Proposed Damage Index for Seismic Evaluation of RC Bridge Shear keys

Document Type : Research Article


1 Ph.D. Student, Faculty of Civil, Water and Environmental Engineering. Shahid Beheshti University, Tehran, Iran

2 Shahid Beheshti University


Shear keys are bridge components that support the superstructure in transverse direction and may experience large displacements and extensive damages during earthquakes. Shear keys are designed to limit damage to abutment walls and piles by restraining the transverse movements. The shear force transferred to the abutments is controlled by design and detailing of the shear keys. Damage to shear keys during earthquakes may affect significantly on seismic behavior of the abutments and consequently, the bridge system. In this paper, a damage index is proposed for damage assessment of the bridge shear keys. The proposed damage index is defined based on the friction behavior and the ratio of the energy dissipation capacity to input energy. To evaluate the reliability of the damage index in damage assessment of the shear keys, finite element models of shear keys units, previously tested under cyclic loadings, are developed and the proposed damage index is calculated. Also, seismic response of shear key specimens are obtained under seven earthquake records using incremental dynamic analysis and the damage index is calculated for the shear keys in different PGA values of earthquakes. The results indicate that the proposed damage index can predict the damage progression in shear keys throughout loading histories and can provide reliable values for damage levels of shear keys with respect to the experimental observations.


Main Subjects

[1] Caltrans, S., Caltrans seismic design criteria. 2010. California Department of Transportation, Sacramento.
[2] Bozorgzadeh, A., Megally. S., Restrepo, J., and Ashford, A.S.2004. “Capacity Evaluation of Exterior Sacrificial Shear Keys of Bridge Abutments”. Journal of .Bridge Engineering. 11,pp. 555-565.
[3] Megally, S. H., Silva, P. F., and Seible, F.2002. “Seismic response of external sacrificial shear keys”. Report No. SSRP-2001/23, Department of Structural Engineering, University of California San Diego.
[4] Silva, P. F., Megally, S., and Seible, F.2003. “Seismic performance of sacrificial interior shear keys” ACI journal, 100.pp177–187.
[5] Silva, P. F., Megally, S., and Seible, F.2003. Seismic performance of sacrificial interior shear keys”, Earthquake Spectra, 25. pp 643–664.
[6] Goel, R., and Chopra, A. 2008. “Role of Shear Keys in Seismic Behavior of Bridges Crossing Fault-Rupture Zones”. Journal of Bridge Engineering.
[7] Xiang N, and Li, J. 2016.”Seismic performance of highway bridges with different transverse unseating-prevention devices”. Journal of Bridge Engineering, 21 04016045.
[8] Xiang N, and Li, J. 2018. “Effect of exterior concrete shear keys on the seismic performance of laminated rubber bearing-supported highway bridges in China” Soli Dynamic and Earthquake Engineering. 12.pp 185-197.
[9] Ghobrah, A., Abou-Elfath, H., and Biddah, A.1999. “Response based damage assessment of structures. Earthquake Engineering and Structural Dynamic” 28 pp 79-104.
[10] Mahboubi, S. and Shiravand, M.R.2018. “A proposed input energy-based damage index for RC bridge piers”. Journal of Bridge Engineering. 24. pp1-19. 10.1061/ (ASCE)BE.1943-5592.0001326.
[11] Kunnath, S. K., A. El-Bahy, A. W. Taylor, and W. C. Stone. 1997. “Cumulative seismic damage of reinforced concrete bridge piers”. Buffalo, NY: State Univ. of New York at Buffalo, National Center for Earthquake Engineering Research.
[12] Mander, J. B., and C. T. Cheng. 1995. Renewable hinge detailing for bridge columns. In Vol. 3 of Proc., Pacific Conf. on Earthquake Engineering, 197–206. Melbourne, Australia: Australian Earthquake Engineering Society.
[13] Park. Y.J., A., A.H.1985. “Mechanistic seismic damage model for reinforced concrete”. Journal of Structural Engineering. 111. pp. 722-739.
[14] Teran-Gilmore, A., Sanchez-Badillo, A.  and EspinosaJohnson, M. 2010. “Performance-based seismic design of reinforced concrete ductile buildings subjected to large energy demands”. Earthquake Structure. 1. pp. 69–91.
[15] Bassam, A., Iranmanesh, A., and Ansari, F. 2011. “A simple quantitative approach for post-earthquake damage assessment of flexure dominant reinforced concrete bridges”. Engineering Structure, 33 pp.3218-3225.
[16] Jara, J. M., Lopez, M.G., Jara, M., and Olmos, B.A. 2014. “Rotation and damage index demands for RC Mediumlength span bridges”. Engineering Structure. 75 pp. 205-217.
[17] Powell, G. H., and R. Allahabadi. 1988. “Seismic damage prediction by deterministic methods: Concepts and procedures”, Earthquake Engineering and Structural Dynamic, 16. pp 719–734.
[18] Bali, G.2014. Parametric Study of Bridge Response under Bidirectional Earthquake Loading with Nonlinear Shear Key and Columns. MSc Thesis.  Faculty of the Department of Civil Engineering California State University, Sacramento.
[19] Bi, K. and Hao, H.2013. Influence of Shear Keys on the Seismic Behavior of Bridge Structures to spatially varying ground motions. 23rd Australasian Conf. on the Mechanics of Structures and Materials (ACMSM23)Byron Bay, Australia, 9-12 December (2013), S.T. Smith (Ed.).
[20] Zabihi-Samani, M., and Ghanooni-Bagha, M. 2018. “Optimal Semi-active Structural Control with a Wavelet-Based Cuckoo-Search Fuzzy Logic Controller”, Iranian Journal of Science and Technology, Transactions of Civil Engineering.
[21] Zabihi-Samani, M.2019.  “Design of Optimal Slit Steel Damper Under Cyclic Loading for Special Moment Frame by Cuckoo Search”. International Journal of Steel Structures.
[22] Sabbagh-Yazdi,S.R., Farhoudi, A. and Zabihi-Samani, M. 2019. “Transient Galerkin finite volume solution of dynamic stress intensity factors”. Asian Journal of Civil Engineering.