ASPIRE is a quarterly magazine published by PCI in cooperation with the associations of the National Concrete Bridge Council. The editorial content focuses on the latest technology and key issues in the Concrete Bridge Industry.
Issue link: http://www.aspiremagazinebyengineers.com/i/296997
Interstate 25 (I-25) serves as Colorado's major north-south freeway, extending from the Wyoming state line to New Mexico. The freeway weaves through the picturesque town of Trinidad, located at the base of Raton Pass and just north of the New Mexico state line. I-25 was carried through town on an aging viaduct consisting of a combination of steel and precast concrete girders spanning over a river, three existing rail lines, a future rail line, and four city streets. The girders were corded to meet the roadway's tight curves. Constructed in the mid-1950s, these bridges were nearing the end of their service life and required replacement. Preliminary design and environmental studies proved that realignment was not an option. The new structures needed to account for varying, highly skewed, substructure elements and complex horizontal geometry combined with reversing superelevated curves. The reconstruction of I-25 through Tr i n i d a d p r o v i d e d s o m e u n i q u e challenges. The remote small town of Trinidad is nearly 200 miles from any major bridge construction industry, has a limited supply of skilled labor, and only one local ready-mixed concrete supplier. B a s e d u p o n t h e s e c o n c e r n s , t h e Colorado Department of Transportation (CDOT) elected to include an option for alternate structural design types but maintained the requirement to adhere to strict aesthetic criteria developed during the preliminary design and environmental assessment. A local contractor and engineering firm teamed up to develop a prestressed concrete profile I-25 TrInIdad VIaducT / Trinidad, Colorado BRIDGE DESIGN ENGINEER: Tsiouvaras Simmons Holderness inc., Greenwood Village, Colo. PRIME CONTRACTOR: lawrence Construction, littleton, Colo. CAST-IN-PLACE CONCRETE SUPPLIER: leone Sand & Gravel & redi Mix Concrete, Trinidad, Colo. PRECASTER : Plum Creek Structures inc., littleton, Colo., a PCi-certified producer POST- TENSIONING CONTRACTOR: Schwager davis inc., San Jose, Calif. I-25 Trinidad Viaduct by Matthew Gilbert and Fred Holderness, Tsiouvaras Simmons Holderness Inc. Tight curves and variable depths challenge bridge designers 16 | aSPirE , Winter 2013 P R O J E C T I-25Trinidad_Win13.indd 16 12/28/12 11:43 AM