3D numerical modelling of a compensation grouting field trial in alluvial soils

A novel approach to minimizing ground surface heave during tunneling in alluvial soils has been validated through 3D numerical modeling, demonstrating that non-isotropic volumetric strains—where vertical expansion exceeds horizontal—can effectively replicate observed ground behavior. This finding supports the use of compensation grouting as a mitigation strategy for tunneling projects beneath sensitive urban areas, such as Florence's historic center. The study modeled a field trial involving twin tunnels, simulating grouted soil bulbs with enhanced stiffness and stepwise injection sequences from sleeved pipes. By comparing simulated displacements to real-world data, researchers confirmed the effectiveness of this technique in limiting settlements and structural damage risks. This work provides critical insights for future tunneling projects requiring precise ground control.

Boldini, D., Lusini, E., Spaggiari, C., & Fuoco, S. (2024). 3D numerical modelling of a compensation grouting field trial in alluvial soils. Geotechnical Aspects of Underground Construction in Soft Ground, 168–175. https://doi.org/10.1201/9781003413790-19