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Granby Foundation Lift & Stabilization

PROBLEM

Located in the mountains of Colorado, this 15 year old residence had settlement occur in the foundation, and resulting damage to exterior facings, windows, doors and casings as well as interior damage to drywall and wall finishes. 

The owner had recently purchased the home and was referred to CST by a previous customer. CST was contacted to assess the issues with the foundation, and provide a solution to repair the settled foundation and mitigate against future settlement. The homeowner wanted the repairs made on the foundation prior to beginning additional mechanical and cos-metic repairs such as replacing cracked windows, doors, and interior/exterior finishings which needed to be completed soon as cracks and gaps were causing issues with keeping the cold winter air out of the home. 

SOLUTION

An initial site elevation survey conducted by CST revealed that the home’s foundation had experienced settlement of approximately 2 inches. 

The biggest area of differential movement had occurred in the great room and front entrance areas of the home. 

CST performed Soil Density tests in order to determine the weak soil zones and set benchmarks prior to designing the injec-tion plan. Once injection locations were determined, CST installed a high density expanding structural polymer into the soil, at determined depths. Working from the exterior, with crew members monitoring from the interior great room, the team lifted the settled areas back to original elevation. 

RESULT

The entire repair of this home’s foundation was completed in less than 2 days. CST lifted the settled foundation without causing additional damage to the home and adjusted windows enough that they were able to be latched where previously they had not. 

CST’s repair process is non-invasive and the residents were able to stay in their home during the repair. 

By stabilizing the foundation’s underlying soils, the home was protected against any future settlement or movement, allowing the owner to quickly move forward with completing the mechanical and cosmetic repairs to their home. 

CHALLENGES

  • Completing foundation repair in mid-December in order to protect the interior of the home and it’s occupants from winter elements. 
  • Lift the foundation without causing additional damage to the home’s finishes. 

BENEFITS

  • In Situ, no excavation foundation repair. 
  • Repairs are completed quickly, with very little disruption or mess. 
  • Families may stay in their homes during repair. 
  • Effective and efficient, long lasting protection for your assets. 
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Concrete Slab Lift Asphalt Pavement Lift Soil Stabilization – Pueblo, CO

This highway roundabout located in Pueblo West, Colorado had experienced settling of between 2 to 3 inches in areas of the concrete panels. The settlement had occurred as a result of poorly compacted soils. The settlement of the slabs had created a negative drainage situation, causing water to pool against the curb and gutter instead of draining away from the structure as originally designed.

As part of a larger paving project, Martin Marietta, a heavy highway contractor working on the section of roadway that included this roundabout, needed a solution to lift the settled concrete panels and correct the drainage issues the settlement had caused without ob-structing traffic flow through the rounda-bout and connecting roadways.

CST partnered with Martin Marietta to create a repair plan that would allow traffic to continue to flow through the roundabout while the panels and adjoining asphalt were lifted back to original profile. CST’s technologies were used to repair the settled slabs and pavement. The process employs injecting an expanding structural polymer that densifies and compacts soil, fills voids, and lifts settled concrete and asphalt. A rubberized barrier was used to assist injection crews in staging and protecting injection hoses across the roadway which allowed traffic to safely continue through the roundabout during the repair process. Martin Marietta used a water truck to wet down the roadway and panels to assist CST’s injection crew in locating and correcting the areas of settlement prior to beginning injections.

The settlement and soil compaction issues were efficiently and effectively addressed and corrected while allowing traffic to continue use of the roundabout and roadways during the repair. The con-crete panels and adjacent asphalt pavement were lifted back to original design profile which corrected the drainage problem.

The repair was completed in less than a day, preserving the existing concrete, correcting drainage, and guarding against future damage erosion, settlement, or damage to this roundabout structure and adjacent roadway.

CHALLENGES
Maintaining traffic flow during repair.
Safely staging injection equipment in the roundabout area.
Restore drainage away from the concrete panels.

