Retaining System Against Rockfall Near a Highway in Vietnam—A Case Study

Abstract

In this paper, a study was performed to investigate the rock fall event from km 18 + 980 to km 19 + 120 near the Halong-Vandon highway in Vietnam. The total area affected by rock fall was approximately 140 m long and 50 m high. This event took place as a result of the excavation during construction of the highway, which had removed part of the mountain and caused unbalance of the remaining slope. The stratigraphy was mainly composed of fairly-weathered rock. The topography of the location was investigated using Unmanned Aerial Vehicle (UAV) together with manual measurement. The protective measure, which had been applied successfully to the location, was also introduced. Particularly, the retaining system was composed of rock bolts, wire mesh, and an anchored wall. The rock bolts together with wire mesh were adopted to protect against rockfall at the top of the mountain whereas the anchored wall was constructed at the bottom of the mountain to stabilize this part.