By: Contech Engineered Solutions
Norfolk Southern (NS) Railway operates an east /west line through suburban Philadelphia, Pennsylvania. Bridge MV 25.13 is a seven-cell stone arch structure that has been in service for approximately 150 years.
Several different rehabilitation efforts have been employed over the life of the bridge. The most recent challenge was to find a method and/or product that would be able to repair and reinforce the 50′ span, single radius arches yet allow the rail line to remain in operation while the repairs were made.
The consultant concluded that 4 of the 7 cells would require the additional work to avoid further deterioration and possible track closure. A feasibility study found the most cost-effective method was to slip line the arches with corrugated structural plate.
After evaluating the existing conditions, Contech Engineered Solutions recommended its deep corrugation 15″ x 5 ½” structural plate product for the reline of the existing culvert arches and to meet the large span and heavy loading requirements.
The design method utilized allows for the full transfer of the railroad live loads to the new arch and subsequently to the grouted annulus and the reinforced concrete footings.
Once each arch was completely assembled, a flowable cementitious grout mixture was pumped into the existing void between the two structures.
After the curing process, the result was a completely rehabilitated structure. The reline of the four arches was completed without any interruption to rail operations.