Validation of numerical D.E.M. modelling of geogrid reinforced embankments for rockfall protection

Abstract

The adoption of reinforced embankments for rockfall and landslide protection purposes is an effective intervention for the reduction of risk and damages to civil facilities. These earth structures are manufactured with layers of compacted soil alternated with geosynthetics (e.g. geogrids and geotextiles) that are anchored to the outer quarterdeck frame or wrapped around it. This paper discusses the results obtained with a numerical simulation of the reinforced embankment carried out by means of a distinct element commercial (D.E.M.) code as particle code (P.F.C.). Several types of rock impacts on an embankment were simulated, varying block speeds, energies and geometrical impact conditions. Data from practical experiences of the authors and data from full-scale impact tests gathered from relevant literature, were used for the validation of the model. The main result of the work is the development of design operative suggestions that can support the selection of the design parameters of an embankment for rockfall protection purposes: its preliminary size based on impact energy level and induced damages can be outlined. The results of this provide guidance to designers and relevant stakeholders in the evaluation of risk scenarios arising from potential rock falls on infrastructures.