Drain Pan Void Fill Structural Support CDOT Region 1

A drain pan structure running adjacent to US-287 near Broomfield Colorado had experienced significant voids of varying severity beneath the structure. The drain pan was designed to move water away from the roadway during water events and run off; however, due to issues with the design of this particular structure, water was running beneath the concrete and eroding areas beneath the pan. The integrity of the structure was compro-mised due to the weakened and eroded supporting soil.

CDOT needed an effective solution to treat and repair the almost 800 foot long problem section of drain pan that would not only fill the voided areas, but also protect it against additional damage and structural failure that may also effect the safety of the adjacent highway.

A thorough evaluation of the site was conducted prior to design of the repair plan for the drain pan. It was determined that the more severe voids were located on the uphill slope area of the structure. Alternate solutions, including a flowable fill, were taken into account while determining the most effective way to treat the area. However, due to the advanced features of CST’s proprie-tary injection process, and the unique characteristics of the specialized expanding structural polymer, it was determined that filling the voided areas using this process would most effectively and most efficiently solve the problem. Injections were made directly through the drain pan, filling voids, and strengthening the supporting soils.

The entire stretch of affected drain pan was void filled and stabilized in four days without any disruption to traffic flow along the adjacent highway.

The treatment method allowed CDOT to extend the use life of the structure and avoid the expense of tearing out and replacing the structure.

The specifically designed repair not only eliminated the void space beneath the pan and strengthened the soils, but also provided protection to the structure against future erosion.

Repair costs came in under budget for this project.

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

Historic Structure Foundation Stabilization – Cody, WY

The Irma Hotel is a beloved historic land-mark in Cody Wyoming. Built in 1902 by William F. Cody, a.k.a. Buffalo Bill Cody. The “Irma”, named for Buffalo Bill’s youngest daughter is on the National Register of Historic Places.

Settlement had occurred on one corner of the structure due to a downspout terminating too closely to the rock foundation. The settlement had caused cracking of the exterior stone masonry and interior finishings of one of the hotel’s guest rooms. It was important to the owner to stabilize the foundation to prevent additional damage without disrupting patrons or having to close the business for a lengthy period of time. It was also important to the owner to repair the foundation without causing additional damage to the original stone foundation and masonry.

Owner Scott Darby contacted CST to evaluate the foundation settlement and provide a solution to repair the problem.

CST first performed a thorough site evaluation and survey of the hotel’s foundation and settlement.

An injection plan was designed. Injection depths and locations were determined and survey benchmarks placed.

The crew then placed probes into the foundation soils and installed high density structural polymer at the predetermined depths.
CST’s low pressure injection process is an ideal solution for historic structures. The polymer expands, filling voided areas and restores bearing capacity of the soil to support the structure and mitigate against future settlement.

CST completed all injections along the foundation in one working shift without need to close the business during repair.  Foundation soils were efficiently and effectively stabilized, protecting the historic structure against future settlement and damage.  The technology is performed without excavation and provides a fast, clean, and long lasting solution.

CST’s foundation stabilization and lifting technology is well suited for historic structures where high pressure grout or alternate methods may cause damage or alteration of the original structure.

CST’s foundation repair and soil stabilization technology helps preserve and protect the original integrity of historic structures.

Riverton Utah Commercial Void Fill and Soil Stabilization

In early February of 2018, a major water line break caused significant voiding be- neath the floor slab of a large commercial retail warehouse in Riverton UT. The pressure of the water was so great, in addition to causing large voids beneath the floor, it actually cracked the slab, and push water through the control joints in the concrete, flooding portions of the store. Scott Davis with Kleinfelder Engineering contacted CST concerning the damage, looking for an in situ solution to fill the voids. Soil testing performed after the water line break revealed that the soil compaction beneath the floor was good, but the voided areas would need to be filled. The solution would need to be performed without having to move permanently installed shelving units and merchandise and be completed without a lengthy closure for the business.

CST partnered with Tradesmithe Property Management and Kleinfelder Engineering to design an in situ repair plan to fill the voids and provide continuous , uniform subgrade support. The solution needed to provide a minimum of 6,000 PSF compressive strength of the soil and maintain dimensional stability for the life of the structure. CST’s in situ soil stabilization technologies employs a high density, expansive structural polymer injected through small holes directly through the floor slab and into the subgrade soils. The polymer, in it’s liquid state travels along finding voided areas and expands to fill and re-compact the compromised soil. Injection holes are very small and are filled with grout once repairs are complete. Once cured, the polymer reaches a much higher compressive strength that easily exceeded what was required for this project.

Once all voided areas were identified and marked, CST installed ESP material and completed void fill on a total area of 26,000 SQ FT.  All repair work was completed in 3 nights, allowing the business to stay open during the day.

Due to the highly advanced injection techniques and equipment, permanent shelving units and merchandise did not have to be moved in order to make the repairs.

The repair process efficiently and effectively restored compaction to the sub- grade soils and provided a solid solution to extend and preserve the useful life of the floor slab and structure.

CST’s polymer injection process does not require excavation and is environmentally friendly while providing fast, clean, permanent results.

  • Locate all voided areas and complete repairs without moving permanently installed shelving features and
    merchandise.
  • Permanently installed shelving, fix- tures, and appliances could not be moved during the repair.
  • No excavation required.
  • Environmentally friendly.
  • Little to no disruption to business.
  • Extends the useful life of existing slabs and structures.

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.

Jefferson High Foundation Settlement – Edgewater, CO

Concrete Stabilization Technologies, Inc. worked with General Contractor Saunders Construction, on the Jefferson High School Remodel project, to stabilize soils and lift slabs in nine classrooms, a hallway, and a bathroom.  The work included cutting L-shapes  in carpet as required for injection holes, drilling of holes, testing, injection to stabilize soil & fill voids, grouting injection holes, and re-gluing carpet and replacement of any damaged tiles caused by drilling.

The work was scheduled to allow approximately 10 days to complete.

By lifting one of the classroom slabs back to original, it also realigned the cabinets along a wall   in one of the classrooms which is one  added benefit we commonly see when doing this type of  repair:  doors open and shut properly, cracks in walls close up, shelving becomes level again, etc.

The project was completed in four days vs. the ten day window for the work.  The stabilization work was completed with minimal disturbance to the facility, in half of the allotted time and under budget!  A major advantage of the CST technologies is the non-invasive and fast, clean nature of the processes. Schools, Hospitals, Shopping Centers, and other Public Use buildings are typically repaired and put immediately back into use in a matter of days vs. weeks or months.  This makes an ideal solution for projects needing to be completed over Holiday and Summer breaks or during off hours with no loss of use.