04 October 2012
The first form-travellers have been erected at the US$125 million Antlers Bridge replacement on I-5 in Shasta County, California.
The new cast-in-place prestressed segmental box girder superstructure consists of five spans, 592m long and 31.8m wide.
The structure is being built on a new parallel alignment over a lake that has seasonal water level fluctuations of approximately 15m to 21m. Four form-travellers will be used in its construction.
The existing 405m-long concrete decked steel truss structure will be demolished and removed. The project is located in a high seismic area and incorporates complex earthquake resistant design details.
Finley is providing segmental bridge design and construction engineering services, including 3D time-dependent longitudinal superstructure analysis. Its role covers camber analysis, geometry control and construction manuals, provision of its geometry control software, post-tensioning calculations, temporary support falsework structures, shop drawings and design office support during construction.
Owner of the scheme is Caltrans and the contractor is Tutor-Saliba Corporation. Construction began in November 2009 and estimated completion is in 2014.
Box girder (1) |