Continuous Flight Auger Piles Are the Right Solution for 5600 S Pedestrian Bridge
Item #: 20240054
Item #: 20240054
CONTACTS
Implementing Organization: Region One
Champion: Brady Roberts
Implementation Lead: Ryan Maw, Gerhart Cole, Inc. ryanm@gerhartcole.com, 435-232-4984
Development Team:
UDOT
Region One - Brady Roberts, Trent Beck
Structures/Geotechnical - Jon Bischoff, James Corney
Consultants (Design)
Horrocks: Richard Hansen, Ben Nelson, Jake Orton
Gerhart Cole: Ryan Maw, Brian Garrett, Nick Langford, Ryan Cole, Travis Gerber
Consultants (Program Management)
Kimley-Horn: Lynn Iaquinta, Andy Sanford
Shannon & Wilson: Corbett Hansen
Contactor
Sand Ridge Constructors (joint venture with Granite and WW Clyde):
Anderson Showman, Bryan Griffith, Casey Green, Eric Wells, Scott Wiscombe
Subcontractor
Malcolm Drilling: Scott Chambers, Dave Vistaunet, and Matt Madsen
Article Written By: Ryan Maw
Innovation Council Liaison: Winston Inoway
Innovation Team Coordinator: Winston Inoway
STATUS
Implementation Date: Month June 1, 2024
Adoption Status: Fully Implemented
Adoptability Note: CFA piles might be the right solution for certain locations. Would this approach help your project?
APPLIES TO
Topic: Construction Practices
Organization(s): Structures
Job Role(s): Construction Engineer, ROW / Permits
Tags: active transportation, highway transportation, labor productivity, occupational safety, value of life, value of time, , inventions, civil engineering, construction, structures, construction safety, pedestrian safety, environmental quality > pollution > air, noise, public opinion, quality of life
On the I-15/SR-97 5600 South widening project in Region One, the project called for the construction of a pedestrian bridge over 5600 South. Due to the proximity of accessways, private residences, and utilities, as well as site soils, the use of driven piles and drilled shafts posed a number of project challenges, including the risk of vibration and settlement to adjacent infrastructure.
The Progressive Design-Build project team, including geotechnical and structures consultants, proposed using Continuous Flight Auger (CFA) piles for the bridge foundations. This was the first use of CFA piles on a UDOT project and required extra documentation and testing to meet approval.
CFA piles are created with the use of a hollow-tipped auger that maintains the stability of the excavation or hole. Once the hole is completed, the auger is withdrawn while a grout/concrete mixture is simultaneously pumped into the hole forming a pile. By pumping as the augers are withdrawn, the hole stability is maintained first with the casing and second with the grout mixture. Reinforcing steel cages are then placed while the grout is still wet.
Once the grout has set, there is no change to design, service life, or maintenance compared with alternative foundation systems. The CFA piles were tested using thermal integrity profiling methods and an adapted dynamic test method using a specialty frame and 49,000 lbs drop weight to demonstrate pile integrity and resistances.
The CFA piles provided multiple advantages for this project:
Minimal impact to adjacent property owners (within 20 feet of homes).
No impact to adjacent sidewalks, accessways, or school walking routes.
The work was completed safely without any incidents.
The foundation was constructed more quickly than using other methods (in total 36 CFA piles installed, and select piles tested, in about a week).
Saved money and demonstrated proposed CFA piles methods worked successfully.
If CFA piles were not used, multiple utilities would have been impacted and potentially required relocation.