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Commercial & Industrial

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

Lightweight Tank Foundation

The Job

This lightweight tank foundation installation project is located in Baltimore, Maryland. During an industrial facility expansion, a new blending tank was being installed at the top of a retaining wall. In addition concerns about lateral loading on the wall, the area is generally known to be built with uncontrolled fill over compressible soils, so settlement is a concern.

The Challenge

Due to the presence of industrial waste and debris in the area, light duty deep foundations such as helical piles are generally difficult to install. To avoid inducing settlement, the geotechnical EOR reached out to CJGeo for lightweight fill options to net out the increased weight of the mat foundation and blending tank.

Based on loads, CJGeo suggested a 25lb/cuft cellular grout with a compressive strength of at least 50psi. At this density, the engineer was able to balance all loads with a 4′ deep undercut. The undercut extended a few feet out around the perimeter of the tank foundation.

The Solution

First, the concrete foundation contractor excavated the pit. Then, CJGeo mobilized to the site and placed 110CY of 25lb/cuft CJFill-Ultra Lightweight cellular concrete into the pit. The lightweight tank foundation placement took less than an hour. The foundation contractor was able to start setting steel and forms the following morning.

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Facing a similar challenge to the one we solved with this lightweight tank foundation? 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.

Hotel Basement Water Intrusion Grouting

The Job

This basement water intrusion grouting project was at a hotel in Baltimore, Maryland. It had a continuously wet floor in the basement utility room. Water was oozing out from under the power feed bank housekeeping slab. The housekeeping slab sits directly on top of the floor slab. There were two presumed point sources:

  • the unsealed joint between the floor and the wall,
  • and the power feed conduit wall penetrations.

The pit where the power conduits came through the wall and turned up into the power feed cabinets was 18″ deep, and always full of water.

The Challenge

Extensive exterior drainage work did not work. It presumed that surface water was flowing down the outside face of the basement wall. Then, through the unsealed floor:wall joint and/or into unsealed joints in the conduits and then through the conduit penetrations. The exterior drainage improvements re-waterproofed approximately 500sqft of wall. They slowed, but did not completely stop the water intrusion.

A forensic engineer overseeing the project reached out to CJGeo about performing chemical grouting inside of the utility room to underseal the floor, and to seal the conduit penetrations.

The Solution

CJGeo proposed chemical grouting utilizing a low viscosity hydrophobic prepolymer chemical grout.

Fibrous material soaked in grout was placed into the utility conduit openings to seal them against water intrusion. The grout injected through the floor extruded up through the joint between the wall and floor, and also through various cracks in the floor.

Upon completion of the basement water intrusion grouting by CJGeo, the conduit pit was dry, and there are no longer any leaks.

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Facing a similar challenge to this basement water intrusion 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.

Dollar Store Floor Void Filling

The Job

This floor void filling project is located about three hours west of Richmond, Virginia. A commercial contractor was performing a full gut renovation of a dollar store in a strip center. The building was approximately 30 years ago, and there were no signs of floor slab failure or settlement.

The Challenge

While cutting through the floor to install utilities, a 3″ void was discovered below the floor. Exploratory coring determined that voids ranged from 0.5 to 4″ throughout approximately 11,000 square feet of the space. The front of the building is at grade, but the rear of the building has an approximately 7′ tall CMU stem wall, which was backfilled with common borrow during original construction.

The Solution

The general contractor reached out to the structural engineer to notify them of the problem. The structural engineer then reached out to the geotechnical engineering, who recommended polyurethane grouting as the best way to fill voids below a floor. The geotechnical engineering is familiar with polyurethane grouting from working with CJGeo on similar repairs in the past. They know that polyurethane grouting:

  • is very clean and fast, so is unlikely to slow progress
  • is very lightweight, so is least likely of all grouts to cause additional settlement
  • effectively cures instantly, allowing immediate resumption of activities in the area

CJGeo mobilized two geotechnical polyurethane grouting crews to the site and filled the voids over a period of two days. It took about 7,000 pounds of CJGrout 20SDB through approximately 500, 5/8″ holes to completely fill the voids. Cut-off criteria was cross-hole communication. The work was performed without disruption to the renovation activities.

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Facing a similar challenge to this floor void filling project by CJGeo? 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.

25MGD Sinkhole Leak Grouting

The Job

An underground minerals mine started to lose up to 8VF per day of mine due to water infiltration. Investigation of an adjacent stream uncovered multiple sinkholes which had opened up where the stream crossed a fault. Two sinkholes were adjacent to bridge abutments of a public road, which served as the sole access for multiple homes and farms.

