MoDOT leaders provide update on Long Branch Bridge project

The reconstruction of the Long Branch Bridge, located on Highway 136, east of Maryville, has hit several snags early in the project.

“We understand that the closure of US Route 136 for the Long Branch Bridge reconstruction project was unexpected and has caused some frustration and confusion, particularly regarding the construction timeline,” noted a MoDOT update report.

The report continued by stating that the original plan for the reconstruction of the multi-span bridge was to close to traffic only half of the structure at a time. There were plans for a signal light to guide motorists through the work zone.

“This was done in an effort to continue to reduce impacts to local, visiting and agricultural traffic,” said the report.

Construction on Long Branch began May 2, and structural issues in the bridge girders were discovered on May 11, which created an unsafe condition for motorists. The bridge was immediately closed to all traffic.

The bridge over Long Branch has twice as many supporting structures, and with the design and the contractor schedule set to build it half a time, some parts of the process cannot be expedited. There may be some timesaving measures the contractor can take to get the bridge reopened earlier, but it will not cut the construction time in half. Construction of a typical small bridge, under a full closure, averages approximately 90 to 100 days. MoDOT engineers and inspectors are working with the contractor towards meeting that goal, however time has already been lost trying to construct it in two stages.

In addition to inclement weather, there are certain times during construction when crews may not be on site or may not be visible to motorists. Portions of the bridge may need to cure for several hours or days to build strength before workers can proceed with the next step in construction, or crews may be working under the bridge, out-of-sight to drivers.

The contractor began driving pile on May 31. The contractor, Phillips Hardy, has had some issues driving the piling. The pile foundations to be installed in the middle foundations are larger cast-in-place concrete structures. The steel pipe piles are 20 inches in diameter, are heavier than the 16 inch diameter piles on the end abutments and have a higher load requirement than the abutments.

Because of this, the contractor has to use a larger, about 50,000 pound, pile hammer to drive them. They have had issues setting up this larger pile hammer, but were able to drive the first four piles down to bearing late last week. They started to drive piles on the west abutment as well and weld on the extensions. The piles are 50 feet long per section, and the total length in place is about 98 feet estimated, so it requires welding two pieces together. After the pile driving the contractor confirms the work has the required load bearing. If all goes well, the contractor will be able to complete driving the piles and continue with the concrete pour by mid-June.

“Work will move faster and be more consistent once the foundations are completed,” concluded the report.

The planned project completion is still expected for August 2022.