Bemessungsvorschlag für Steinschlagschutzdämme

Design proposal for rock fall embankments.

At the time being there are no state of the art methods to be applied in the design of rock fall embankments. As rock fall net-fences have a restricted energy absorption capacity, currently being certified up to 8,000 kJ, rock fall protection for higher design energies is often realized by the construction of an embankment. The prediction of the behaviour of rock fall embankments for dynamic impacts by standard geotechnical methods is not possible due to the lack of methods to determine an equivalent static force. Existing approaches to provide static equivalent forces are based on tests on damping layers overlaying stiff reinforced concrete structures such as galleries and cannot be transferred to structures consisting of soil only. To provide a code of practice for the design of rock fall embankments subjected to highly dynamic loading, model-tests on embankments of various construction types and geometries were carried out in a scale of 1:33. With these model tests it was possible to describe the geometry of the body of failure induced by the dynamic impact for different loading cases. Based on the results of the model tests a method to determine a static equivalent force dependency on the geometry of the embankment and different types of construction was developed. With this static equivalent force the proof of ultimate limit state (design situation DS 3 according to EC 7 - ÖNORM B 1997-1-1) can be performed with standard methods of soil mechanics.