Basement Wall Load Reducing Fill
The Job
This basement wall load reducing fill project is located in Lexington, Virginia, on a campus of Washington & Lee University. The scope is part of a new academic building construction project. The building will house the Williams School of Commerce, Economics & Politics.
The Challenge
The building is on a sloping site. The front of the building will be slab on grade, and the back half of the building will be a walk-out basement level. The transition between the two floors is an approximately fifteen foot tall wall with two 90’s.
The basement wall is designed to be braced by the floors and building. However, the floors & building couldn’t be built until the wall backfill was in place. In order to backfill the wall, it would need load reducing fill, or it would need temporary bracing.
The Solution
A structural engineer recommended the general contractor reach out to CJGeo about backfilling the wall with CJFill-Ultra Lightweight low density fill. Working with the structural EOR, geotech EOR & general contractor, CJGeo developed a backfilling plan that would allow backfilling the wall over three days while eliminating the need for temporary bracing.
CJGeo poured three lifts, each about 4.5′ deep. A dry batch process plant running at up to 200 cubic yards per hour and using preformed foam from Aerix Industries backfilled the wall in three days.
Speak With An Expert
Facing a similar challenge to this basement wall load reducing 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.
Low Density Bridge Underfill
The Job
This low density bridge underfill project is located on Interstate 95, in Philadelphia, Pennsylvania. The scope is part of a large widening and reconstruction project. The bridge is located over Carver Street, just south of the Tacony-Palmyra Bridge.
The Challenge
As much underfill as possible had to be in place prior to the bridge demolition. Otherwise, it would have been impossible to demolish the deck, beams & other structures during a limited closure. There are also multiple underlying utilities which would not tolerate the nearly 5ksf of additional dead load from using traditional flowable fill.
The Solution
In order to fill up to the bottom of the beams, CJGeo designed a mass fill placement plan that stepped in at a roughly 1.5H:1V slope. CJGeo batched CJFill-Ultra Lightweight with a 40psi at 28 day minimum compressive strength using the dry batch process onsite, and placed at times more than 1,000 cubic yards per day.
Once the CJFill-UL was in place to complete this low density bridge underfill, the customer was able to demolish the bridge and beams, only need to bring in a few feet of crushed stone for the pavement base, and then pave the roadway to restore traffic. This was performed during an accelerated closure to minimized traffic disruption. The work took around two weeks, using the dry batch generation method.
Speak With An Expert
Facing a similar challenge to this low density bridge underfill 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.
Lightweight MSE Wall Backfill
The Job
This MSE wall lightweight backfill project is located near Chester, Virginia. The MSE wall is part of a ramp reconfiguration and lengthening project at the interchange of Rt 10 and Interstate 95. Specifically, this ramp is from westbound Rt 10 to northbound Interstate 95.
As part of the ramp lengthening and realignment, the ramp needed to shift out onto an existing embankment.
The Challenge
There was insufficient right of way to widen the embankment without acquiring additional right of way. In order to shift the road without acquiring additional land, the geotechnical engineer of record, Schnabel Engineering, recommended to building a mid-slope MSE wall. The wall design includes a lightweight reinforced and retained zone to eliminate any net change in load. Effectively, when the slope is notched for the MSE wall construction, the difference in fill density allows for increased height.
The Solution
The existing soils were rough 125lb/cuft, and the CJFill-Ultra Lightweight backfill is 30lb/cuft. This allows for two additional feet of fill depth for every foot of undercutting. The final MSE wall lightweight backfill design included a 140psi minimum 28 day compressive strength (ASTM C495).
It took three lifts to backfill the wall, which was at most eight feet tall, and roughly 150 feet long. A composite drain on the slope addresses and water migration through the soil slope, and ties into a gravel bed at the base of the CJFill-UL load reducing fill.
Speak With An Expert
Facing a similar challenge to this MSE wall lightweight backfill 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.
