Wooden rockfall barrier assessment and impact analysis

Wooden rockfall barriers offer a sustainable solution to rockfall problems, while the full potential of wood remains untapped with increasing demands for natural hazards management in a changing climate. In Switzerland some of the first rockfall protection barriers were made from recycled wooden railway sleepers. Others sourced round wood beam elements from local mountain forests providing protection from natural hazards. However, advances in steel-wire net rockfall protection solutions have superseded wooden alternatives and this sustainable solution is being neglected.

With the aim of documenting existing wooden rockfall barriers and their protective capacity. Field investigations of existing wooden rockfall barriers, their construction design, remaining wood quality and moisture content, along with environmental conditions and evidence of rockfall impact events were conducted. This contribution focuses on a rockfall event that impacted one of the documented wooden barriers, causing damages to the beams and system structure. Rockfall impact scars were traced from its release source to the impact with the wooden barrier and are used to apply classical methods in rockfall trajectory analysis. Damages to the wooden barrier system are used to back calculate the rockfall impact energies and compared to the trajectory analysis of the event. Through this study an initial foundation in defining the protective capacity of wooden rockfall barriers has been established. Initial results indicate a higher energy dissipation capacity of wooden rockfall protection barriers than previously assumed and warrants further investigation of this sustainable rockfall protection solution.