Before they can be used, rockfall nets must prove their capacity to withstand enormous forces and their compliance with strict performance requirements. As a consequence, the drapery that is designed to protect roads, railway lines and houses has a complex structure consisting of ring or wire mesh nets, (stranded) wire cables, steel posts and braking or arresting elements (Fig. 1).
Thus far it has been practically impossible to finalise designs and build such nets without conducting extensive full-scale tests. With a view to minimising development time and costs, GEOBRUGG and the SLF have jointly devised a new computer model for simulating rockfall nets. The project was sponsored by the CTI (Swiss Commission for Technology and Innovation).
New simulation model reduces development costs
When a flexible barrier arrests the fall of a rock, the rock's kinetic energy is absorbed by the deformation of the net. The way in which the net responds to the associated stresses depends primarily on the connections between its individual components. For the first time, the new simulation method conceived by the SLF allows the friction and interaction of the connecting elements within the net to be calculated. As demonstrated by comparisons with live tests, this approach significantly improves modelling of the behaviour encountered when rocks are arrested by flexible ring and wire mesh nets. It also allows net failure loads to be calculated.
This new method enables industrial enterprises to reduce the number of live tests substantially and to develop new wire net types more cost-effectively. It can also be fully integrated in CAD (computer aided design) processes, thus eliminating the need for complex wire frame models.
2013 - 2016