Due to the correlation of natural vibration modes of skewed bridges, and the multi-directional nature of the earthquake ground motions; piers of skewed bridges would be subjected to combined axial, flexural and torsional loadings. The characteristic of combined loading of the piers depends upon several parameters including the strong ground motion characteristics and the structural system type. In this research seismic performance of a group of torsion sensitive skewed bridges with three different pier-deck connections is studied. Skew angles vary from 0° to 60°. Seismic performance of the bridges is investigated conducting bidirectional nonlinear time history analysis in OpenSees. Considering the effect of different pier-deck connection types, combined loading demand on the skewed piers is compared with those on the straight piers. On the basis of results, for both pinned and fixed piers, ductility demand increases with the skew angle. Opposed to pinned piers, fixed piers are subjected to combined torsional-flexural loadings, and the torsional demand increases with an increase in the skew angle. The value of torsional demand on fixed piers is limited to one half of cracking torque of the section (Tcr/2). Concerning to the collapse prevention criteria, 30 degree skew angle is found to be a threshold skew angle. For bridges with skew angles greater than 30 degree, applying monolithic pier-deck connections is more sensible.
Elnashai, A.S. Gencturk, B. Kwon, O.S. Al-Qadi, I. Hashash, Y. Roesler, J.R. Kim, S.J. Jeong, S.H. Dukes, J. and Valdivia, A. (2010) The Maule (Chile) Earthquake of February 27, 2010, Consequence Assessment and Case Studies. MAE Center, Report No. 10-04, 208 pp.
Zhao, B. and Taucer, F. (2010) Performance of Infrastructure During the May 12, 2008 Wenchuan Earthquake in China. Journal of Earthquake Engineering, 14(4), 578-600.
Yen, Ph. Chen, G. Yashinsky, M. Hashash, Y. Holub, C. Wang, K. and Guo, X. (2011a) China Earthquake Reconnaissance Report: Performance of Transportation Structures During the May 12, 2008, M7.9 Wenchuan Earthquake. The Federal Highway Administration, Publication No. FHWA-HRT-11-029 Oct, 54 pp.
Kawashima, K. Takahashi, Y. Ge, H. Wu, Z. and Zhang, J. (2009) Reconnaissance Report on Damage of Bridges in 2008 Wenchuan, China, Earthquake. Journal of Earthquake Engineering, 13, 965-996.
Ghobarah, A.A. and Tso, W.K. (1974) Seismic analysis of skewed highway bridges with intermediate supports. Earthquake Engineering and Structural Dynamics, 2(3), 235â48.
Meng, J.Y. and Lui, E.M. (2000) Seismic Analysis and Assessment of a Skew Highway Bridge. Engineering Structures, 22, 1433-1452.
Mohti, A.A. and Pekcan, G. (2008) Seismic Response of Skewed RC box-girder Bridges. Earthquake Engineering and Engineering Vibration, 7(4), 415-426.
Wilson, T. Mahmoud, H. and Chen, S. (2014) Seismic performance of skewed and curved reinforced concrete bridges in mountainous states. Engineering Structures 70, 158â167.
Deepu, S.P. Prajapat, K. and Chaudhuri, S.R. (2014) Seismic vulnerability of skew bridges under bi-directional ground motions. Engineering Structures 71, 150â160.
Hsu, H.L. & Liang L.L. (2003) Performance of hollow composite members subjected to cyclic eccentric loading. Journal of Earthquake Engineering and Structural dynamics, 32, 443-461.
Otsuka, H., Takeshita, E., Yabuki, W. Wang, Y., Yoshimura, T. and Tsunomoto, M. (2004) Study on the Seismic Performance of Reinforced Concrete Columns Subjected to Torsional Moment, Bending Moment and Axial Force. 13th World Conference on Earthquake Engineering, Vancouver, Paper No. 393.
Tirasit, P. & Kawashima, K. (2007) Seismic performance of square RC columns under combined cyclic Flexural and torsional loading. Journal of Earthquake Engineering, 11, 425-452.
Li, Q., Belarbi, A., & Prakash, S.S. (2010) Seismic Performance of square RC Bridge Columns under Combined loading including torsion with low shear. Paper No. 3011, Proceedings of the Earth and Space 2010 Conference: Engineering, Science, Construction and Operations in Challenging Enviroments. ASCE 2010.
Prakash S.S. (2009) Seismic Behavior of Circular RC bridge Columns under Combined Loading Including Torsion. Ph.D. Dissertation, Department of Civil and Environmental Engineering, University of Houston, 316 pp.
Prakash, S.S., Belarbi, A., and You, Y.M. (2010) Seismic Performance of Circular RC Columns Subjected to Axial, Bending, and Torsion with Low and Moderate Shear. Journal of Engineering Structures, Elsevier, 32(1), 46-59.
