Consolidation and stabilization of the supporting soil of a section of the Milan tramway line

Uretek was called in to study the case and, thanks to its solution for the consolidation of foundations, was able to solve the problem.

The tram line that crosses a well-known square in Milan had stability problems as it was sinking with the traffic of vehicles and the tram itself.

Uretek was called in to study the case and, thanks to its solution for the consolidation of foundations, was able to solve the problem.

The objective of Uretek’s intervention was to consolidate and compact the soil at the base of the sleepers supporting the rails in order to limit vibrations and movement. To this end, a localized treatment was carried out on 6 sleepers on one of the two tracks that cross Piazza XXIV Maggio.

The treatment was applied at the base of the track, on the ballast layer and the underlying foundation soil to a depth of 1m below the ballast, to consolidate it and limit possible differential settlements that could compromise the durability and functionality of the structure.

To carry out the intervention, 3 boreholes were drilled in each sleeper and injection cannulas were inserted under the basis of each sleeper to perform the resin injections. A very fast intervention that was carried out in 4 hours, thus avoiding any inconvenience to the tram traffic.

The entire intervention was monitored in real time to offer the greatest control over it. Track vibration monitoring was carried out by placing two accelerometers, one on the treated track and the other on the adjacent untreated track. Acceleration reduction of between 33% and 76% was recorded at all times. The intervention was a complete success.