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Project |
Southern Illinois University - Altgeld Hall - Earth Retention Carbondale, Illinois |
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Contractor |
FASTEEL Foundation Solutions, Inc., St. Louis, MO |
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Classification |
State University |
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Total Piers |
41 Hollow Shaft Helical Piles and 26 Soil Nails |
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Completed |
December 2002 - 11 days to complete |
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Photo 1 - Initial Excavation |
FASTEEL® Foundation Solutions, Inc. in St. Louis was asked to construct an earth
retention system to provide lateral support of a vertical cut approximately 6-foot
tall by 116 lineal feet wide while supporting the old foundation and three-story
building. Other c o n t r a c to r s declined to bid o r attempt performing the
work, stating it was outside their expertise. |
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The earth retention system was comprised of soil nailing helicals and helical piles,
ULTrA brackets, steel wire fabric, reinforcement steel, bearing plates and a shot-crete
facing of
up to 18 inches. The first phase was to underpin the existing 106-year-old
Altgeld Hall. This is a three-story, solid masonry construction, with a stepped
footing of 3.5 feet thick at the base. Also adjacent to this vertical cut, FASTEEL®
was to install new construction piers to support the proposed foundation wall of
the addition. |
Photo 2 - Preparing to underpin the stone foundation |
Photo 3 - Installing the hollow shaft pier |
Here was our challenge: To install helical piers to support the existing foundation
wall. Because of the specifications of ¼” maximum deflection, it was important to
underpin the existing foundation w a l l , thus taki ng surcharge loads off the
soil and transferring the load through the pier shaft. Then to set pier ULTrA brackets
to grade, in conjunction with steel cage, reinforcing steel and pour a grade beam
at pier locations. (Grade beams were approximately 3'x3'x3') |
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The project’s general contractor would excavate approximately 58 lineal feet of
wall to a 6-foot cut. below the existing foundation. FASTEEL® laid out and installed
soil nailing helicals, using a mini-excavator. The installation process was field
monitored throughout the installation. FASTEEL® furnished a pump, operator and two
laborers to install the steel wire fabric and reinforcing steel, then set bearing
plates and applied approximately 12-18" layer of shotcrete. Time required to complete
the shot-crete wall was two days. Finally, we installed new construction piers to
support the proposed foundation wall of the addition. |
Photo 4 - Intermediate excavation |
Photo 5 - Installing the soil nails |
This phase of the construction was successfully completed ahead of our proposed
schedule, which gave time for the general contractor to complete other areas of
his project. |
Photo 6 - Soil nailing and new construction piers in place |
Photo 7 - Final Phase - applying shot-crete to walls |
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