Seismic Response Assessment of Bridges with Group Pile Foundation subjected to Near-fault Ground Excitations

• Main Authors: Chun-Yao Wang, 王俊曜
• Other Authors: Shin-Tai Song
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/9cdanz

博士 === 國立中興大學 === 土木工程學系所 === 106 === For a bridge subjected to near-fault ground motion, the strong ground excitation produces a large lateral displacement in the bridge. Additionally, the combined effect of gravity load acting through the large lateral displacement amplifies the inelastic deformation at the critical section of the bridge. The long-period pulse of the near-fault ground motion usually causes a bias response in one direction, which results in a large permanent deformation of the bridge. Bridges located in near-fault regions are vulnerable to severe damage during earthquakes. This paper presents a nonlinear time history analysis conducted through a finite element analysis platform to simulate bridge responses under near-fault ground motion. The finite element model uses fiber beam–column elements to model the reinforced concrete columns and piles and employs the beam-on-Winkler-foundation approach to simulate soil-pile interaction. The bridge is assumed to be located in three different sites with the soil profile classified as stiff soil, medium soil, and soft soil. Three near-fault ground motion records are selected as the imposed seismic demands, and one-dimensional site response analyses are applied to assess the free-field soil profile response. The structural geometric nonlinearity effect, which is recognized as effect, is also considered in the analysis. Results show the effect of ground motion characteristics and soil profile variations in the maximum seismic response and inelastic deformation of the structure. The correlation between the maximum lateral displacement and residual displacement of the bridge is also studied.