March 2017 Fully Assembled Statnamic Test Structure
June 2017 CZM and SoilMec
July 2017 Pouring concrete while continuing to drill
July 2017 Load test for Auger Cast Pile
July 2017 CZM EK250 drilling
August 2017 SoilMec SR75 Drilling with polymer slurry
January 2018 Air Lifting the bottom of the shaft
January 2018 First tank slab preparing to be poured
January 2018 Aerial View of Completed Caissons
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Location
Baltimore, MD
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Duration
March 2017 - December 2017
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Owner
Baltimore City
Wagman’s Geotechnical Construction group installed 372 caissons to support two, 6.5M gallon prestressed concrete tanks at Guilford Reservoir, located in Baltimore, Md. The project’s goal was to replace the open reservoir with two underground tanks that supply the city of Baltimore with tap water.
Polymer slurry was used to maintain sidewall stability during the caisson installation. The drilled shaft bottoms were held to stringent specifications for cleanliness. Sediment from the bottom of the shaft was removed using an airlift system and visually checked with a shaft inspection device (mini-SID), before concrete could be placed. After completion, the site was backfilled and the land above the tanks was transformed to a new Baltimore City Park.
Key Challenges & Project Details
- The capacity of the piles were verified by four Statnamic Load Tests at 200% of the design load (1,250 ton load), four tensions tests, and four lateral load tests.
- Drilled shafts were 42” in diameter and varied in depth from 40’ to 80’ with a total drilled length of over 20,000 linear feet.
- Termination criteria for the drilled shafts were based on 18’ of decomposed rock or a 2’ rock socket in gneiss.