Banner

Projects

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

Virginia Polyurethane Grouting

The Job

This Virginia polyurethane grouting project is located in Blacksburg, Virginia, at Virginia Tech. The work was done to support continued occupancy of the structure, after voids as deep as two feet were located below the floor slab.

The Challenge

A small area of the ground floor slab on grade settled, primarily adjacent to the basement, which is only under about 20% of the building footprint. The basement contains mechanical equipment, and ties to a large crawlspace used as a ventilation duct.

Upon initial discovery, the university’s on-call geotechnical and building envelope consultant performed exploratory drilling to determine the extent of voids. Several auger bores for exploration of the backfill material identified poor control during installation as the most probable cause of settlement.

The Solution

CJGeo was the most responsive bidder on the owner’s solicitation, which called for filling the voids below the floor with CJGrout 20SDB geotechnical polyurethane. 20SDB is specifically formulated for maximum expansion, high mobility, and very low exotherm.

One particular challenge was the amount of glass gravity drain piping below the floor. Because much of the building is lab space, when it was built, the most chemical-tolerant pipe available was glass. So, it was very important that the polyurethane grouting work not damage the relatively fragile pipes.

CJGeo timed its work around spring break to avoid any disruption to classes, research, and offices. The work took six days onsite, and a total of just under 10,000 pounds of CJGrout 20SDB.

Speak With An Expert

Facing a similar challenge to this Virginia polyurethane grouting project? Give us a shout or shoot us a text. Click the state marker for the location of your project for contact info for the appropriate rep.

Electric Bore Annular Space Grouting

The Job

This electric bore annular space grouting project is located in Norfolk, Virginia. As part of significant work at the Port of Virginia’s Norfolk International Terminal, an electrical contractor installed seven jack & bore crossings of various roadways and railroad lines within the port.

The Challenge

There are seven bores, ranging from 85 feet to 362 feet. Each bore is 36″ steel casing, with eight, eight inch conduits. Most conduits are for electrical lines, some are reserve, and some are for communication and data.

The designer’s specification call for annular grouting of all the conduits, with a minimum 1000psi grout. There was no thermal conductivity requirement.

The Solution

CJGeo proposed a 60lb/cuft CJFill-Standard cellular grout in order to meet the 1000psi requirement. Buoyancy control was achieved through water filling of the conduits, along with a conduit & casing spacer design which presumed some buoyancy.

The customer filled each of the conduits with water prior to grouting. Due to the relatively low volume of grout per bore (ranging between 16 & 57 cubic yards), CJGeo used a local ready mix supplier for paste, and the wet batch generation method. CJGeo successfully performed the electric bore annular space grouting work over two days.

Speak With An Expert

Facing a similar challenge to this electric bore annular space grouting project? Give us a shout or shoot us a text. Click the state marker for the location of your project for contact info for the appropriate rep.

Railroad Bore Annular Space Grouting

The Job

This railroad bore annular space grouting project is located in Winchester, Virginia. As part of a new development, three parallel stormwater pipes were bored under a CSX right of way.

The Challenge

The railroad requirements include annular space grouting. The three casings (80 feet long each), are 48″ by 0.725 wall thickness steel. The carrier pipes are 30″ N-12 pipe, with a 35.50″ outside diameter.

This annulus requires about 16 cubic yards of grout per bore. One of the challenges of double wall HDPE drainage pipe is that it is exceptionally light. This can make uplift management during grouting particularly challenging.

The Solution

In order to manage buoyancy during the annular grouting, the boring contractor installed longitudinal blocking on each of the carrier pipes during installation. To reduce the uplift by six times compared to flowable fill, CJGeo proposed a 30lb/cuft cellular grout for the annular grouting.

Between the blocking and the very low density CJFill-Ultra Lightweight cellular grout, single lift grouting was possible without damaging the new carrier pipes. Single lift grouting eliminates the risk of trapped air pockets or partial fills associated with multi-lift grouting.

Due to the relatively low volume, and to reduce heat of hydration, wet batch generation using slurry from a local ready mix plant was used.

Speak With An Expert

Facing a similar challenge to this railroad bore annular space grouting project? Give us a shout or shoot us a text. Click the state marker for the location of your project for contact info for the appropriate rep.

Tunnel Adit Fill

The Job

This tunnel adit fill project is part of the Purple Line project outside of Washington, DC. Specifically, the adit is located at the pedestrian connection between the Purple Line project and WMATA’s Bethesda station on the Red Line.

The Challenge

Plans call to connect the Purple Line to the Red Line using an adit constructed during the original construction of the Red Line. The adit is approximately 30 feet wide by a 35 foot tall arch. During preparation to blast from a shaft dropped adjacent to the station, a fault was identified passing through the adit.

The construction and design teams were concerned about stability of the adit during blasting operations as the Purple Line access tunnel was excavated towards it. The team determined that filling the adit to plug and stabilize it during blasting would be the most risk appropriate move.

