Milan MM4 Lorenteggio

The main goals of the Milan Metro line 4 (M4) project are:

• to realize a new diametrical line from East to West, in order to connect through the historical centre some highly populated urban areas that are not well served by public transport such as metro line, railways, bus;
• to interconnect with the whole railway system, urban and regional;
• to realize a direct connection between the city centre and Milan Linate Airport (well known as the “city airport”).

The monitoring of the underpass allowed to control the geometry of the railway (longitudinal track deformation and rail cant) during the excavation done with 2 TBM, without interrupting or reducing the railway traffic. In case of an overcoming of the configured threshold, an alarm message reached the appointed people.
The monitoring of stations is divided into the monitoring of the D-walls through load cells and inclinometer, and the monitoring of the buildings with crackmeters, tiltmeters and H-Level settlement gauges. Manual and automatic readings allowed to verify the design hypothesis.