a flexible three-module rock shed for rockfall protection: design and full-scale experimental investigation

Flexible rock sheds mainly consisting of flexible nets and vaulted steel structures are a new type of device engineered to stop rockfalls. full-scale experiments have been conducted on a flexible single-module rock shed in the last few years. because the mechanical characteristics of a flexible three-module rock shed are much different from those of a single-module system, a flexible three-module rock shed aimed at withstanding a rockfall with kinetic energy ranging from 100 to 250 kj is designed and built. according to the european testing standards (etag 027), full-scale experiments on the three-module rock shed are carried out under the impact of rock blocks with a service energy level (sel) of 100 kj and a maximum energy level (mel) of 250 kj. the flexible three-module rock shed could be put into service again and required no repair after the sel tests, but it needed simple maintenance before returning to service after the mel test. furthermore, the weakness parts of the three-module rock shed, including the arch beams between the longitudinal supports and the connections between the arch beams and the stand columns, needed extra reinforcement. in addition, the cross sections of the stand columns, the diameter of the hoop support cables and the windings in the ring sets could be reduced for optimal design.