The Lima coast highway also know as “Costa Verde” was built in the sixties as a great space for leisure and enjoyment for citizens and as an alternative way to release the traffic from the main urban areas. Unfortunately, today it has become the opposite.

The high traffic of vehicles that move along this road and the constant vibrations that they produce, this added to the elements such as the sea breeze, the rains and the small earthquakes, generate rockfalls from the slope. These situation increased the accident rate of this road causing a series of accidents.

Until 2014, ten traffic accidents caused by rockfall were reported, many of them with fatal consequences. The most outstanding case was that of the little kid “Tiago” who was left in a coma after a stone fell on his head at the the district of Miraflores (Waikiki Beach) in January 2014.

Parallel to these accidents, the engineering of geosynthetics was advancing looking for alternative solutions to conventional ones (steel + concrete anchors) that became impractical and very expensive. This led to the finding in the geogrids a solution that helped to reduce the energy produced by the rockfall, minimizing the damage they could produce.

After many technical studies and previous experiences, it was possible to replicate these solutions in the Costa Verde. Thus, in February 2014, the Municipality of Lima began installing geogrids on the most critical slopes of the Costa Verde, between the districts of Miraflores and San Miguel.

To date, there are already approximately 492,000 square meters of installed geogrids, which have reduced the accidents in this way by rockfall to two in the last two years.

It is imposible to determine a definitive solution for the “Costa Verde”, due slopes there are stable but the real problema is an erosion control one. According to that, the unique way to solve this type of problem and that could be affordable is by the use of geogrid as an erosion control solution with médium service life . In this way we can go so far as to demonstrate that its use considerably reduces the siniestrality of this path by rockfall, not only with a low cost of supply and installation but also with a minimum maintenance cost.