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Case Study 578-3aMysterious Settlement of Historic
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 Photo: Alan Broyles - Johnson City Press |
Description of Structure: The structure is a kitchen wing addition to a 200 year old residence located in eastern Tennessee. The addition was constructed in 1928. The footings and walls are constructed of limestone and measure 18 inches thick. The hand hewn wooden beams supporting the floor and rafters are attached with wooden pegs.
Distressed Observed: Settlement at the exterior wall opposite the original structure was nearly three inches. Separations of the walls and roof at the points of attachment to the original structure were nearly six inches. The gap at the kitchen ceiling was so large that one could easily see the sky from inside the house.
Cause of the Problem: The exact cause of the settlement is still a mystery. Some theories cite seismic activity or rock blasting at a nearby construction project as possible causes. After nearly 70 years, the underlying soils became unstable and lost compaction.
Repaired By: Average Pier Load: Ultimate Pier Capacity: Number of Piers: Amount of Lift: |
REMBCO Engineering, Inc. Knoxville, Tennessee 40,250 pounds 85,000 pounds 10 2-3/4 inches |
| REMBCO Engineering chose Atlas Resistance Piers as THE Solution for this structure, which is listed in the National Register of Historic Places. Ten Atlas 2-Piece Piers were installed on three sides of the kitchen as shown on the plan shown at right. The piers were driven to a suitable bearing stratum at an average depth of 32 feet. The average lifting force was 40,250 pounds. Restoration was nearly 100 per cent! Only replacing trim molding inside and mortar replacement between the house and the addition were required to complete the project. |
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Photo: Alan Broyles - Johnson City Press |
SUCCESS! The Atlas Pier Bracket is mounted below the footing and the pier is gently installed to a suitable bearing stratum. Each Atlas Resistance Pier is tested before the structure is lifted. The photo at left shows a REMBCO Engineering technician at the lifting control panel. The technician controls all ten jacks for a uniform and careful restoration to as close to the original elevation as the construction permits. Once the structure is restored, high strength pins are inserted into the Atlas Pier bracket to maintain the desired elevation. Then the hydraulic lifting jacks are removed. |
THE Solution:
ATLAS RESISTANCE PIERS
The photograph below shows a worker attaching the hydraulic line to the ram that will raise and restore the structure. On this project, all hydraulic rams were connected through a control panel where the technician monitors and controls the lift at each pier. This method insures even and gentle support as the structure is restored. |
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Photo:
Alan Broyles - Johnson City Press |
The photo above
shows the structure in the settled condition, notice the large
separations at the roof, and where the addition joins the original structure.
After lifting the structure, the separations are nearly closed and the floors restored.
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Email: info@atlassys.com