Analysis of waves generated by Zhaojun bridge rockfall in Xingshan county, three gorges reservoir, on December 28, 2012

Abstract

Rockfall waves generally cause damages to coastal infrastructures and people’s lives and properties. This paper presents and analyzes case about damages to the bridge and human activity areas caused by waves generated by rockfall. Based on the field survey on Zhaojun Bridge Rockfall in Xingshan County, Three Gorges Reservoir, it establishes a FSI (Fluidsolid Interaction) simplified model integrating RNG (Re-Normalisation Group) turbulence model and GMO (General Moving Objects) collision model through FLOW-3D, with simulated block volume of 6,240 m3. FSI analysis results show that the maximum wave generated by rockfall was 35 m, the body wave generated was about 1.2 m, the energy transfer rate is about 0.9 %. The direction of wave movement (145°) was skew with the running direction of Zhaojun Bridge (86.5°), and the major attack point of this accident was located on the east side of the Bridge. Simulation results are relatively consistent with the actual investigation. Impulse wave spray will also cause damages to economy and living zone. The key to wave hazards is the relative spatial relationship between human activity areas and waves. The FSI model based on the Navier-Stokes (N-S) equation can be used to analyze this relative relationship and provide reference for the study on the rockfall waves in tributary shallow waters.