OpenSees, (2008) OpenSees Development Team, Open System for Earthquake Engineering Simulations, Version 2.3.0, [online]. Available from: http://opensees.berkeley.edu.
Pinto, A.V. Verzeletti, G. Pegon, P. Magonetto, G. Negro, P. and Guedes, J. (1996) Pseudo-Dynamic and shaking table tests on RC bridges ECOEST-PrEC8, Report No.5, Brussels.
CEN European Committee for Normalization, Eurocode 8, (2005) Design of Structures for Earthquake Resistance â Part2; Bridges, EN 1998-2.
Kappos, A.J. Manolis, G.D. and Moschonas, I.F. (2002) Seismic Assessment and design of R/C bridges with irregular configuration, including SSI effects. Engineering Structures, 24, 1337-1348.
IsakoviÂ´C, T. Lazaro, M. and Fischinger, M. (2008) Applicability of pushover methods for the seismic analysis of single column bent viaducts. Earthquake Engineering & Structural Dynamics, 37, 1185-1202.
Casarotti, Ch. and Pinho, R. (2006) Seismic response of continuous span bridges through fiber-based finite element analysis. Earthquake Engineering and Engineering Vibration, 5, 119-131.
Akbari, R. and Maalek, Sh. (2010) Adequacy of the Seismic Analysis Method for Single-column-bent Viaducts Considering Regularity and higher modes effects. Journal of vibration and control, 16, 827-852.
Aviram, A. Mackie, K.R. and StojadinoviÄ, B. (2008) Guidelines for Nonlinear Analysis of Bridge Structures in California, PEER Report. 2008/03.
Caltrans SDC, (2010) Caltrans seismic design criteria version 1.6. California Department of Transportation, Sacramento.
Menegotto, M. and Pinto, P.E. (1973) Method of Analysis for Cyclically Loaded R.C. Plane Frames Including Changes in Geometry and Non-elastic Behavior of Elements Under Combined Normal Force and Bending. In: Symposium on the Resistance and Ultimate Deformability of structures Acted on by Well Defined Repeated Loads, International Association for Bridge and Structural Engineering, Zurich, Switzerland. Lisbon: IABSE Report, Vol.13, Final Report, 15-22.
Mander, J.B. Priestley, M.J.N. and Park, R. (1988) Theoretical Stress-strain Model for confined Concrete. Journal of Structural Engineering, ASCE 114, 1804-1826.
Attarchain, N. Kalantari, A. and Moghaddam, A.S. (2013) Cyclic Behavior Modeling of Rectangular RC Bridge Piers Using OpenSees. Proceedings of the: 4th ECCOMAS Thematic Conference on Computational Methods in Structural Dynamics and Earthquake Engineering, COMPDYN 2013. Kos Island, Greece, 12â14 June.
Priestley, M.J.N. Seible, F. and Calvi, G.M. (1996) Seismic Design and Retrofit of Bridges. New York, NY, Wiley.
Baker, J.W. Lin, T. Shahi, S.K. and Jayaram, N. (2011) New Ground Motion Selection Procedures and Selected Motions for the PEER Transportation Research Program. PEER Report 2011/03.
AASHTO (2012) AASHTO LRFD Bridge Design Specification, American Association of State Highway and Transportation Officials.
Qiang, H. Xiuli, D. Zhou, Y. and Lee, G.C. (2013) Experimental study of hollow rectangular bridge column performance under vertical and cyclically bilateral loads. Earthquake Engineering and Engineering Vibration, 12(3), 433-445.
Qiang, H. Yulong, Z. Xiuli, D. Chao, H. and George, C.L. (2014) Experimental and numerical studies on seismic performance of hollow RC bridge columns, Earthquakes and Structures, 7(3), 251-265.
Attarchian, N., Kalantari, A., & S. Moghadam, A. (2016). Characteristics of combined loading demands on the piers of skewed bridges. Journal of Seismology and Earthquake Engineering, 18(3), 157-170.
Nahid Attarchian; Afshin Kalantari; Abdolreza S. Moghadam. "Characteristics of combined loading demands on the piers of skewed bridges". Journal of Seismology and Earthquake Engineering, 18, 3, 2016, 157-170.
Attarchian, N., Kalantari, A., S. Moghadam, A. (2016). 'Characteristics of combined loading demands on the piers of skewed bridges', Journal of Seismology and Earthquake Engineering, 18(3), pp. 157-170.
Attarchian, N., Kalantari, A., S. Moghadam, A. Characteristics of combined loading demands on the piers of skewed bridges. Journal of Seismology and Earthquake Engineering, 2016; 18(3): 157-170.