Box Culvert Void Filling
The Job
This box culvert void filling project is located near Fredericksburg, Virginia. The Virginia Department of Transportation owns and maintains the structure, which conveys a stream under a rural divided highway. As part of a rehabilitation project, extensive cracking in the structure (a double barrel six foot by six foot box), was being patched with repair mortar, and some cracks epoxied.
The Challenge
At the start of project, the general contractor discovered extensive voids outside of the structure. These voids were allowing significant amounts of the stream flow outside of the box culvert (piping). This was cause for concert regarding the specified repair mortar application and epoxy injection.
The general contractor reached out to CJGeo about filling the voids with grout prior to the patching and repair operation.
The Solution
CJGeo proposed grouting all the voids outside of the box culvert with CJGrout 35NHV61. 35NHV61 is a hydro-insensitive, structural polyurethane grout. Its NSF61 potable water certification makes it excellent for work on drainage structures.
The owner, Virginia’s Department of Transportation, required water testing before, during and after grouting. This water testing specifically looks for MDI. All of the water testing, which was performed by a third party environmental laboratory, found zero MDI in any of the water samples.
It took three days onsite to complete the grouting. Some hairline cracks that were still damp after the bulk box culvert void filling work. CJGeo grouted these cracks with a hydrophilic chemical grout to make them completely dry.
Speak With An Expert
Facing a similar challenge to this box culvert void filling 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.
Massachusetts Lightweight Fill
The Job
This Massachusetts lightweight fill project is located at Boston’s Logan International Airport. It is part of Logan Forward continuing improvements to the airport.
The Challenge
As part of this project, the general contractor installed two cast-in-place barrier walls. The space between the barrier walls is between four and nine feet. The walls are curving, have non-vertical faces, and bear on a curving, non-horizontal existing podium slab. The gap between the walls needed to be filled in order to pour a housekeeping slab spanning between the walls.
This work is all on an existing podium structure. So, the fill density between the two walls had to be as low as possible.
The Solution
CJGeo proposed filling between the two walls with CJGrout 20SDB. 20SDB has a similar density and compressive strength to typical expanded polystyrene (EPS, or Geofoam) blocks. However, unlike geofoam blocks, 20SDB:
- is pumped, so doesn’t require trimming, and fits to any shape
- expanded onsite, so logistics are significantly simpler
- cures within a few minutes, so is still quick
- not affected by petroleum products
A CJGeo polyurethane grouting crew took a single shift onsite to install the 64 cubic yards of CJGrout 20SDB. The general contractor began installing the topping slab the next day.
Speak With An Expert
Facing a similar challenge to this Massachusetts lightweight fill project? Give us a call or send us an email by clicking on the state marker to locate the Preconstruction Manager that services your area.
Sheet Pile Joint Sealing
The Job
This sheet pile joint sealing work is part of the Thimble Shoals parallel tunnel project. The project is located between Islands 1 and 2 of the Chesapeake Bay Bridge Tunnel. The Chesapeake Bay Bridge Tunnel crosses the opening of the Chesapeake Bay, connecting Norfolk/Virginia Beach and the Eastern Shore.
The Challenge
Water was leaking out of a joint in the precast splash wall adjacent to the TBM slurry separation pit. Any time it rained, precipitation landing in the slurry pit would flow out of gaps in the sheet pile wall. It then passed through the roughly 3′ of soil between the sheet pile wall and splash wall, and then out through joints in the splash wall.
The Solution
CJGeo proposed using a single component, hydrophilic chemical grout to seal the joints. Hydrophilic grout is best for this particularly repair because:
- the area is rather dynamic, so hydrophilic’s ability to flex and stretch without tearing helped to ensure longevity
- the area is constantly exposed to moisture, so dimensional stability is not a concern.
A CJGeo chemical grouting crew of three people completed the sheet pile joint sealing repairs in less than a day. Some chemical grout extruded out through the joint in the splash wall. It was broken off flush with the surface and disposed of offsite.
Speak With An Expert
Facing a similar challenge? 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.
