Analysis of three-dimensional movement characteristics of rockfall: A case study at a railway tunnel entrance in the southwestern mountainous area, China

Abstract

High unstable rock masses are widely distributed in the upper part of a railway tunnel entrance in the southwestern mountainous area, which causes serious hazards to the construction of the lower tunnel. The Rockfall Analyst software was used to simulate the three-dimensional movement track of five kinds of high unstable rock masses in the upper part of the tunnel, and it shows that the rockfalls in the study area have the characteristics of high bounce height, fast speed and high impact energy. There is no relation between the bounce height, the movement speed and the mass of rockfall, while the impact energy is proportional to the mass of rockfall. The analysis shows that multiple and comprehensive protective measures should be recommended for the protection of unstable rock masses in this area instead of single protective measure.

Keywords

• unstable rock mass
• rockfall
• movement characteristics
• tunnel entrance
• protection