NY Grade Crossing Repair
The Job
10 panels of StarTrack modular grade crossing tubs settled in an urban street crossing owned by a short line. As a result of the settlement multiple clips broke. This caused the panels to pump.
The Challenge
The crossing tubs settled, and when crossed by trucks, pumped water containing the sub-ballast up between the tubs and adjacent pavement. The adjacent track also settled significantly.
The Solution
CJGeo proposed grouting immediately below the panels, and also into the underlying disturbed subballast using CJGrout 48NHL geotechnical polyurethane grout.
The CJGrout 48NHL was injected through 5/8″ holes drilled through the panels. The settlement pattern of each panel determines the specific hole spacing. It takes about five minutes for the grout to cure to 95% of its ultimate strength.
CJGeo performed the StarTrack modular grade crossing repair without impacting rail traffic. The facility was able to function normally throughout the repair, which took less than a day.
New York Tub Crossing Lifting
The Job
Eight panels of StarTrack modular grade crossing tubs settled. As a result of the settlement multiple clips broke.
The Challenge
The crossing tubs settled, and when crossed by trucks, pumped water containing the subballast up between the tubs and adjacent pavement. The crossing was the only entrance into an industrial facility that took two trains per day. Because of limited onsite storage, rail service couldn’t be disrupted at all.
The Solution
CJGeo proposed grouting immediately below the panels, and also into the underlying disturbed subballast using CJGrout 48NHL geotechnical polyurethane grout. CJGeo performed the grouting without impacting rail traffic, and the facility was able to function normally throughout the repair, which took less than a day.
Willow Springs Crossings
The Job
BNSF’s Willow Springs Intermodal yard is a critical facility in United States’ freight rail network. The facility is colocated with a large UPS trucking operation, and BNSF has very tight time lines for transferring containers from inbound trains to UPS.
The Challenge
80 StarTrack modular grade crossing panels across 10 different crossings in the facility experienced settlement. The settlement was affecting the safe operation of yard trucks, causing delays in container transfer times.
Because of the 24/7/365 operation, and very tight performance times, there was no tolerance for downtime.
The Solution
CJGeo proposed grouting the affected panels with CJGrout-48NHL. 48NHL is specially formulated for differential settlement correction in high load applications, such as heavy haul rail.
CJGeo mobilized a polyurethane grouting crew with extensive modular grade crossing repair experience and grouted the 10 crossings over a period of five days onsite. The grouting was done without affecting rail traffic, yard truck operations, or performance metrics.
New Jersey Grade Crossing Stabilization
The Job
A precast modular grade crossing (Oldcastle StarTrack) crossing developed significant pavement deterioration. NJDOT directed the railroad to stabilize and lift the panels and then patch the adjacent asphalt.
The Challenge
The grade crossing sees up to 8 trains per day (heavy industrial service), and crosses a four lane arterial highway. So, there wasn’t any allowable downtime.
The Solution
CJGeo proposed grouting the panels using CJGrout 60NHL. 60NHL is a geotechnical polyurethane grout specifically formulated for heavy applications such as rail and aircraft loads. A CJGeo polyurethane grouting crew mobilized to the site and in fewer than 2 hours onsite restored the affected panels.
66″ Water Main Abandonment
The Job
The Purple Line is a light rail line project in suburban Maryland designed to increase connectivity within Maryland’s suburbs of Washington, DC. The project involves extensive utility relocation to facilitate installation of large embankments and the extensive infrastructure required for a double track rail corridor dropped into the middle of an already exceptionally congested/dense corridor.
The Challenge
As part of the project, a large MSE wall needed to be installed over approximately 3000LF of 66″ PCCP water main. In order to avoid any future maintenance problems under the rail alignment, a new line was installed adjacent to the embankment, and the old line needed to be abandoned.
Due to construction sequencing, the embankment was already in place well before the water line relocation was performed.
The Solution
CJGeo worked with the utility relocation contractor to design a grout mix and grouting program that provided sufficient bearing capacity to eliminate concerns about future stability. The ultimate design for the mix was a 100psi cellular grout. Given that the embankment was already in place, the entire 3000LF stretch had to be grouted from just two access points.
CJGeo used a 200CY/hour dry mix batch plant onsite to generate and pump the cellular concrete up to 1500LF to place the material. 2800CY of material were placed over a period of four days onsite with no disruptions to adjacent construction activities.
North Carolina Tub Crossing Repairs
The Job
Fifty two OldCastle StarTrack panels at four different grade crossings settled to the point of requiring slow orders at the crossings. In order to restore the track to normal speeds, the settlement needed to be corrected.
The Challenge
Due to scheduling constraints with rail traffic, with very short windows on weekend nights, the owner elected to have the repairs completed during a single weekend shutdown period. While this allowed for longer work periods, it also meant that four crossings needed to be repaired in fewer than 24 hours.
