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By applying unique solutions to increase the safety and longevity of our environment.

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.

Garden State Parkway grouting

The Job

As part of ongoing large diameter culvert rehabilitations and replacements, four new bored stormwater crossings and the original culvert they replaced needed to be grouted. The tunnels ranged from 120″ down to 74″, for a total of 312CY, and the abandonment required 405CY.

The Challenge

Grout needed to meet the minimum strength requirements of the owner, and ideally needed to be light enough to facilitate single lift annular space grouting.

The Solution

CJGeo’s preconstruction team worked with the general contractor to design a grouting program which facilitated single lift abandonment of the original culvert, and single lift grouting of the four various annular space runs. CJGeo utilized onsite dry batching to generate 30lb/cuft CJFill cellular concrete.

Lightweight Plaza Fill

The Job

Lightweight plaza fill for a private age restricted high rise new build in Tysons Corner, Virginia.

The Challenge

To manage dead loads over the four story parking deck, while achieving a landscape design requiring up to five feet of fill, the designer specified 20lb/cuft cellular concrete for the plaza fill material. The material had to be permeable, and placed up to 600′ from the closest access point for a plant.

The Solution

CJGeo mobilized a 200CY/hour dry batch plant and crew, who generated up to 500CY/day for placement via hoses and a boom pump to successfully fill the plaza areas. Total project volume was approximately 2200CY.

CBBT Pregrouting

The Job

The Chesapeake Bay Bridge Tunnel’s Parallel Thimble Shoal Tunnel Project is constructing a second tunnel parallel to the original to reduce traffic congestion. All work is being performed from man-made islands in the Chesapeake Bay which are densely packed with utilities, equipment and operations facilities associated with the existing tunnel, which is in continuous use.

The Challenge

During previous phases, installation of sheet piling for tunneling activities and other driven elements induced consolidation of the loose sandy fill on the islands, causing settlement of duct banks, pavements and other structures, which were remedied by CJGeo using polyurethane compaction grouting.

In this case, sheet piles had to be driven immediately adjacent to the roadway in order to excavate the receiving pit for the tunnel boring machine. The construction team was concerned about inducing settlement of the adjacent roadway, so reached out to CJGeo about performing compaction grouting under the footing for the original tunnel’s portal wall, after the wall had been demolished down to grade.

The Solution

CJGeo performed compaction grouting utilizing an NSF-certified potable water contact plural component polyurethane grout. Cutoff criteria was 0.10 inches of movement of the foundation or adjacent roadway. Upon completion of the compaction grouting by CJGeo, sheet piling installation started, with only nominal movement of the foundation and roadway.

Hollow Abutment Filling

The Job

As part of a bridge rehabilitation for MassDOT, two hollow abutments needed to be filled in order to turn the structural approach/departure slabs into slab on grade.

The Challenge

It was up to 30′ from the bottom of slab to the underlying soil which had originally been installed to backfill the abutments. In order to reduce the loads applied to the bridge from the backfill, the lightest possible material capable of providing sufficient support to the pavement was required.

Due to integrated beams for the structural slabs, there were 12 different individual pockets which were up to 2′ tall, which had to be vented independently during the final lift, 4 of which had to be under live traffic because the road couldn’t be completely closed.

The Solution

CJGeo worked with the general contractor to formulate a plan to vent the individual pockets from outside of the open lanes, to ensure a complete fill without requiring a complete road closure. Over the course of two mobilizations, CJGeo placed 2,840CY of 25lb/cuft cellular concrete to fill the abutments.

8″ Pipe Abandonment

The Job

As part of continuing waterline replacements, a utility contractor in Fort Washington, Maryland, needed to abandon 10,600LF of 8″ water main. The utility and DOT both require grouting of all utilities 6″ and larger taken out of service.

The Challenge

In order to minimize the number of placement points, the grout needed to be exceptionally mobile.

The Solution

CJGeo proposed a 30lb/cuft cellular grout, and worked with the client to design a grouting plan that would allow grouting all 10,600LF of pipe from just three access points. CJGeo performed the grouting over a period of two days, with no additional excavation required from the customer other than their original tie ins/disconnects.

Union County Annular Space Grouting

The Job

Due to a rapidly increasing population, Union County, North Carolina installed a new raw water intake, which required a nearly 11 mile long raw water line to supply a water treatment plant.

The Challenge

While there were dozens of open cut road crossings along the alignment, 17 crossings were bored, and require annular space grouting per NCDOT requirements. Given the length of the project, there weren’t any ready mix providers who could cover the entire project.

The Solution

CJGeo has multiple NCDOT approved mix designs, CJGeo was able to source material from two different ready mix providers, and grout the annular space on each crossing per NCDOT requirements.

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.

Spillway Bridge Grouting

The Job

Two DOT-maintained bridges crossing two privately owned dam spillways had to be closed because of extensive undermining of the spillways. The undermining was allowing nearly all of the flow to happen below the spillway slabs, which caused large sinkholes to form adjacent to and under the roadway pavement, and also led to some settlement of the spillway slabs.

The Challenge

There was very little room to work–just under 4′ of clearance below the bridge beams. Also, the velocity of the water through the voids below the structure was quite high.

The Solution

CJGeo proposed a combination of plural component polyurethane grouting to address the water flows and voids, and hydrophobic chemical grout placed directly into cracks. A single CJGeo grouting crew was able to complete the repairs in a day (roughly 2500sqft of work, and approximately 4500lbs of polyurethane, plus 30 gallons of hydrophobic chemical grout). Dye testing during and after the grouting work confirmed that no more leaks were present under or around the spillway structures.

24″ Water Main Abandonment

The Job

As part of a large transportation project, 2000 linear feet of 24″ water main needed to be relocated out of a highway right-of-way.

The Challenge

Due to phasing, the old water main was located under the existing roadway and could not be accessed, except for at one point near the center of the run. So, the abandonment grout had to meet VDOT’s minimum strength requirements for flowable fill, and be pumpable up to 1100LF at low pressure.

The Solution

CJGeo grouted each run of pipe using 30lb/cuft cellular concrete. Each placement took fewer than two hours, and required no additional traffic control, disruptions to other construction activities, or help from the utility contractor after they installed the bulkheads.

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