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. After grouting, it’s important to tamp the approaches. Because the rails are clipped, lifting the panels lifts the rails & ties in the approaches. If the approaches aren’t tamped, the crossing can teeter totter, which is bad. Tamping is done immediately after grouting, and preferably before any rail traffic resumption.
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.
Speak With An Expert
Facing a similar challenge? 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 York Tub Crossing Lifting
The Job
Eight panels of StarTrack modular grade crossing tubs settled. As a result of the settlement multiple clips broke. This tub crossing lifting project was for a short line serving an industrial facility in Geneva, New York.
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 tub crossing lifting work without impacting rail traffic, and the facility was able to function normally throughout the repair, which took less than a day.
Polyurethane grouting with CJGrout is an excellent alternative to cement based grouting, because:
- CJGrout cures within a few minutes, so there are no limitations on rail traffic
- CJGrout is not brittle, so does not break down in dynamic environments like thin layers of cement-based grout tend to do
- CJGrout application is not weather dependent; in this case, it was snowing during installation
- CJGeo controls the entire CJGrout logistics process, so there’s no need to wait on ready mix trucks or coordinate deliveries of material that goes bad within a few hours of offsite mixing
Speak With An Expert
Facing a similar challenge? 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.
Illinois Spillway Grouting
The Job
A spillway serving as a dam for a lake owned & maintained by a property owner association outside of Carbondale, Illinois stopped having water flowing over the spillway, requiring spillway grouting. The property owners determined that the lake was draining through voids under the spillway slab. This made them concerned about destabilization of the spillway, which was the sole access for six homes.
The Challenge
The flow velocity was rather high, and immediately on the other side of the spillway was a 30′ cliff. The water was designed to spill over as a waterfall. Given the extraordinary difficulty of retrieving any material washed over the waterfall, the grout had to have an exceptionally fast set. It also needed to provide adequate bearing capacity for the roadway slabs.
The Solution
CJGeo proposed grouting below the spillway with CJGrout 40NHL. CJGrout 40NHL is usually used for differential settlement correction. CJGrout 40NHL performs well for differential settlement correction because it reacts very quickly. It’s used for medium duty lifting, such as highway pavement, so it would provide more than enough bearing capacity.
The owners were very excited that it would be significantly less expensive to grout the existing spillway than to have someone local install a portadam and replace the entire structure. CJGeo mobilized a single polyurethane grouting crew to the site. They stopped the leaks and kicked all the water flow over the spillway in a single day.
Speak With An Expert
Facing a similar challenge? 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.
I-64 Soundwall Backfill
The Job
VDOT’s I-64 widening project is a multi-phase widening of Interstate 64 between Richmond & Newport News. This soundwall backfill work occurred as part of Segment 2, near the Queen’s Creek bridge.
The Challenge
Approximately 150LF of a combination sound & retaining wall needed to retain more than 10′ of backfill. In order to keep the drilled foundation size consistent along the alignment, the backfill material needed to be significantly lighter than the soil backfill used in other segments, where there was minimal retained depth.
The material needed to be freely-draining and less than 40lb/cuft. To ensure proper drainage, the lightweight fill material couldn’t impact the function of the combination drain waterproofing system applied to the wall.
The Solution
CJGeo proposed backfilling the affected wall segments with 30lb/cuft CJFill-UL. Used extensively by VDOT for backfilling the retained zones of MSE walls, CJFill-UL provides significantly better bearing capacity than soils or aggregates, and once cured does not apply lateral loads to the structures it is placed against.
During installation, lateral pressure from the cellular concrete is simply the hydraulic head. Hydraulic head is calculated by multiplying the pour thickness, in this case 5′, by the wet cast density, here 30lb/cuft, so 150PSF. Because CJFill-Ultra Lightweight cellular concrete does not contain any aggregate, there is no internal friction to contribute towards lowering pressures.
CJGeo placed approximately 200CY of CJFill-UL for the soundwall backfill the wall in two pours, each approximately 5′ thick. The contractor was able to place the pavement base on top of the material the following day.
Speak With An Expert
Facing a similar challenge? 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.
