This is a
view of the job site where workers are finishing the new concrete floor. The ATLAS
RESISTANCE PIERS provided support to the existing structure during excavation.
Description of Project: The existing structure houses the
Bell South Central Office. Due to growth in the area, an addition to the structure was
planned. The new structure has a finished floor elevation approximately 6’ - 8’
below the footings of the existing structure. The designer had to address the problem of
supporting the existing structure while the soil was removed adjacent to the footing.
Also, the owner needed to maintain operations in the existing structure without disruption
from movements or vibrations during construction of the addition.
Description of Design: The engineers recommended support of
the existing structure using ATLAS RESISTANCE PIERS. Suitable bearing for the piers
was found at 59.5 feet below the existing footings. The concern was the strength of the
exposed pier during excavation and construction. The stiffness of the pier was enhanced in
this area by installing a pier sleeve over the 4 inch diameter pier pipe. The soil from
below the existing structure was retained during the excavation by steel reinforced
concrete retaining walls. This wall was constructed after each 18 inches of excavation.
Technicians are installing the AP2P-4000M Atlas Resistance Piers to
the existing structure. The pier spacing was designed by the engineers to load each pier
to 30,000 pounds.
Atlas
Resistance Pier Summary
Design Engineer: Parsons Infrastructure & Technology Group,
Atlanta, Georgia
Installed By: Atlas Piers of Atlanta -- Alpharetta,
Georgia
Atlas Resistance Pier Product: AP2P-4000M -- ATLAS
2-PIECE MODIFIED
RESISTANCE
PIER
Number of Resistance Piers: 15
Average Drive Force: 60,000 pounds
Average Working Load: 30,000 pounds
Factor of Safety: 2 : 1 [100% above working load]
Average Depth: 59’ - 6" |
The plan view to the right shows the general layout of the 15 Atlas
Resistance Piers on the structure.
Below is a cross
sectional sketch of the Atlas Resistance Pier installed to the existing structure
and the relationship of the new slab to the original structure.
After the ATLAS RESISTANCE PIERS are installed to the load bearing
stratum, each pier is tested to a load of 60,000 pounds. Each pier then has 14 feet of
4-1/2 inch diameter sleeve installed over the pier. A working load of 30,000 pounds then
applied to the pier and the pier pins are installed.
After excavating approximately 18 inches of soil, steel reinforcing is
installed and a wall is cast to retain the soil mass under the existing structure.
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SUCCESS!
These photographs show the completed shoring and support
project. The existing structure is fully supported and the soil mass under the structure
has been retained. The floor slab for the new addition has just been cast.
Atlas Resistance Piers…
THE
SOLUTION!
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