The Solution
CJGeo mobilized two polyurethane grouting crews to the system, and grouted two crossings each during two shifts. All 52 of the panels were stabilized and lifted back to grade using CJGrout 60NHL, which allows for immediate resumption of rail traffic, from light rail to heavy haul.
Rail Bridge Pier Stabilization
The Job
This project was a capital repair to a bridge pier for a Class I railroad serving the Port of Charleston, SC.
The Challenge
The Congaree River south east of Columbia, South Carolina frequently sees high flow events, inundating the surrounding low country. At the transition from timber trestle to a bridge, the first bridge pier was originally constructed of stone, bearing on a timber pile supported timber mat. Over time, the river channel migrated and began to expose the timber substructure and scour below the pier.
The nearest road was more than four miles away through impassible swamp, so all work had to be performed from the river, and all material had to be pumped across the bridge, a distance of approximately 600 feet. Due to the compressive nature of the underlying materials, any backfill material needed to be as light as possible, but due to the high likelihood of flooding, couldn’t contribute significant potential uplift.
The Solution
To address the scour, minimize additional load to the underlying soils, and ensure long term stability of the structure, a third party consultant designed a two tier sheet pile jacket for the structure, and specified the backfill material as 65lb/cuft cellular concrete for the lower segment, and approximately 45lb/cuft cellular concrete for the upper segment.
CJGeo designed mixes which would meet these requirements, be pumpable 600LF, tolerate the high vibration environment from the more than 12 trains per day, and facilitate a short installation timeframe.
After the general contractor installed the first level of sheet piling and dewatered the area, CJGeo placed approximately 150CY of 65lb/cuft material. The second, smaller diameter, ring of steel was installed, and CJGeo then filled the annular space between it and the necked down pier with 45lb/cuft material.
The cellular concrete was installed over a period of four days onsite.
MSE Wall Backfill
The Job
The geotechnical investigation for a double bridge replacement in Amelia County, Virginia found a layer of compressible soils below four proposed abutments.
Anticipated settlement exceeded allowable settlement, so the abutments were designed to be backfilled with expanded shale lightweight aggregate.
The two parallel bridges have an AAWDT of 14,000 and carry a rural divided highway (US-360) over Norfolk Southern Railway & Business 360 in Amelia Courthouse, Virginia.
The Challenge
Lightweight fill placement had to be unaffected by frequent rail traffic, have a limited footprint, and be economical.
The Solution
CJGeo provided a value engineering proposal to utilize 30lb/cuft cellular concrete in place of the expanded shale lightweight aggregate. This significantly reduced the unit weight of the lightweight fill, given the 70lb/cuft density used in the design, further reducing the anticipated settlement.
CJGeo mobilized a 200CY/hour cellular grout plant to the site and placed lifts ranging in size from 35 to 300CY. Wall erection crews were able to walk on the in-place cellular concrete without leaving footprints as quickly as 4 hours after each placement.
The total project volume was approximately 7200CY.
Coal Pier Sinkhole Grouting
The Job
With an annual throughput capacity of 48 million tons, Norfolk Southern’s Pier 6 at Lamberts Point in Norfolk, Virginia is one of the largest coal trans-loading facilities in the world. As an around-the-clock facility built around precision logistics, there’s little tolerance for disruption or downtime.
The Challenge
When two sinkholes opened up at the end of Pier 6 adjacent to the bulkhead, railroad personnel reached out to an onsite maintenance contractor. Steel plates were installed to provide temporary protection while a long-term solution could be implemented.
The Solution
CJGeo performed DCP testing at the site in order to quantify the depth of voids below the pavement adjacent to the sinkholes. The DCP testing showed that in addition to large voids visible from the sinkholes immediately below the pavement, there were large pockets of voids down to 15’ below the surface.
CJGeo crews then used CJGrout 35NHV61, a hydro insensitive, NSF-certified geotechnical polyurethane to fill all voids and restore stability to the area. The grouting work took five hours onsite to install 3400 pounds of material, with zero disruption to operations.
Tub Crossing Repair
The Job
The sandy soils of South Jersey are great for growing produce and mining pure silica sand. While most of the produce is shipped by truck, a lot of the silica is shipped by rail. The rails inevitably cross the roads, and many of the crossings are at grade.
The Challenge
A short-line railroad was experiencing significant settlement and pumping of multiple precast modular crossings in the Vineland & Millville areas. Each crossing saw significant truck traffic, primarily from aggregate mining, and also significant heavy haul rail traffic from transporting sand.
The Solution
Working with a rail maintenance contractor, CJGeo performed polyurethane grouting on a total of four precast tub crossings in the area. Each was done in a single day, with the immediate resumption of automobile traffic, and rail traffic. Supplemental bolting was performed to address the deterioration of the panels that had resulted from the extensive movement of the panels.
