SITUATION
An aging levee was in desperate need of repair as the storm drainage system had deteriorated due to age and the flood conditions that exist almost yearly along the Mississippi River. The levee was constructed to drain excess water from the local farmland into the Mississippi River and included a gatewell to stop a rising river from backwashing into the fields. The downstream lines ultimately drained into three exit pipes and into the river. Sections of the levee were in danger of failing during flood conditions and needed rehabilitation, but they couldn’t be taken out of service during the process. The general contractor that was awarded the levee rehab project, needed to find a non-disruptive structural solution that could fix the pipes in live flow (but non-flood) conditions.
CHALLENGE
The challenge for this project was to keep the system functioning while performing the work. Because of the flexibility of the SPR installation process, the levee drainage system was able to continue operating during the rehabilitation project. SAK started installing SPR in the upstream sections of the pipe and during the winding process diverted the flow among the three 84-in. corrugated metal drainage pipe sections until each 150-lf section was wound, bulkheads and bracing installed, and structural grouting commenced. The rotation of the work from line to line finished the repairs one by one and solved the problems for the levee.
The project was not without its issues. The flexible installation benefits of the SPR solution — a major reason it was selected — were leveraged twice during the project as the defiant Mississippi river flooded to back up the drain pipes.
SAK started installing SPR in the upstream sections of the pipe and during the winding process diverted the flow among the three 84-in. corrugated metal drainage pipe sections until each 150-lf section was wound, bulkheads and bracing installed, and structural grouting commenced.
This required the Levee District to close the gates within the structure, temporarily halting the project. Both times the project was stopped, the pipe section was only partially completed. Luckily, the SPR process could be interrupted because the waters from the river rose to top the pipes at levels fully submerging the downstream sections. Unlike other rehabilitation options considered for the situation, the SPR winding machine was simply removed and the lined pipes rode out the high water while the river was at flood stage.
SOLVED
Installation flexibility was a huge advantage. In this case, the ability to pull out the winding machine quickly was invaluable when informed of an approaching storm. Depending on the project removal times can vary, but in this case SAK was able to have the SPR winding machine removed in less than an hour.
