Heavy haul freight (silica mine), urban street by short line
100 track feet of crossing panels settled. This caused the adjacent asphalt pavement to fail, and caused tripping hazards at the adjacent pedestrian sidewalk. The crossing ran diagonally across the roadway. The crossing had been replaced twice in the past. The last replacement used flowable fill as the base material. Due to the urban, primarily passenger automobile traffic, there was little deflection of the crossing panels from highway traffic. However, there were up to four inches of deflection from rail traffic loading.
The deflection from rail traffic loading caused the top edges of adjacent panels to be in compression with each other. This caused extensive spalling of the surface, which affected approximately 8 panels. While not a functional problem for panel integrity, the spalled areas were within the sidewalk portion of the crossings, and therefore posed tripping hazards.
The repair had to allow immediate vehicular traffic to facilitate a single lane closure that was flipped halfway through the repair. The repair also had to allow for immediate resumption of rail traffic. The crossing served a sand mine, so repair was designed around high service loads for heavy haul rail traffic.
Due to scheduling constraints of the railroad, the repair method had to tolerate the potential for rail traffic during the repair.
CJGeo modular grade crossing repair crew filled the voids and corrected settlement in less than a day using polyurethane grouting. Asphalt patching was done concurrently with polyurethane injection. The entire repair was completed in less than one day. The roadway and rail opened up immediately after the repair. Traffic control was done to accommodate pedestrians and roadway traffic.
Two trains passed through the crossing over the panels being repaired during the repair. This did not affect the integrity of the repair.