City of Buffalo WY Swimming Pool Void Fill Soil Stabilization

Problem

The City of Buffalo Wyoming’s public pool had experienced large amounts of water loss due to leaks in the main fill lines beneath the pool. Cracks in the concrete floor of the pool had also contributed to the water loss.

The leaks were causing ponds of water to develop beneath the pool, weakening base soils and this massive structure’s support system.

The City needed a solution that would seal the leaks in the main lines and underseal the floor of the pool to stop water loss.

Because of the large size, tearing out the concrete to repair the leaks would be extremely expensive and would cause major disruption for the public with a lengthy closure.

The City was looking for an in situ repair that would seal the leaks, stabilize base soils and allow the pool to be returned to service quickly.

Solution

CST partnered with City of Buffalo Public Works Director Les Hook, and department staff to design an in situ repair to seal the leaks, stabilize and void fill the soils to support the pool.

Through a thorough investigation of the pool, it was determined that the ponding water was mainly collecting beneath the deeper end.

Injection holes were drilled, and the crew installed expanding structural polymer, starting at the shallow end, and working towards the deeper end of the pool.

The injection pattern was carefully designed to only void fill and underseal the bottom of the pool without lifting any of the concrete.

As injections were made, water was displaced and pushed out from beneath the pool and the saturated support soils.

Result

A total of 30,454 square feet area was successfully void filled and under sealed in a matter of a few days using CST’s expanding structural polymer injection technologies.

The repair did not require any excavation and the pool was immediately available to be refilled and put back into use following completion of CST’s polymer injection process.

The City saved thousands of dollars avoiding a rip out and replace scenario.

The hydro-insensitive characteristics of CST’s expanding structural polymer is ideal for rehabilitating leaking infrastructure. The Zero Excavation repair process is an ideal solution for repairing water lines, sewer connections, dams, inlets, irrigation structures, manholes and ground water cutoff walls. The high ten-sile strength of the material mitigates against channeling and is an ideal void fill and soil stabilization solution.

Challenges

  • Design a cost effective repair solution to void and seal beneath the pool without tearing out the massive con-crete floor.
  • Complete repairs efficiently without major disruption to the public or a lengthy closure.
  • Stay within the City’s maintenance budget.
  • Benefits

  • Zero Excavation, in situ repairs.
  • Highly effective soil stabilization, void fill, and undersealing process.
  • Hydro-insensitive material works well in saturated environments.
  • High tensile strength mitigates against erosion and channeling.
  • 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

    Mine Shaft Head Frame Footer Foundation Stabilization

    The head frame support leg foundation on one of the Tronox Alkali Corporation mine shafts had experienced settlement. As a result, movement of the footings had caused the head frame and shaft bucket to shift from center. The issue was discovered as crews and equipment were being lowered and retrieved from the mine shaft.

    Tronox Mine Foreman Todd Jackson contacted John Eddins, P.E. with JFC Engineers and Surveyors to investigate the problem. The goal was to find a solution that would effectively align the shaft and mitigate the issue of potential future tilt or settlement.

    Stabilizing the foundation of the head frame support and correcting the tilt to safely allow mine crews to use the equipment to access the mine shaft was critical.

    JFC Engineers contacted CST to help deter-mine the best solution to stabilize and realign the structure.

    CST partnered with JFC Engineers and performed a thorough site investigation. It was determined that the back leg of the head frame foundation would be treated using the Uretek Technologies to stabilize, lift, and realign the structure.

    Dynamic Cone Penetrometer tests were performed to determine the condition of soils below the frame’s legs. The tests and analysis revealed that the soil would need to be treated at two depths to lift and to stabilize the soils to assure no future settlement would occur. Injections were made at two depths under the foundation and at the toe of the foundation to mitigate potential slide or settlement in the soils. The treatment was to obtain the target realignment of the structure and the foundation stabilization with minimal disruption to the structure or operations.

    Injection probes were placed through the asphalt and into the soils at depth. Injections were made while closely monitoring elevations for movement.

    The mine shaft footer foundation was stabilized and the shaft frame vertically realigned. Due to the surgical precision of the injection process, no additional stress to the structure or horizontal movement occurred during the lift. Voids were eliminated beneath the footings, ensuring a strong and stable base to support the heavy load.

    The project was completed with minimal disruption and without having to take the equipment off line during the repair. The equipment was immediately put back into use with all repairs done in only two shifts. Most importantly, stability was restored quickly and efficiently, extending the safe use-life of this industrial structure.

    “The project was well planned and executed. The back leg foundations were lifted to the established target elevations which brought the head frame structure to verti-cal plumb. The client expressed their ap-preciation and satisfaction with the results” -John Eddins, P.E., JFC Engineers & Surveyors

    CHALLENGES
    Stabilize the soil beneath this large piece of equipment without having to take the shaft offline or deconstruct the head frame.
    Correct the tilt of the head frame to bring the shaft bucket operation back to center.”

    BENEFITS
    In Situ, Fast, No-Dig Process
    Ability to Lift Heavy Loads with Surgical Precision
    Long Lasting Repair
    Extends Use Life of Existing Structures

    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.

    Crescent Electric Supply – Gillette, WY

    Structure Characteristics: The building is a single story structure approximately 80 feet by 125 feet in size and consists of wood post and beam framing, such as a pole building. The walls are constructed of wood posts, embedded in concrete piers at approximately 8 feet on center. The posts provide the vertical and lateral support for the walls and roof. The roof is framed with preengineered wood roof trusses. The floor of the building consists of a 6 inch thick reinforced concrete slab on grade. A septic tank and a leach field are situated along the west side of the building.