Filling the adit would fulfill the design challenge of stabilizing the rock during blasting. However, it created the following challenges:

  • the tunnel adit fill material would need to be removed after blasting was completed
  • the adit is approximately 100 feet below grade
  • there is very limited space up top
  • material couldn’t segregate, and had to be pumped approximately 250 feet in addition to the 100 foot drop

The Solution

The tunnel engineer of record recommended CJGeo to the contractor. The EOR is familiar with CJGeo’s cellular concrete generation and placement expertise, and thought that cellular concrete would be the lowest risk way to fill the adit, while facilitating excavation and removal afterwards.

CJGeo took five days onsite to fill the adit, in lifts up to eight vertical feet. Due to the potential dead load from the rock cover, 400psi CJFill-Standard was the material of choice. By using our colloidal mixing dry batch process, the material set off quickly, ensuring that it would not consolidate during cure as lower energy mixing methods can suffer from.

Speak With An Expert

Facing a similar challenge to this tunnel adit fill project? Give us a shout or shoot us a text. Click the state marker for the location of your project for contact info for the appropriate rep.

New Jersey permeation grouting

The Job

This New Jersey permeation grouting project is located in Elizabeth, New Jersey. It is at a large wastewater treatment plant owned by the JMEUC.

The Challenge

During installation of a new building on site, a large excavation was required. Primarily comprised of H piles and wood lagging, it crossed a 24 foot wide influent conduit. The influent conduit is a double barrel box structure, cast in place on 12 inch thick bed of open graded stone.

During test pitting to the bottom of footing elevation, the test pit appeared to be tidally influenced. The site is immediately adjacent to a creek that feeds into the Elizabeth River. At high tide, and due to the permeability of the stone layer, inflow into the test pit was not controllable, and was higher than the footing elevation.

Specific challenges here included:

  • potentially high velocity water flows due to tidal influence
  • 12 foot minimum spacing of grout holes due to structure wall locations
  • potential fouling of bedding stone with fines

The Solution

The general contractor reached out to CJGeo about grouting the stone bed. The structure is 24 feet wide, but only has a single, eight inch wall down the middle.

CJGeo proposed that a coring contractor drill a two inch core down through the center and side walls from the surface. This gave us three access points to place grout from at each location.

Due to the large grout hole spacing, CJGeo selected acrylic grout. Acrylics are excellent for this type of application because they are exceptionally low viscosity (pump & flow pretty much like water).

A single CJGeo chemical grouting crew performed the acrylic grouting over two days onsite. Afterwards, infiltration into the excavation was down to a submersible garden hose pump. The use of acrylic grout ensured that:

  • coverage was uniform despite the large distance between placement points
  • any fines fouling the bedding stone were uniformly bound together, immobilized & made impermeable

Speak With An Expert

Facing a similar challenge to this New Jersey permeation grouting project? Give us a shout or shoot us a text. Click the state marker for the location of your project for contact info for the appropriate rep.

Outfall Leak Grouting

The Job

This outfall leak grouting project is located near Emporia, Virginia. The work is located at two different stormwater ponds at an industrial scale solar facility. The facility is owned by Dominion Energy.

The Challenge

This facility has a mix of both dry and wet ponds. At two wet ponds, leaks developed along the outfall pipes, which prevented them from holding water long term. During a precipitation event, water would build up, but then afterwards, slowly drain out by piping alongside the outfall pipes. In order to turn over the facility to the owner, the contractor needed to address the leaks to ensure the ponds functioned as designed.

The Solution

Due to the small diameter of the pipes, they weren’t accessible from the inside. CJGeo proposed grouting along the pipe alignments using single component expanding chemical grout. The pipes are reinforced concrete.

To facilitate this, CJGeo drove sacrificial injection tubes along both sides of each of the two pipes. No grout returned to the inside of the pipes, which confirms that the root cause of the problem was poor control of the backfill, as opposed to problems with the pipe joints. When bedding isn’t properly installed, and backfill properly compacted, water can flow outside of stormwater pipes, which is what was happening here.

Speak With An Expert

Facing a similar challenge to this outfall leak grouting project? Give us a shout or shoot us a text. Click the state marker for the location of your project for contact info for the appropriate rep.

SOE Leak Grouting

The Job

This SOE leak grouting project is located in Alexandria, Virginia. It is part of the RiverRenew project, which is a large CSO tunnel and drop shaft project. This location is immediately adjacent to the Woodrow Wilson Bridge, and the Potomac River.

The Challenge

At a drop shaft location, the contract installed two parallel slurry walls between an existing combined sewer box culvert and a drop shaft to the new tunnel. During excavation of the pit, two high volume leaks, each around 125GPM opened up below the existing conduit.

The customer installed road plates to stabilize the area, and pumped flowable fill behind the road plates. This provided short term stability to the area, but did not address the high velocity flow of water through an unanticipated open graded sand seam that was causing the leaks.

