modular grade crossing repair using polyurethane grouting

Maryland Grade Crossing Repair

Maryland Grade Crossing Repair

Crossing Use:  

Light rail, suburban streets

Problem:

Three crossings (two doubles and a single) totaling approximately 400 linear feet were experiencing pumping up to 2 inches, and settlement up to 3 inches. The crossings were all on the same line of a light rail system. Two crossings were at major intersections, and a third crossed the entrance to a manufacturing facility.

In addition to the settlement and pumping, significant water-filled voids were present below the precast modular grade crossing panels. All three of the precast crossings were constructed of Premier panels.

Constraints:

During the injection work, it became apparent that some of the anchor bolts holding together the modular crossing panels had failed. To facilitate timely repair, a retrofit anchor bolt system was installed simultaneously with lifting repairs. The crossings had been in place for 16 years, and one had been previously repaired using mud jacking.

Solution:

High density polyurethane grouting to stabilize and lift the affected precast grade crossing panels. Foam jacking is superior to mud jacking (grout injection) for repairing grade crossings because the repair itself is much faster, and allows for immediate resumption of traffic.

Result:

 CJGeo lifted and stabilized 50 panels over two night time work shifts. Work was completed between 1am and 8am to avoid any disruptions to normally-scheduled passenger rail traffic. This grade crossing repair was completed on budget, on schedule, and with much less disruption than associated with mud jacking.