Project Summary:
Project: Milwaukee Substation
Location: NE Corner E. 26th St. & E. G St., Tacoma, WA
Owner: Tacoma Power
General Contractor: W.M. Dickson
Type of Pile: Wall Steel Pipe
Number of Piles: 18
Pile Depth: 55’ Average
Pile Capacity: 75 Tons
Pile Note: Pile filled with 4,000 PSI High strength grout and rebar cage for connection to foundation
Pile Hammer: APE Model D19-32 & 8’X26” Leads
Project Overview:
The new power substation upgraded the electrical capacity in the industrial are of Tacoma. McDowell NW was selected as a subcontractor for the placement of driven steel pipe piles.
Each pile was driven to approximately 55 lineal feel to achieve a design capacity of 75 tons. Once all 18 piles were placed and cut off to the provided elevation, McDowell NW filled the interior of the piles with high strength 4,000 PSI grout. Each pile consumed only about 1/3 yards of grout as the design called for a welded interior splice 14’ below top of the pile. Once the grout was placed a small top cage was inserted into the fresh grout and set to elevation. This cage formed the connection between the piles and substation foundation.