BENEFITS In situ, no excavation repairs
Little to no downtime
Fast, cost -effective, permanent
Preserves and extends the life of existing structures & pavement

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Colorado Bridge Approach Slab Settlement Lift

Bridge Approach Slab Settlement Repair – Crystal Valley Parkway, CO

Asphalt Pavement Lift of a Bridge Departure where the Subgrade had settled and the pavement needed to be lifted

In Castle Rock, CO, along the Crystal Valley Parkway, the Town of Castle Rock, CO was experiencing bridge approach slab settlement of 1,900 SF of bridge approach, departure, and sleeper slabs on two bridge ends and adjoining pavement. Settlement of adjacent sidewalk had also occurred causing an unsafe driving situation as well as dangerous conditions to pedestrians utilizing the crossover sidewalk area. The unstable subgrade reaching below the sleeper slab would need to be treated to stabilize the area before mill and fill of asphalt pavement could be performed.

Bridge Approach Slab Settlement Solution

CST partnered with the Town of Castle Rock, utilizing their Deep Injection process to treat unstable soil, lift the slabs, and realign sidewalk and pavement areas. Dynamic Cone Penetrometer soil tests were performed to correctly identify the weak soil zones. Injection tubes were placed at depth and expanding structural polymer injected to densify and provide stabilization of subgrade soils. Once the soil is stabilized, injections are continued to provide lift and realignment of the slabs and overlying pavement. The CST Deep Injection process provides proper support to the soil and heavy sleeper slabs to mitigate against future bridge approach slab settlement and movement, while also providing a solid subgrade for pavement.

Repairs were made in two shifts while allowing traffic to continue utilizing the area vs. time and money spent to reroute. Foundation soils were significantly strengthened to mitigate against future settlement. Bridge approach and departure slabs were lifted back to original elevation as well as stabilization and lift of sidewalk areas. Subgrade soils were quickly and effectively stabilized to provide a strong base for asphalt pavement mill and fill operations. The added benefit of water cutoff effectively arrests soil erosion within the area. Significant savings to municipalities and tax payers vs. alternative methods of rip out and replace. Extended use life of the bridge, sidewalk, and pavement.

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Douglas County Sheriff MSE Wall Repair – Highlands Ranch, CO

Douglas County Sheriff MSE Wall Repair – Highlands Ranch, CO

Concrete Stabilization Technologies, Inc. partnered with the Douglas County Facilities Management division of Douglas County, CO to stabilize the MSE walls at the Douglas County Sheriff Sub-Station in Highlands Ranch, CO.

CST was referred by a geotechnical engineering firm to provide a solution to stabilize portions of distressed MSE wall. The geotechnical report indicates low density soils between base of wall and top of storm sewer pipe installed approximately 16’ prior to MSE wall. A section of the MSE wall was slated to be rebuilt after soil stabilization project was completed.

Patented processes were used to increase bearing capacity and stabilize the West and East MSE wall in the sewer trench area of the facility for an area of approximately 60 LF. CST’s deep injection method was performed to reinforce low density soils between top of storm sewer pipe and bottom of MSE wall. The distressed MSE wall was monitored with laser levels during the injection of expanding structural polymer into the underlying soils. Injections were also performed around a manhole to void fill and seal joints.

Video camera inspections were done before and after injection to verify pipe condition. The patented injection processes used in this stabilization project saved the customer from excavating and possibly replacing the pipe.

This project was completed on time and on budget!

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CDOT HWY 52 CMP Rehabilitation – Hudson, CO

The Problem

The deterioration of Corrugated Metal Pipe, (CMP) at the flow line is a result of exposure to oxygen and moisture mixed with metal, which causes rust. Other factors such as soil conditions and the acidity of the water flow will also affect the rate of deterioration.

When CMP deteriorates, water runs under the pipe instead of through and undermining of the structure occurs. Sink holes above the structure will begin as the soil collapses. The underlying bedding material or support fill is then exposed to water flow, and begins to erode away, causing voids and loss of structural support. This creates a potentially dangerous situation with the possibility for failure of the entire structure and collapse of the overlying roadway.

Concrete Stabilization Technologies, Inc.’s Field Consultant, Richard Hess was contacted by Colorado Department of Transportation Maintenance Department representative for Region 4, Zach Junk, concerning a deteriorated culvert beneath Colorado State highway 52 near Hudson, Colorado. The traditional method of tearing out and replacing eroded culvert pipe had proven to be a time consuming and disruptive process which had lead CDOT to seek a less disruptive solution.

