Seismic performance of skewed and curved reinforced concrete bridges in mountainous states

• Seismic performance of both skewed and curved bridges not previously studied.
• The seismic performance of combinations of skewed and curved bridges is evaluated.
• Typical Colorado bridge detailing is used for a low-moderate seismic region.
• Bridges are evaluated using time-history analysis and detailed 3-D FE models.
• Insights made on curvature, skew, loading direction and support condition.

A number of skewed and curved highway bridges have experienced damage or collapse due to seismic events, and has most recently been observed during the Chile earthquake in 2010. In the Mountain West region, bridges integrating skew and curvature are becoming an increasingly prominent component of modern highway transportation systems due to their ability to accommodate geometric restrictions imposed by existing highway components. There is however very little information available on the combined effects of skew and curvature on the seismic performance of Reinforced Concrete (RC) bridges. A comprehensive performance analysis is performed on eight bridge configurations of various degrees of skew and curvature with low-to-moderate seismic excitations which are characteristic of the Mountain West region. Nonlinear time-history analysis is carried out on each bridge configuration using detailed finite element (FE) models. The results show a considerable impact on the seismic performance due to the effects of skew and curvature, with stacking effects observed in the combined geometries. Insights on the complexities of curvature, skew, loading direction and support condition are also made, which may lend themselves to more informed design decisions for practicing engineers in the future.