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/306183
The new U.S. 191 Bridge over the Colorado River in Moab, Utah, blends with the spectacular Canyonlands region and offers a number of features to ensure that the landscape remained pristine during and after construction. The state's first segmental concrete bridge was constructed in a way that allowed continual recreational use of the river and surrounding area during construction. Long spans ensured a minimal bridge footprint, while a unique public involvement process provided a context-sensitive design representative of the community's vision. The pristine environment surrounding M o a b w a s a c k n o w l e d g e d i n t h e solution by the Utah Department of Transportation (UDOT) and Figg Bridge Engineers. The twin, 1022-ft-long bridges consist of cast-in-place, post- tensioned concrete segmental structures built from above using the balanced cantilever method of construction to protect the environment. Piers and abutments were staggered 38 ft to align the substructure with the river- flow direction, which is skewed to the roadway alignment. The bridges are 39 ft 10 in. wide including two 12-ft-wide lanes, a 7-ft-wide outside shoulder and a 6-ft-wide inside shoulder. Pedestrians, mountain bikers, and casual riders are separated from the highway traffic by using a new pedestrian bridge upstream. Unique Site Characteristics The bridge is in one of the most high- profile locations in the region, drawing more than 1.5 million visitors a year to its picturesque landscapes. It provides a gateway to Arches National Park, Canyonlands National Park, Dead Horse Point State Park, and the Sand Flats Recreation Area. Designated wetlands along the south bank required careful consideration. In addition, water levels in the river can vary greatly, historically causing flooding of the Moab Valley. Flows in excess of 100,000 ft 3 /sec have been recorded at the bridge site. The design had to accommodate seasonal variations in water-surface elevation of more than 15 ft. A site- specific hydraulic analysis completed for the project ensures that the new bridge profile COLORADO RIVER BRIDGE / MOAB, UTAH EngI nEER : Figg Bridge Engineers, Denver, Colo. COnSTRUCTIOn EngInEERIng AnD InSpECTIOn: Figg Bridge Engineers, Denver, Colo. R OADwAy EngInEERS: Lochner, Salt Lake City, Utah SURVEy, ROw, AnD gEOTEChnICAL EngInEERIng: RB&G Engineering, Provo, Utah pRIME COnTRACTOR: Wadsworth Brothers Construction, Draper, Utah COnCRETE SUppLIER: Legrand Johnson, Moab, Utah pOST-TEnSIOnIng COnTRACTOR: DyWIDAG-Systems International USA Inc., Bolingbrook, Ill. by Fred Doehring, Utah Department of Transportation and Stephen E. Fultz, Figg Bridge Engineers In Harmony with Nature Utah's first segmental bridge constructed from above to minimize impact on scenic national park Construction was completed in December 2010, on the U.S. 191 Colorado River Bridge in Moab, Utah, the state's first concrete segmental bridge. The bridge's sustainable design kept the focus on the natural wonder of the environment. All photos: ©Figg Bridge Engineers. 14 | ASPIRE , Spring 2011 P R O J E C T Book_Spr11.indb 14 3/30/11 5:09 PM