The Solution

CST met on site with Mr. Junk and after reviewing the area, determined that our CMP repair process was an ideal fix for this particular culvert and overlying roadway. Subgrade stabilization injections from the roadway surface were included in the repair plan where exfiltration of soils through the rusted out pipe had caused variable settlement in the road surface above the culvert, requiring steel plates as a temporary fix against further damage to the road surface and vehicles. Thus, part of the CST complete solution was to not only secure the metal sheets to the old CMP but to also inject from the road surface above to 3′ to 4′ to reinforce the subgrade while replacing soil lost to exfiltration.

CDOT maintenance representative Zach Junk stated that he, “liked the fact that they didn’t have to close the road or detour traffic like they normally do when having to replace pipe.”

Structural integrity of the existing pipe was a concern and it was discussed that not only would the structural integrity of the pipe be restored, but also restoration of correct flow into the repaired pipe.

The ditch company expressed concern of subsequent debris buildup such as weeds and silt that may disturb the water flow. The repair design and installation is such that this concern is positively addressed and re-establishes water flow with no added obstruction.

After an in depth investigation and review of the site, it was assured that this would be an ideal repair process for the deteriorated culvert and CST was given the approval to begin the project.

Crews arrived on the job site around 10:00 a.m. to begin repairs. A significant amount of water was running in the ditch containing the culvert. While water was shut down, crews began deep injection to stabilize the sub-grade on the overlying roadway. Injections were made from the surface at a depth of approximately 3 ½ feet on 5 foot centers, while monitoring at the surface for move-ment. After the subgrade stabilization was complete, it was determined that one of the two overlying road lanes was in good shape and the other lane would only require select asphalt patching once repairs were complete.

The Results

Neither lane required any excavation during repair, due to CST’s unique in situ polymer injection process. Once stabilization of the roadway was complete, the crew began repairing the corrugated metal pipe. Repairs and cleanup were completed in one working shift. The Frico Ditch Company representative confirmed that “the ditch is flowing well”.

Benefits of CMP Repair

The patented CMP repair process is quick and non-disruptive. The pipe is first cleaned of any sticks, rocks, and other debris. Repairs begin on the outlet-side of the pipe where the new sheets of specially coated metal are laid, ensuring the corroded water line is covered. The metal sheets are then attached to the ribs of the pipe with corrosion resistant fasteners. Overlapping sheets are then continuously added and secured in place until the length of the pipe is completely reinforced. In this case, the culvert being repaired was approximately 50 feet long and 5 feet in diameter with the corrosion/water line reaching approximately one third of the way up the side wall of the culvert. Once the new metal sheets are all placed, and secured, expanding structural polymer is injected beneath the metal sheets, to fill any voids beneath the pipe. Excess material is removed and a tar coating is applied to the top edge of the new metal sheeting as an extra protective measure to deter rusting and to ensure longevity.  The benefits include:

  • No-excavation
  • Less disruptive
  • Reduces costs
  • No road or rail closure or downtime
  • Repair equipment & material are easily mobilized
  • Extends lifetime of invert
  • No loss of flow
  • Environmentally inert materials
  • Completely restores structural integrity

 

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Middle School Chiller Lift – Denver, CO

A Denver, Colorado, middle school experienced the effects of expansive soil on a pair of large, 16 ton ice chiller thermal storage units used for numerous school refrigeration needs. Each storage unit was placed on independent, 32,000 lb. reinforced concrete pads to maintain a continuous, even elevation for support and proper unit function. Substantial damage and malfunction to each unit was highly probable if the supporting concrete pad was uneven.

Expansive soils shifted beneath the concrete support pads causing an unsatisfactory level for the chiller units to continue functioning. To avoid damage to the units, both were taken out of service until a repair plan was initiated. The concern for the school district was to have the chiller units functioning at capacity, supported on level concrete pads in time for the upcoming school year.

Due to the cost and downtime for the school and potential hazard of damaging each unit through relocation, a choice was made to use a high-density, polyurethane grouting technique. CST’s Deep Injection Process densifies weak soil zones at specified depths to resupport each pad. This process solved three main concerns:

  1. Eliminate relocation of the units
  2. Stabilized volatile soils
  3. Level the units to 3/4” tolerance to restore functionality and capability.

After elevation profiles were taken, injection locations were determined to stabilize weak soil strata and realign the chiller units. Operators injected at depths of 3 feet at an angle to allow greater material coverage for maximum unit stability.

After stabilizing the weakest soil zones, additional injections realigned the pads within the 3/4” tolerance for the ice chillers to function properly without damaging each unit.