TF-445 road is an insular road that connects the local municipality of Buenavista del Norte, with Punta de Teno’s lighthouse. It is located on the northwest coast of Tenerife, Canary Islands (Spain).
It runs through a very mountainous abrupt area with very high slopes, formed by basaltic castings interspersed with slags and other volcanic materials. Softer materials are constantly eroded by rain and wind, leaving that way toughest materials in cantilever with a very high risk of falling.
Over the course of many years, there have been constant rock falls that have threatened the road safety, and furthermore, caused the road closure on several occasions.
The technical solution adopted is the protection of the road by placing up several rock fall barriers whose aim is the interception and retention of potentially unstable rocks. However, a future phase that shall increase the road safety is planned.
In this case, a detailed investigation was carried out involving the analysis of the most dangerous trajectories and the energy calculation.
Due to the fact that the estimated risk was not the same all over the place, two different barriers were determined.
A 110 m long x 8 m high 3000 KJ barrier, and a 140 m long x 7 m high 5000 KJ barrier were selected. These two rock fall barriers are formed by posts, upslope bracing cables, energy dissipating devices, and interception structures, which are formed by ring nets at the same time reinforced by hexagonal double twisted wire meshes.
They were made in Italy by Officine Maccaferri Italy and installed in the job site by the specialist company Villar Trabajos Verticales. They have ETAG 027 compliance (Falling Rock Protection Kits) which provides class 6 and class 8 respectively, regarding the energy level, and category A in both for achieving a barrier residual height higher than 50 % of the nominal height after the crash test.