showed the raft foundation could effectively span soft spots, with predicted differential settlements significantly lower than conventional estimates, confirming its viability.
Validation with InSAR Technology
While FEA offered a strong predictive model, validation was crucial. Interferometric Synthetic Aperture Radar (InSAR) technology, which detects ground deformation with millimetre precision, provided this confirmation.
Post-construction, InSAR analysis showed settlements of under 3mm over 18 months, validating the FEA model’s accuracy and ensuring the glass façade remained unaffected by differential settlement.
Cost Savings and Environmental Benefits
The successful use of FEA and InSAR validated the raft foundation, eliminating the need for piling and leading to:
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Cost Savings: £1 million saved by avoiding piling costs.
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Time Efficiency: Reduced construction delays.
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Environmental Benefits: Lower CO₂ emissions for a more sustainable build.
Conclusion
The University of Hertfordshire’s Hutton Hub highlights the power of combining FEA and InSAR for precise settlement analysis. By integrating detailed site investigations, advanced modelling, and remote sensing validation, the project balanced technical excellence with practical constraints. This approach ensured structural integrity while delivering significant economic and environmental benefits—a win for both engineering and sustainability.
Want to learn more? Contact Geofem today to discover how InSAR can support your geotechnical needs.
