With reference to the landslide that hit «Madonna del Monte» viaduct on the Torino-Savona toll-road, Autostrada dei Fiori discloses that yesterday a huge landslide event happened (around 20.000/30.000 cubic meters) in a region classified as low hydrogeologic risk and not belonging to the Concession company.
Moreover, the particular shape of the hillside, formed by an intermediate part with a very relevant inclination, lead to a landslide formed by debris and big trees, with an high speed, between 10 and 20 meters per second.
This amount of debris hit a column of the bridge, composed by 4 elements with horizontal links with high quantity of energy. Missing the vertical support for one of the two spans, the same fell down with a rotating movement in the same direction of the landslide. The other span remained in the original position on the second row of columns without no sign of vertical neither horizontal shifts.
It is preliminary observed that the event must be considered absolutely unpredictable and the landslide realized a quantity of energy much higher than the one the bridge could technically absorbed. The bridge showed, indeed, a significant strength considering that the impact of the landslide didn’t cause damages to the other linked parts of the infrastructure.
The landslide partially involved the opposite carriage way that connects Savona to Torino, set 50 meters downstream, racking up debris near the foundation of one of the bridge column.
So far, the Civil Protection is estimating the real geometric of the landslide and evaluating the risk of further landslides.
Based on these news, Autostrada dei Fiori Company will set the protective measures of the foundation of the column of the opposite carriage way in order to open it safely, considering that the check of the joints of the various bridge spans didn’t show any misalignment due to the action of the landslide.
Finally, Autostrada dei Fiori Concession started the process to build up the new bridge, developing engineering activities and procurement.
The construction timing of the new bridge, with a single span in order to completely climb over the landslide area and so to disengaging similar events, is estimated in 3, maximum 4 months, once got the availability of the area and all the necessary authorizations.