Michigan Department of Transportation
Location: Ada, MI
Contract Value: $12.8 million
Hardman Construction is currently working on the M-21 bridge project in Ada, Michigan. The M-21 bridge over the Grand River is a $12.8 million dollar project. The owner is the Michigan Department of Transportation - MDOT. Numerous bridge projects require the installation of extensive amounts of driven H-pile and steel sheeting, especially those constructed over water. and the M-21 bridge project is no exception. The project includes the removal of the existing bridge, construction of the new structure and the construction of a 1,400 LF temporary bridge. The temporary bridge was built to carry trac during the removal and replacement phases of work. The former bridge was a 500' long, seven-span structure that carried four lanes of trac. The new structure is a 500' long, 6-span bridge that will carry four lanes of trac plus a 12' wide bicycle/pedestrian lane. The temporary bridge had to be constructed over the adjacent flood plains, which increased the total length to 1,400 LF. The temporary bridge was one of the longest temporary bridges constructed for an MDOT proejct. The temporary bridge portion of the project was constructed under a design build item, and all design and construction was performed by Hardman Construction. The design that proved to be the most economical to construct was a simple supported steel beam bridge bearing on a driven pile pier cap. The temporary bridge is a 27-span structure. The driven piles utilized for the temporary bridge were 16" High Capacity H-Piles - HP16*162 that were driven up to 1,100 KIPS. The piles were driven initially with a vibratory pile hammer, and then nal driving was performed with a Delmag D36-42 diesel pile hammer. Pile capacities were veried through the PDA testing method. The removal of the former structure required six coerdams to be constructed to isolate the removal activities from the river. The new bridge required seven cofferdams to be installed, five for the piers and two for the abutments. The pier cofferdams were 118' long x 13' wide and the excavation depths were 30' below the existing river. The proposed bridge was supported by driven H-piles. The H-piles were HP 14*117 and had capacities of 600 KIPS. In total, more than 100,000 square feet of steel sheeting was installed for the project and more than 400 driven H-piles. The project started in 2010 and will be complete in 2012.