Dynamic Analysis and Innovative Design of a Kilometer-Long Highway Bridge under Extreme Landslide Generated Wave Loading

Abstract

This paper focuses on the dynamic analysis and innovative design of a 1042 m long highway bridge under extreme Landslide Generated Wave (LGW) impact loading. The proposed bridge crosses a deep and wide river valley which will become a part of a large reservoir after a hydroelectric dam is constructed. A rare extreme landslide event could occur and generate fast-moving waves in the reservoir impinging large forces on the bridge. To investigate the wave impact loadings on the bridge, three-dimensional Computational Fluid Dynamics (CFD) modeling of wave propagations were completed by hydrotechnical specialists, which were then used to analyze the structural dynamic response and to obtain force and displacement demands for structural design via a time- stepping analysis of the bridge structure. The innovative design included the use of non-uniform single circular-shaped pier columns supported on a hexagon-shaped pile cap with axisymmetrically configured rock-socketed steel pipe piles to address directional uncertainty associated with LGW. The bridge is currently under construction.