The Challenge

Mine personnel started to self-perform chemical grout in some of the sinkholes. Due to the slow rate of grout installation relative to the water flow, the self-performed grouting was unsuccessful.

Due to endangered fish habitats within the stream, cementitious grouts weren’t allowed, and any chemical grouts needed to be certified for potable water use.

The Solution

CJGeo mobilized two polyurethane grouting crews in the third week of the Covid-19 pandemic to the site. To facilitate safe access to the site, all grouting was performed from aerial platforms reaching out over the work area.

During the grouting process, multiple additional sinkholes opened up; CJGeo would seal one sinkhole, and an adjacent soil filled feature would blow out. Super sacs of aggregate were dropped in the sinkhole throats to fill the bulk of voids, and then polyurethane grouting was performed below the super sacs.

Using nearly 50,000 pounds of CJGrout 35NHV61, CJGeo was able to slow the leaks to the point where no additional sinkholes formed, and the mine’s pumps were able to dewater the facility.

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Facing a similar challenge to this 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.

Sloped Pit Lightweight Backfill

The Job

This sloped pit lightweight backfill project is located in Western Virginia, at James Madison University. This work is part of the conversion the basketball arena at JMU in Harrisonburg, Virginia into a practice and competition facility for other sports.

The Challenge

An area of sloped stadium seating needed to be removed, and the mezzanine level floor extended over the sloped soil, which stayed in place, and onto a new wall at the toe of the slope. To reduce the likelihood of inducing settlement by adding up to 10 feet of backfill over the existing soils, the architect originally designed the backfill material as Expanded Polystyrene (EPS blocks). However, given the uneven soil slope, this would have been very challenging to install.

The general contractor reached out to CJGeo to see if there was a more practical load reducing fill.

The Solution

Working with the general contractor, architect and geotechnical EOR, CJGeo designed a backfill system that could be installed in fewer than six hours onsite, still provided a significant reduction in load, and cost significantly less than the foam blocks. The optimal product to meet the project criteria was 25lb/cuft CJFill-Ultra Lightweight low density flowable fill. CJFill-Ultra Lightweight has all the constructibility advantages of flowable fill, along with the following additional benefits:

  • is made at up to 200CY/hour onsite
  • provides up to 150CY of final material per load of raw material to the site
  • applies minimal lateral pressure on adjacent walls during installation
  • significantly reduces dead loads to underlying soils & structures

CJGeo generated the material onsite using dry batch generation, and placed the material in two lifts in order the limit the lateral loads on the new CMU wall during placement to 0.9psi.

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Facing a similar challenge to this sloped pit 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.

Stem Wall Backfilling With Cellular Concrete

The Job

This work was associated with the construction of a new academic building at a school in Lynchburg, Virginia.

The Challenge

Due to a sloped site, there was up to an 8′ difference in elevation between the existing ground and the desired finish floor elevation. Various options for filling the CMU stem walls included soil, aggregates and EPS foam blocks. EPS foam blocks were chosen to reduce loads on the footings, which would have required deep foundations in the case of soil or aggregate backfilling.

Due to the extensive sub-slab plumbing, the design called for EPS blocks cut to fit the curved walls & uneven ground profile, and then backfilled with 18″ of stone dust, to allow for the plumbers to dig and install the plumbing.

The Solution

CJGeo proposed installing 23lb/cuft cellular concrete to speed up the installation, reduce supply chain risks, and reduce the loads applied to the foundations and underlying soil.

CJGeo placed 1914CY of cellular concrete over three days onsite. All material was walkable within 12 hours, and the project saved approximately 3 weeks relative to the original design’s timeframe.

The cellular concrete was brought all the way to the bottom of the 6″ stone layer below the slab, and the plumbers were then able to excavate through the cellular concrete with a mini excavator and hand tools to install the plumbing, and the trenches were backfilled with 57 stone.

The total load using cellular concrete was reduced by approximately 120lbs/sqft relative to the EPS/stone dust backfill design.

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Facing a similar challenge to this 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.

Precast Lagging Wall Lateral Load Reduction

The Job

This load reduction backfill work as associated with the replacement of Scaife Hall, at Carnegie Mellon University, in Pittsburgh, Pennsylvania.

The Challenge

The H-pile and precast lagging wall is at the top of a steep slope. There is a Class I railroad line at the base. Because of site constraints, an HDPE stormwater detention structure is within the fill area. Along with extensive stormwater pipes and manholes.

