Featuring approximately 35,500 square feet of Doka’s pre-assembled Top 50 gang formwork, the US 460 Connector twin segmental box bridge was built to improve local and regional connectivity and improve the coalfields expressway infrastructure. Located in Breaks, Va., the new connector is the tallest bridge in Virginia. The owner wanted an innovative solution for the project. As such, Doka was hired by CJ Mahan Construction Company to meet the challenge.
Design
The project design called for six Pier Tables for the eastbound and westbound lanes at a length of 50’-0” long, 43’-4” wide and 30’-4” tall each, placed in three lifts. The Pier Tables were designed with three horizontal construction joints with an initial base slab with an 8’-0” tall wall pour for the first lift. The second lift required elevated support and a drive deck with inverted wall pour was needed for lift three. Doka designed the formwork for the first lift with an overhead gantry-style system to hang the formwork allowing the base and slab walls to be placed in the same pour. In addition, the 1,733-foot-long, 250-foot-tall twin segmental box bridge had varying depths from 31’-0” to 12’-6” and each span had thirteen segments cast 16’-6” each. Doka designed the formwork to be used with VSL’s form traveler system.Pre-assembly
All Top 50 gang formwork used to form the Pier Tables and the traveler forms on the balanced cantilever concrete bridge was pre-assembled by Doka in their pre-assembly facility in Channahon, IL. Nearly 20,036 square feet of pre-assembled Top 50 gang formwork was used to build six sets for Pier Table lift 1, 2 and 3, and 15,340 square feet with custom stiffbacks and components were used to build four sets of traveler forms for the VSL form traveler.Doka’s experienced staff conducted an equipment audit on all custom equipment on site to guarantee accuracy for the customer. This prevented any setbacks for the contractor and allowed the traveler to be assembled efficiently, thus saving time on the job. Further, Doka worked with the customer to determine where the walkway platforms needed to be designed ensuring safety on the jobsite.
The US 460 Connector Bridge project helped stimulate the economy and coal synergy for the local community. Further, improvements to the coalfield expressway infrastructure system were accomplished with the help of Doka’s formwork solutions.