    Problems That Prompted Repair: The building and concrete slab on grade were experiencing settlement. The settlement had caused cracks in the concrete slab on grade and interior finishes of the office area of the building. The majority of settlement occurred along the west side of the building and the concrete slab on grade in the warehouse were cracked the entire length of the building. Cracking ranged 3 to 8 feet east of the west wall. A slab construction joint existing in the center of the building and spans north/south. The joint appeared to have separated as a result of the slab settlement along the building.

    Inspection/Evaluation Methods: A structural Observation and Geotechnical Soil Study were performed. Field investigation also performed with the use of a Dynamic Cone Penetrometer (DCP). The primary purpose of this tool is to locate the weak zones in the soils and quantify the comparative degree of ground densification improvement achieved by the deep injection process, as exhibited by the increased number of percussive blows required to penetrate the treated soil mass, when compared to a pre-injection test performed within the confines of the treated mass.

    Test Results: The geotechnical study and structural observation indicated that the soils underlying the foundation and concrete slab on grade consisted of soft clays with considerably high moisture content. These soils are notorious for settlement and collapse upon wetting. It was determined that the settlement had high potential to continue if the problem was not addressed. Separation of the slab joint was determined to have been caused by the settlement of underlying soils. DCP Test results indicated weak soils at depths of 7 feet.

    Causes of Deterioration: Deterioration was caused by a leak from a collapsed water tank in 2008 west of the building, effluent from the septic system, surface runoff, or a combination of these influences. Soft clay soils surrounding and beneath the structure and slab contributed to the settlement and associated damaged slab and interior finishes of the building.

    Repair System Selection: Selection of the repair system was based on recommendations resulting from structural evaluation of the building. Due to the soil conditions and probability of future settlement, “Deep Injection”, using expanding structural Geo-Polymer, was chosen for correcting the settlement issues.
    Site Preparation: Penetrometer testing was performed and reviewed. Mapping of the warehouse floor was completed. Profiles for settlement and finish target elevations were performed.

    Demolition Method: No demolition of the existing concrete slab on grade was necessary due to
    the utilization of the “internationally patented Geo-polymer injection system”. All soil remediation work was completed “In Situ”.

    Surface Preparation: Surface preparation of the slab, and soil surrounding the outer perimeter of the building, prior to injecting was unnecessary. This is due to the unique nature of the expanding Geo-Polymer technology utilized. Minimal cleanup of the joint area was performed before epoxy was injected and caulking repairs were performed in the west joints and wide joint in the center of the warehouse. The crack repair and joint sealing was performed in the floor slab. Cracks were mechanically routed and gravity fed structural epoxy was injected into the cracks. Caulking of the joints was completed using a urethane sealant as specified by the engineer. Approximately 136 linear feet of cracks and approximately 124 linear feet of control joints were primed and caulked.

    Application Method Selection: Repairs required utilization of a specialty technique. The foundation type (posts embedded in shallow concrete piers) does not lend itself well to helical pier stabilization. Stabilization of the underlying soils, individual concrete piers, and the concrete slab on grade itself needed to be modified in order to arrest future settlement. Therefore, the best method of application and method of repair was determined to be the injection of expanding structural Geo-Polymer.

    Repair Process Execution: Initial testing of the soils were performed and analyzed to determine injection depths necessary to stabilize the underlying soil structure. Areas to be addressed were mapped and injection ports were prepared beforehand to accommodate frozen soil conditions at the time of repair. The injection of the patented Geo-Polymer material was used to penetrate deeply into the sub grade at depths of an estimated seven feet. Voids beneath the slabs were filled, and slabs lifted back to original elevations. Sub grade soils were stabilized using this Internationally Patented Technology. Deep Injection permanently altered the soil structure, thus stabilizing and preventing future settlement. Once soils were treated, the slab joints were sealed and caulked with epoxy as specified by the project engineer.

    Structural floor repair: Sub contractor, gravity fed low viscosity epoxy into the floor cracks to re- establish the original monolithic strength.
    Control joint sealants: Sub contractor mechanically cleaned the sides of the existing control joint and caulked with urethane primer and sealant.

    Unforeseen Conditions Found: The work was performed in January which added concern for frozen ground and cold temperatures. The settlement originated below frost line. The Project Superintendent made additional efforts to keep equipment warm. The exothermic reaction of the Geo-polymer materials provided further protection against frozen conditions.

    It was decided to perform the work on the client’s preferred schedule if possible. One of the unique characteristics of the Geo-Polymer is that it will not freeze during injections (it is not a water based material). Since unit weight was minimized and polymer did not add burden to weakened sub- grade, frozen ground and cold temps did not interfere with the work schedule.

    Special Features and benefits of Geo-Polymer Deep Injection Repair Process:

    • Eliminated cause of settlement and future potential settlement resulting from the water spill.
    • Raised building and slabs to original elevation.
    • Saved concrete slab, and interior finish from further damage.
    • No downtime to business, timely, safe, clean.
    • All work done from above ground without excavation, In-Situ.
    • The Business was able to remain fully open during repairs with very little disruption to activities.
    • Floor sub-grade was restored to give full support for heavy forklift traffic.
    • Structural repair of floors was completed with full co-ordination of warehouse use.
    • Project was completed using permanent and economical, “Deep Injection” of Geo-Polymer.