SIMPLIFIED METHOD FOR SEISMIC PERFORMANCE ASSESSMENT OF SKEWED BRIDGES

Damage and seismic movements observed in bridges in recent earthquakes have indicated that the response and failure modes of bridges with skew-angled abutments are sig- nificantly different from those of bridges with normal abutments. One significant manifesta- tion of this difference is the inherent tendency of skewed bridges to rotate about their vertical axes under seismic excitation. In this study, with the aforementioned field observations in mind, we have conducted parametric response-sensitivity analyses in an effort to identify the key parameters that control the seismic behavior of skewed bridges. This paper describes our simplified modeling technique, which takes bridge-abutment interaction into account, along with the analysis results. Three short bridges located in California were used as subjects. These bridges have different arrangements of number of spans and number of columns per bent; and through nonlinear time-history analyses, we investigated the sensitivity of their var- ious responses to variations in parameters such as torsional stiffness, span arrangement, col- umn height, abutment skew angle, and ground motion characteristics.

[1]  G. G. Stokes.  "J." , 1890, The New Yale Book of Quotations.

[2]  Joseph P. Nicoletti,et al.  Seismic Design and Retrofit of Bridges , 1996 .

[3]  Mjn Priestley,et al.  Seismic Design and Retrofit of Bridges , 1996 .

[4]  Eric M. Lui,et al.  Seismic analysis and assessment of a skew highway bridge , 2000 .

[5]  Paul C. Jennings,et al.  Engineering features of the San Fernando earthquake of February 9, 1971 , 1971 .

[6]  Kyle M. Rollins,et al.  Nonlinear Soil-Abutment-Bridge Structure Interaction for Seismic Performance-Based Design , 2007 .

[7]  David P. Billington,et al.  Analysis of Seismic Failure in Skew RC Bridge , 1991 .

[8]  Kevin R. Mackie,et al.  Performance‐based seismic bridge design for damage and loss limit states , 2007 .

[9]  Stavroula J. Pantazopoulou,et al.  Response simulation and seismic assessment of highway overcrossings , 2009 .

[10]  M. Saiid Saiidi,et al.  Nonlinear Earthquake Response Modeling of a Large-Scale Two-Span Concrete Bridge , 2009 .

[11]  Filip C. Filippou,et al.  Evaluation of Nonlinear Frame Finite-Element Models , 1997 .

[12]  W. K. Tso,et al.  Seismic analysis of skewed highway bridges with intermediate supports , 1973 .

[13]  Jonathan P. Stewart,et al.  Validated Simulation Models for Lateral Response of Bridge Abutments with Typical Backfills , 2010 .

[14]  Sami Megally,et al.  Capacity Evaluation of Exterior Sacrificial Shear Keys of Bridge Abutments , 2006 .

[15]  Andreas J. Kappos,et al.  Extension of modal pushover analysis to seismic assessment of bridges , 2006 .