Quarry Modular Grade Crossing Repair

Quarry Grade Crossing Repair–Frederick, Maryland

Crossing Use:  

Heavy haul freight & passenger, mining haul road

Problem:

Settlement and deflection were affecting a four-panel Premier Modular Grade Crossing.  The crossing served a spoils haul road for a quarry, and was used by both CSX and commuter rail.  

Settlement of modular grade crossing was causing spalling of the panel edges due to more than 3 inches of deflection from both rail and quarry truck traffic.  The ballast of the adjacent track was also fouled, which caused the voids under the panels to hold water, which worsened the situation.

Constraints:

Modular grade crossing repair in Frederick, Maryland using polyurethane grouting to fill voids and correct settement

Modular grade crossing repair.

The repair had to quickly and thoroughly address the voids and settlement of the panels to avoid disruption to commuter revenue traffic.  A daily window of four hours between last morning and first afternoon commuter traffic was available for the repair.  

Due to scheduling constraints within the busy Washington, DC metro area freight market, the repair area had to be openable to freight traffic on 15 minute notice any time during the repair. 

Additionally, the material use for void filling and lifting needed to be resilient under dynamic loading from train and heavy truck traffic, and capable of performing well in saturated environments due to poor drainage infrastructure in the area.

Solution:

High density polyurethane polyurethane grouting to stabilize and lift the affected precast grade crossing panels.  

Polyurethane grouting is an effective repair for both void filling to address deflection, and also lifting panels to correct settlement.

Result:

CJGeo modular grade crossing repair crew filled the voids and corrected settlement in fewer than four hours.  During the repair, a CSX freight train passed through the work area twice, without disrupting the integrity of the repair.  

Tamping of adjacent track was performed simultaneously by others.  The crossing was returned to service without disruption to commuter rail service.