Old Monroe Railway Bridge
- LocationOld Monroe , Missouri
- TimelineSeptember 2019 - January 2020
Michels Foundations was contracted to install drilled shafts to support a newly constructed replacement bridge for a Railway Company in Old Monroe, MO. The new bridge will replace the current 374' Pratt Through Truss bridge constructed in 1901, which spans the Cuivre River.
Michels originally planned on installing the drilled shafts with a single drill rig, however the Client's project was delayed due to flooding on the Cuivre River. Michels proposed mobilizing a second drill rig to accelerate the schedule, our Client agreed, and the 8 drilled shafts were constructed utilizing two Liebherr LB36 drill rigs.
The shafts were 66 inches in diameter and included full length permanent casing which was installed with an oscillator. The drilled shafts varied in lengths from 85 to 123 feet, including rock sockets with depths ranging from 11 to 22 feet. The drill rigs worked off of temporary trestle work bridges engineered to handle the weight of the drill rig and additional construction equipment.
Drilling fluid was carefully handled to protect the waterway that flows into the Mississippi River. The karst limestone conditions encountered were caverns within the bedrock below the bottom of river grade. This was an unforeseen condition that required an alternative drilled shaft design to achieve the capacity required to support the bridge. The alternative design included shortening the drilled shaft lengths and adding micro piles inside the drilled shaft.