Assessing the effects of constructing the Colosseo/Fori Imperiali station on the Basilica di Massenzio in Rome, Italy

摘要

Colosseo/Fori Imperiali is a key station of the San Giovanni-Venezia stretch on the new Metro Line C in Rome, Italy. It provides interchange facilities to the existing Line B and direct access to some of Rome's most important monuments, including the Colosseum and the Basilica di Massenzio. The works are ongoing in 2014 and the station comprises excavations for the main station box, which is in excess of 30 m deep, approximately 130 m long and up to 42 m wide, as well as for a sub-station and station entrances, which are around 8 m depth. There is a minimum distance of approximately 10 m between the station and the Basilica, which was the largest building of the Roman Forum but its remains are now in a cracked and vulnerable condition. Given the historic importance of the Basilica and the close proximity of the station, ground movements had to be predicted and their potential effects on the monument required careful consideration. This paper presents the 3D FE analysis that was undertaken to enable this assessment and determine requirements for additional mitigation measures. Some mitigation measures were already implemented, including alignment refinement to optimize the box configuration and to position it as far from the monument as practicable, the use of stiff retaining wall systems, sufficiently deep to cut-off groundwater flow, and emphasis on good construction control. The analysis results demonstrated that, despite the large depth and size of the excavation for the final station box configuration, the effects on the monument would be minimal and so active intervention at the Basilica could be limited to detailed monitoring, temporary support and some strengthening work.