Seismic Evaluation of Horizontally Curved Bridges Subjected to Near-Field Ground Motions

Abstract

Horizontally curved bridges have more complex seismic behavior than straight bridges and have been more vulnerable to earthquakes. The present study aimed to evaluate the seismic response of concrete bridges with straight and arched box girder decks in isolated and non-isolated states. The results indicated that increasing the curvature of the non-isolated bridge could increase the irregularity. In addition, increasing the curvature of the deck leads to an increase in shear force, bending moment, and displacement in the piers in the radial direction of the arc, and causes vulnerability of the piers in this direction. Further, in the deck of the bridge, the reduction of the arc radius, especially in the non-isolated bridges, considerably increases the radial shear force, torsion and minor bending moment of the deck. In both isolated and non-isolated cases, the demand in the piers and deck of the bridge under the influence of near-fault ground motions is greater than that of the far-field earthquakes. Seismic isolation results in reducing the force demand in the pier, and the deck of the bridge, leading to a reduction in the force demand rate caused by increasing the central arc angle on the bridge deck.

Influence of Abutment Stiffness and Strength on the Seismic Response of Horizontally Curved RC Bridges in Comparison with Equivalent Straight Bridges at Different Seismic Intensity Levels

“…Other parametric studies regarding the seismic response of curved steel I-girder bridges unanimously confrm that the radius of curvature had the most signifcant impact on the seismic performance of this class of bridges [22][23][24]. Minavand and Ashtiany [25] conducted a parametric study based on the model of Sadr Elevated Bridge, located in the northeast of Tehran, with a horizontally curved RC box-girder typology. Tey concluded that increasing the curvature of the deck leads to an increase in seismic displacement demand of piers, shear force, and bending moment demands of the deck and piers.…”

Geometric characteristics, local site and curvature radius effects on seismic vulnerability of multi-span concrete girder bridge

“…The results obtained for the stability coefficient with all kinds of overturning axes in multi-span continuous curved box girders show that the anti-overturning performance is very strong because more support means more effective constraints on the structure, especially when the radius is small (Luo, X.,2018). Minavand, M., & Ghafory-Ashtiany, M. (2019) have modelled the box deck of Sadr Bridge located in Teheran in straight and horizontally curved forms with four central arc angles. They have modelled the bridge in non-isolated and isolated states with a friction pendulum bearing (FPB).…”