Maccaferri’s Rockfall RMC 100A, RMC 300A barriers were installed to match different degrees of estimated landslide risk in a road project connecting local cities in Mallorca.
Slope instability is a compound phenomenon that comprises not only landslides but also more refined developments such as soil creep. Buildings and groundwork such as transport facilities and pipelines situated within the limitations or in the path of a landslide are continuously at risk of being destroyed or damaged. If left undisturbed soil walls may remain stable for decades, however inadequately planned construction projects can sometimes activate or reactivate resting ancient slides.
Since the outset, Maccaferri has devoted itself to finding solutions for any range of engineering problems in the development world of construction. Aware of delicate geographic areas Maccaferri’s solutions are engineered to both complement the environment and strengthen its weaknesses.
In light of this is comes as no surprise that Maccaferri was sourced to resolve, and an array of slope instability queries on the course of that MA-10 local road in Mallorca, the Balearic Islands located between the municipalities of Andraitx and Estellencs.
The road’s massif had been eroded without generating slope stability until July 2013 when a pivotal forest fire compromised the situation. The fire destroyed nearly all the vegetation which in turn instigated elevated land erosion levels. This phenomenon gave rise to an increasing amount of dangerous rock fall incidences.
The technical solution adopted by Maccaferri to ensure the protection of the road was to construct several rockfall barriers whose aim it is to intercept and retain potentially unstable soil and larger rock formations. A detailed investigation was carried out involving the analysis of the most dangerous trajectories and energy calculation. Because the estimated risk varied largely across the area, Maccaferri devised a plan to install different barriers at various roadsides (1000 KJ & 3000 KJ barriers).
Altogether, 550 m long x 4 m high of a 1000 KJ barrier, and 220 m long x 6 m high of a 3000 KJ barrier were installed. These two rockfall barriers are formed by wire posts, upslope bracing cables, energy dissipating devices, and interception structures, formed by a ring net and reinforced by a hexagonal double twisted wire mesh. The pieces were made in Italy by Macafferri and installed at the building site by the specialist company Geotalud S.L.
The barriers have ETAG 027 compliance (Falling Rock Protection Kits) that provides class 3 and class 6 respectively, regarding the energy level, and category A in both for achieving a residual barrier height higher than 50 % of the nominal height after the crash test. The project was successfully absolved in November 2015 and continues to protect the road and civilians alike. The case study moreover exposes Maccaferri’s ability to customize its solutions according to the specificity of a case.