The structure has undergone some repairs and minor rehabilitations in the past, but has stood up well to the elements and extensive use.
Crews from The Ruhlin Company, based in Ohio, began work on the reconstructifon of Norfolk Southern Railway’s bridge in Michigan’s Monroe County last April and they are looking at completing the nearly $10 million project in May 2015.
The 450 ft. (137 m) bridge (single track), built in 1887, spans the Raisin River. The structure has undergone some repairs and minor rehabilitations in the past, but has stood up well to the elements and extensive use.
“It’s in fair condition,” said Ben Neal, Ruhlin’s project superintendent, “but it’s old and starting to deteriorate to the point where it needs to be replaced. The original builders knew what they were doing. It’s lasted over 100 years and they did a good job with the construction materials and equipment that they had at the time.”
The existing bridge is being maintained while crews will build a new substructure (with reinforced concrete) beneath it. A new superstructure with a metal deck shall be built in a nearby laydown yard.
“The owner will allow us a certain amount of time, which has not been determined yet,” said Neal, “to change the bridge deck out. The elevation of the bridge will not change.”
Neal has managed many railway bridge projects. When the current bridge is demolished, it will yield nearly 1.5 million lbs. (680,389 kg) of steel, 319 cu. yd. (244 cu m) of concrete, and 150 cu. yd. 115 cu m) of masonry. Much of the material will be recycled.
The depth of the river below the bridge is approximately 3.5 ft. (1 m). Three coffer dams (about 10 ft. [3 m] deep) are being placed in the middle of the river so that micropiles can be drilled into the riverbed at depths of between 30 to 40 ft. (9 to 12 m).
“Setting up the coffer dams underneath an existing bridge is a difficult process,” said Neal. “The low headroom under the existing bridge made driving sheets difficult. We utilized our Movax attachment on a Catepillar excavator to drive the sheets from a stone causeway installed across the river to access the new pier locations.”
The dams should be ready by November, which will allow Spartan Specialties to install the micropiles, which then allow the substructure work to begin. Currently Ruhlin has eight personnel on site, but that should rise to between 25 and 40 at the peak of the project.
“We’ll be working right through the winter,” said Neal. Cold temperatures slow everything down. It is tough on the workforce as well as the equipment. Tasks such as pouring concrete require protection from the cold temperatures for the new concrete to cure.”
Permits from the Department of Environmental Quality were secured to allow the construction operations to proceed.
“Temporary bridges were built within the causeway to maintain the flow of the river as well as provide passage for fish,” said Neal. “Our environmental permits also mandate the a barrier be placed on the river bottom to separate the temporary stone causeway from the riverbed.”
The substructure is expected to be completed by January, 2015 and should consist of 625 cu. yd. (478 cu m) of concrete and 30 tons (27 t) of rebar. The new bridge superstructure will consist of 700 tons (635 t) of steel.
“Material deliveries are accepted as we need them,” said Neal. “An open lot on the southwest corner of the bridge is being used for a lay down yard as well as provide space for an office trailer and employee parking. The area has been fairly secure. A gate was installed along our access road to prevent unauthorized vehicles from using the railroad crossing installed for project use. Upon completion of the job, the crossing will be removed.”
In terms of equipment and vehicles, currently on site there is a Cat D6 dozer, Cat 330D and 308 excavators, and a Volvo 120F loader. The drill rig for the micropiles, a Hutte 202, is being brought in by the subcontractor. The Grove 6300L 350 ton (316 t) all terrain and a Liebherr LTM1220-5.2 265 ton (240 t) all terrain crane will be on site in early December to help construct the steel portion of the new bridge.
When vehicles and equipment break down or require routine maintenance, mechanics are brought in from the company’s main yard in Sharon Center or from the local Caterpillar dealership. The Cat 308 excavator is being rented from the Ohio CAT dealership in Perrysburg.
The equipment is being monitored electronically by staff at Ruhlin’s yard and by the operators, which gives Neal a good handle on the state of the equipment.
“There are very few surprises and the main problem that arises is leaks in the hydraulic lines and the need to replace them rapidly,” he said. “While they cannot be anticipated, most of the time, the lines can be replaced in quickly.”
Neal pointed out that while this project has many typical elements, the demolition of the bridge deck and its quick replacement to minimize the closure of the railway line will require detailed planning.
“The existing bridge will be cut apart in place and loaded out onto trucks and dumpsters to be sent to the scrap yard,” he said. “The new bridge will be placed onto the newly constructed substructure using six line goldhofers supplied by Selinsky Force LLC. Details of the replacement are currently being worked out. Key personnel will plan each part of the work that must take place during the outage. Completing the work required during the outage timely is critical to the success of the project. ”
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