In order to optimize the drilled shafts for the H-piles by reducing the lateral loads, the designer sought a lightweight, permeable backfill material that would not apply lateral loads once in place.

The Solution

CJGeo proposed 20lb/cuft CJFill-High Permeability cellular concrete. CJFill-HP would minimize lateral loading on the wall during construction, buoyancy of of the stormwater system components, and ensure a free draining material.

Because the material is permeable (modified ASTM D-2434 2.0cm/sec), it is freely draining and reduces hydrostatic loads on adjacent structures.

620 cubic yards of lightweight backfill were placed over two mobilizations to complete this load reduction backfill project.

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Facing a similar challenge to this retaining wall load reduction 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.

250000 Gallon Oil Tank Abandonment

The Job

This oil tank abandonment project is located in the nation’s capitol, Washington, DC. As part of decommissioning an underground oil tank at Howard University in Washington, DC, it needed to be filled with excavatable material that was lighter than the roughly 55lb/cuft heating oil it was designed to hold.

The tank is under a small empty lot. The lot is up for redevelopment in approximately three years.

The Challenge

For a complete decomissioning, the tank had to be completely full of grout. Since it sits within a planned basement excavation, the fill material has to be easily excavatable.

The Solution

CJGeo proposed 20lb/cuft cellular concrete for the oil tank abandonment grouting. This afforded plenty of factors of safety to reduce the likelihood of settlement induced by filling the tank and maximized excavatability. The removability modulus of 20lb/cuft (a quantifiable method for determining excavatability of various types of flowable fill) is much less than one. This means it is easily hand excavatable.

CJGeo placed the CJFill-Ultra Lightweight fill material over a period of two days onsite. Because cellular grout is highly mobile, no entry was required during the placement of the fill material, which designed a significant amount of risk out of the process.

The 1200CY placement was performed over two days onsite.

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Facing a similar challenge to this oil tank abandonment 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.

Fire Station Floor Lifting

The Job

This fire station floor lifting project is located about an hour east of Richmond, Virginia. The concrete slab on the grade floor inside of a fire station on the North Neck of Virginia settled up to two inches. As part of the investigation into the cause, an engineer discovered voids up to 8″ below the slab and multiple broken sanitary sewer pipes below the floor.

The affected areas needing slab foundation repair included a dayroom, kitchen & meeting hall.

The Challenge

In order to minimize disruption to the fire station’s operations, the proposed repair had to be quick, clean, and minimize uncertainty associated with the plumbing repair slab cuts.

The Solution

CJGeo performed ground improvement grouting of the underlying soils to 5′ below-grade utilizing plural component polyurethane compaction grouting, with CJGrout 35NHV. During the compaction grouting process (sometimes called structural polymer grouting), the CJGrout 35NHV lifted the floor back into place.

Because polyurethane grouts cure very quickly, the floor was repaired the day before the plumbing work was scheduled. This allowed the plumbers a stable work surface and eliminated the risk of stuck saws or sudden collapse of the floor during floor sawing for plumbing access.

Grouting sufficiency was verified by using pre & post-grouting DCP tests.

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Facing a similar challenge to this fire station floor lifting project by CJGeo? 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.

14′ CMP Repair

The Job

During a real estate transaction, civil engineers walked a 1400LF run of 14′ diameter multiple tunnels running underneath a strip center in Asheville, NC.

A previous inspection had indicated impending section loss of the pipe due to corrosion and had recommended grouting of incidental voids, but no work had been performed at that time.

The pipe, which had up to 20′ of cover, bypasses a large stream and runs under 200LF of building footprint, the main entrance roadway, two out-parcels, and ties into an NCDOT box culvert to discharge.

The Challenge

Significant debris was present in the pipe, and access was exceptionally difficult. Because dewatering was not practical, all work proposed had to be performed underflow.

The Solution

CJGeo proposed polyurethane backgrouting using plural component CJGrout material, specifically CJGrout 35NHV61.

CJGrout 35NHV61 is a hydro insensitive, moderate mobility grout designed for backgrouting in wet environments, and is certified for potable water contact.

Despite a bear wandering into the pipe during repairs, CJGeo crews successfully backgrouted the pipe to address piping and erosion outside of the structure over a period of two weeks. More than 40,000 pounds of CJGrout 35NHV61 were needed for this 14′ CMP repair project.

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Facing a similar challenge to this 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.

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