The German Federal Railway Authority (EBA) has issued a new approval for an alternative slope drapery system. Experts now have the option to choose between alternative, approved concepts to fit their solution to the project requirements individually. With the new EBA approval, a manufacturer emerges, who is able to cover the entire range of protective rockfall protection measures. The new Austrian standard ONR 24810 has increased the measures for rockfall protection, compared to ETAG 027. The competent experts of the Austrian Railways ÖBB, subsequently have developed their own criteria catalogue, based on the ONR, which now include requirements for handling, sustainability and performance. In contrast to one single standard product solution, that defines just one netting type for the entire field of slope protection measures, a modular netting system offers potential savings. The proposed contribution compares the different requirements in Germany and Austria, and responds to the full range of rockfall protection measures, including an advanced corrosion protection in accordance to DIN EN 10233-3.
Introduction and Overview
In the last years the German Railway Authority (EBA) requires approval for an alternative slope drapery system. In summer 2014 the German Authority issued an approval document for the Maccaferri Steelgrid HR. For the first time experts involved in the assessment, planning, procurement and construction have an option to choose among approved systems, and provide sound engineering solutions to meet the project requirements.
Along with the EBA approval, manufacturers can cover a broad range of rock fall protective measures. They include modular steel wire meshes with multiple grades of strength (35-250 kN/m), rock fall barriers with energy classes 500-8,600 kJ (ETAG 027 and CE certified), debris flow barriers and rock fall protection embankments, made with modular steel wire mesh reinforcing elements. In Austria, with the release of the new Ö-Norm ONR 24810:2013, requirements have become more comprehensive than just complying with the ETAG 027 crash test in rock fall protection measures. Further to ONR 24810, the Austrian Railways ÖBB later developed their own criteria, which includes requirements for handling and sustainability as well, in addition to the performance requirements. Another aspect deemed important for sustainability is in fact the durability against corrosive effects in the long-term performance of the protection measures.
Although the issue of corrosion resistance found an interest in Germany for gabion applications (and salt spray test for more than 3000 hrs are mandatory requirements), in rock fall applications Authorities are still not remarkably sensitive to this aspect, as opposed to Scandinavian countries where, due to the location along the coast of a considerable part of the infrastructure network, slope drapery systems require the highest standards for durability.
Recent developments in organic coatings on the steel wire allow today a full protection of the rock fall systems meshes with a remarkable increase in the life expectancy. Even after 6000 hours of test exposure no corrosion is detected, as confirmed by accredited German Institutes. Moreover, the realease of DIN EN 10223-3, Annex A, provides an assumed working life for various environment conditions C2-CX, in relation to the coating type, and in the case of polymer coated steel wire assumes a life expectancy of 120 years.