The Solution

CJGeo mobilized a grouting crew capable of performing both high volume geotechnical polyurethane grouting and acrylic permeation grouting at the same time for this SOE leak grouting work. The first step was to install CJGrout 35NHV61 to fill voids which had washed out immediately behind the road plates.

After grouting the bulk voids and slowing the velocity of the leaks, CJGeo installed acrylic grout up to 20 feet behind the slurry wall face. The only way to reliably stop water flow through sands is to bind them together with a very low viscosity grout. The acrylic grout installed on this project has a viscosity less than 10 centipoise. This allows it to uniformly permeate the sands, react into a cooked egg white consistency, and make the treated sands impermeable.

Speak With An Expert

Facing a similar challenge to this SOE leak grouting project? Give us a shout or shoot us a text. Click the state marker for the location of your project for contact info for the appropriate rep.

HDPE Annular Grouting

The Job

This HDPE annular grouting project is located in Portsmouth, Virginia. The project owner is the Hampton Roads Sanitation District, which provides sanitary transmission and treatment for coastal Virginia.

The Challenge

CJGeo was originally part of this project to perform abandonment grouting of around 1000 linear feet of 24″ gravity sewer. During construction, a 1600 linear feet of 36″ gravity sewer in the project area was inspected. The inspection revealed multiple defects needing repair. The design and construction team identified slip lining as the most appropriate repair.

Slip lining generally requires annular grouting between the new carrier pipe and the original pipe. In this case, fused 24″ solid wall HDPE was the slip lining material of choice. This left an approximately 6″ annulus to be fill in order to ensure long term stability of the new pipe and the surrounding ground.

The Solution

CJGeo proposed using 30lb/cuft CJFill-Ultra Lightweight cellular concrete for the annular grout. Cellular grout is the ideal material for HDPE annular grouting because the placement pressures are incredibly low. This is because cellular grout is primarily air, because of its high preformed foam content.

Speak With An Expert

Facing a similar challenge to this HDPE annular grouting project in Virginia? Give us a shout or shoot us a text. Click the state marker for the location of your project for contact info for the appropriate rep.

Apartment Floor Lifting

The Job

This apartment floor lifting project is on a military facility in Washington, DC. During turnover of a unit, the property management company discovered signs of significant settlement affecting the interior floor. There was a significant crack showing through vinyl flooring, and up to 1.5 inch gaps below the baseboard in a carpeted room.

The Challenge

The primary challenge for the general contractor on this project was repairing the floor as quickly as possible. The unit was only going to be unoccupied for about two weeks between tenants. The contractor not only had to repaint, install all new floors, but also had to address this settlement.

The Solution

The general contractor reached out to CJGeo to assess the feasibility of raising the floor using polyurethane grouting. Having worked together in the past, the general contractor knew that CJGeo’s polyurethane grouting process is significantly faster than traditional mud jacking or concrete replacement.

A single CJGeo polyurethane grouting crew took less than a day to complete this apartment floor lifting repair. The total area grouted was around 750 square feet. Using CJGrout 28FDL, the grouting process corrected all of the settlement. Because polyurethane grouts are about 95% lighter than traditional grout and backfill materials, the likelihood of the grout material inducing future settlement is virtually eliminated.

Speak With An Expert

Facing a similar challenge to this apartment floor lifting project? Give us a shout or shoot us a text. Click the state marker for the location of your project for contact info for the appropriate rep.

48 Inch RCP Joint Repair

The Job

This 48 inch RCP joint repair project is located in Raleigh, North Carolina. The pipe is located at a commercial facility. The slope covering the pipe experienced a slope failure. Upon inspection, six joints were showing signs of soil infiltration and water exfiltration.

The Challenge

The primary challenge for the general contractor on this project was minimizing cost and time. It would have been expensive and disruptive to excavate the pipe. Cover depths were up to 15 feet, and there was a road that would be impacted by excavation, as well.

The exfiltration from the leaking joints was washing away bedding material and adjacent backfill. This caused significant amounts of erosion, and destabilized the slope soils by completely saturating them.

Piping outside of reinforced concrete pipe is an ideal candidate for polyurethane grouting.

The Solution

CJGeo worked with the general contractor and owner’s civil engineering to design a grouting program to repair the pipe. The general concept for this 48 inch RCP joint repair project was to backgrout the pipe with rigid geotechnical polyurethane grout. CJGrout 35NHV61 was the grout of choice; it can be injected directly into flowing water, provides nearly 10ksf in compressive strength, and migrates into both large and small voids with ease.

A CJGeo polyurethane grouting crew took a single day to perform the repair. The average circumferential void around the pipe was nearly nine inches. Cutoff criteria were:

  • grout hole to joint communication
  • cross hole communication

Speak With An Expert

Facing a similar challenge to this 48 inch RCP joint repair project? Give us a shout or shoot us a text. Click the state marker for the location of your project for contact info for the appropriate rep.

Top