Journal of Constructional Steel Research 59 (2003) 1101–1117 www.elsevier.com/locate/jcsr Cross-frame and lateral bracing influence on curved steel bridge free vibration response H. Maneetes, D.G. Linzell * Department of Civil and Environmental Engineering, Pennsylvania State University, State College, PA 16802, USA Received 4 September 2002; received in revised form 17 January 2003; accepted 12 February 2003 Abstract Accurately quantifying the free vibration response of curved steel bridges has been a topic of interest for researchers and practitioners. This study examines the response of an experi- mental, single-span, noncomposite, curved I-girder bridge superstructure during free vibration. Finite element models of the experimental bridge system, which was tested for the FHWA Curved Steel Bridge Research Project (CSBRP), were constructed and calibrated against experimental data from dynamic investigations of the bridge by the Virginia Transportation Research Center (VTRC). Parametric studies of the experimental curved bridge system were conducted using these finite element models to investigate the effects of cross-frame and lateral bracing parameters on the structure’s free vibration response.  2003 Elsevier Science Ltd. All rights reserved. Keywords: Curved bridge; Cross-frame; Lateral bracing; Free vibration; Construction; Finite element 1. Introduction Horizontally curved bridges are commonly used in highway interchanges in large urban areas. Due to their curvature, the behavior of horizontally curved bridges is more complex than straight bridges. In addition to vertical shear and bending stresses present in straight girder systems, curved girders must also resist torsion that occurs due to curvature. So that these torsional effects can be effectively resisted by the curved girder system, both during construction and while in-service, cross-frames * Corresponding author. Tel.: +814-863-8609; fax: +814-863-7304. E-mail address: dlinzell@engr.psu.edu (D.G. Linzell). 0143-974X/03/$ - see front matter  2003 Elsevier Science Ltd. All rights reserved. doi:10.1016/S0143-974X(03)00032-4