Trento Proposes Road Removals and Tunnels to Secure Gardesana Access
The highest concession that the Provincia Autonoma di Trento feels capable of offering regarding the concerns of Limone (jointly shared by Riva) about the Gardesana road is to wait until next June to make the final decision, which will determine whether, before the gallery reaching the Sperone, it will still be permitted for some civil vehicles to venture beneath the shearless escarpments of the Rocchetta’s slopes between Riva and Sperone.
The operation, announced yesterday by Assessore Casagranda, assisted by Engineer De Col, involves several steps. It will start, as soon as the technical timing of the contracts carried out under an emergency procedure allows, with two coordinated interventions.
The first: an extremely decisive removal of the mountain slopes, utilizing the expertise of Engineer Castelli who identified several critical points. For example, a twenty-cubic-meter boulder teetering in unstable balance right next to the spot where the last landslide detached will be blown up and sent crashing downward. Dozens of similar cases will meet the same fate.
Simultaneously, work will commence on the Gardesana Occidentale to excavate a tunnel perpendicular to the future Riva-Ponale route. The starting point has been set at the midpoint of the 1200-meter planned gallery to Sperone, near the natural rock tunnel named Psiche, located just south of the two last rockfall barriers built last year.
This tunnel, which will plunge straight into the rock for 150 meters, will serve multiple purposes. Primarily, it will enable work to begin on the future Riva-Sperone tunnel from four points, providing a clear advantage in completion times: from Riva, Sperone, and from mid-galleria towards the north and south.
Secondly, it will provide a credible sampling of the subsequent rock strata that the main tunnel will have to cross. Finally, concerning the removal work, the numerous explosions in the lower tunnel will cause a series of shocks to the entire overlying wall, dislodging potentially hazardous or unstable rocks.
When this initial phase of interventions (removal on the wall and construction of the 150-meter “service” tunnel: an estimated expenditure of 7-8 billion lira) is completed, June will arrive.
At that point, the two experts, Engineer Castelli from the Trentino side and the technician chosen by the Province of Brescia, will be able to determine if the minimum safety conditions are met to allow transit, even if limited to certain hours of the day.
By June, that is, in four to five months, the two engineers will have a significantly altered picture in front of them. If, even after four months of removal and wall clearing, safety is not assured, there will be no choice but to accept the situation.