Journal of the Korean Geo-Environmental Society ISSN:1598-0820(Print) 2714-1233(Online) 한국지반환경공학회 논문집

In mountainous regions where road and railway routes traverse steep terrain, structural damage caused by natural hazards such as rockfalls and debris flows occurs frequently. To protect against high-energy rockfalls, rock-shed tunnels must ensure structural stability, making accurate estimation of impact energy and structural analysis essential. This study compares two methods for estimating rockfall impact energy applied to the structural design of rock shed tunnels: a theoretical formula proposed by the Ministry of Land, Infrastructure and Transport (2024) and a numerical simulation using the Rocfall program. While the theoretical formula allows for simplified and conservative design, it has limitations in accurately reflecting complex slope geometries. In contrast, the Rocfall based numerical approach provides a more realistic analysis of impact energy by incorporating terrain conditions and rockfall dynamics. To evaluate and compare both methods, rockfall scenarios were simulated with slope heights ranging from 10 to 30 meters, a rock mass of 10 tons, and varying slope gradients. The findings highlight the strengths and limitations of each approach and aim to provide more rational design criteria for practical application in rock-shed tunnel engineering.