Sp56 road rockfall barrier

Italy, Caoria-Canal San Bovo (TN)
PET woven geogrids with PVC coating as a structural element for the construction of reinforced soil as rockfall barrier

Problem:
along the Provincial Road SP56 in Caoria, between the villages of Caoria and Canal San Bovo, over the years there have been repeated events of rockslides and rockfalls on the roadway.
This has required the planning and the design of a series of works to guarantee the safety of drivers. To avoid dangerous situations, a first hypothesis was drawn up for the construction of a 1,700 m tunnel just uphill from the village of Canal San Bovo. But this situation only partially resolved the problem as it involved only the initial section of road. Therefore it was considered unsuitable. The choice considered economic and performing to solve this problem is the securing of the current road section using a number of different techniques, based on the situations point by point.
Specifically, from progressive km 1+570 to km 2+320, for a section 850 m long, it called for a rockfall barrier was built uphill using retained wall technique with consequent movement of the roadway downhill and construction of a rip rap embankment along the Vano River (as erosion control at the foot of the embankment). Furthermore, it called for a system for drainage and disposal of the rainfall from the slope above.

Solution:
for the construction of a rockfall barrier that guarantees the safety of the roadway under evaluation, from both falling rocks and avalanches yet at the same time minimizes its environmental impact, it was decided to use the retained walls technology with revegetation.
In addition to the usual internal, composite, external and global stability verifications, analyses were performed on the uphill slope to determine the trajectory and size of the expected rocks as well as the impact energy.
Following this investigation, it called for a barrier with an uphill slope of 60° and downhill slope of 70°, height 5.00 m, head width 3.00 m and base 5.00 m using as reinforcement Edilgrid polyester woven geogrids, PVC coated, with layers 50 cm spaced.

After a short time, the face of the barrier was completely grown in and perfectly integrated in the local environment.