This project consists of two pylons projecting vertically from the Missouri river bed with 20-ft.-deep footings. The lower portion of the pylon is 68 ft. high, 22 ft. 2 in. wide, and 129 ft. long projecting from the River in a Y configuration. The tower elevates to 402 ft. above the footing creating 22 lifts using automatic climbing systems SKE 100 and SKE 50 for all 4 Tower Legs.
MTA incorporated Doka’s D22 formwork for the lower portion of the pylon. This consisted of seven lifts with gangs being fabricated by the manufacturer for nearly every lift. The formwork and concept provided a working platform with ample space for the laborers to work from and an area to stage equipment. The forms were suspended on climbing shoes that encompassed the entire perimeter of both pylons.
MTA had to install a coffer dam and pump the Missouri river water out of the coffer dam to provide an area to pour footings. MTA used girder forms to form a 88x55x20 ft. footing.
Doka’s Heavy Duty Spindle Struts along with custom channels provided for maximum security when hanging forms from the pylon face. There were areas located at the eyebrow where the concrete face projected out at a 35-degree angle. The forms and concepts maximized efficiency and safety.
At both tower legs, a tie solution was converted to a tieless solution resulting in Doka designing and installing W16’s walers running vertically along back of the Top 50 gangs. Both SKE 100 and SKE 50 were incorporated for the Tower legs along with Framax Xlife forms for the interior core of the legs and Top 50 for the exterior. The SKE climbing systems offered MTA a method to cocoon working platforms and the ease of climbing all four legs without a crane.
Flexibility of the climbing system allowed for installation of wind protection screen to protect from harsh weather conditions during winter months. Specially designed formwork eliminated the need for ties in concrete and offered the contractor a tieless solution for onsite demands.
Flexibility of Doka’s climbing and formwork systems easily adapted to the bridge geometry and contractor’s requirements. Engineering support, know-how, and experience on previous and current bridge projects all over the globe, along with competitive pricing, reassured the contractor’s decision to go with Doka.