Large-scale physical modeling study on the interaction between rockfall and flexible barrier

Flexible barriers have been widely applied in rockfall mitigation in recent years. However, the behavior of flexible barriers under the impact of boulders is still not fully understood. To investigate the interaction between a flexible barrier and a falling boulder, a large-scale physical modeling device has been constructed at a site in Hong Kong. Using this device, large-scale impact tests using boulders with different diameters were conducted. Test results are presented and analyzed in this paper. The motion of the boulder during impact is traced and analyzed. The impact forces on the flexible ring net and the supporting structures are measured and compared. From the comparison, the impact reduction rates (IRR) of boulders with different diameters are calculated. Moreover, a simple approach for estimating the impact loading of a boulder on a flexible barrier is proposed in this study. This approach is calibrated and verified using measured impact forces in the tests.