Elevated Conveyor Support
Challenge
I.E.I. Barge Services planned for a new overhead conveyor system to extend from a proposed rail/truck receiving pit to two material handling buildings at the facility. The elevated conveyor system would include three new tower supports. A deep test boring completed for a previous project on the property identified intermixed layers of loose sand and medium stiff clay to a depth of 37 feet, underlain by dense sand to 40.5 feet. However, a varying soil profile and fluctuating groundwater conditions were anticipated due to the proximity of the Mississippi River. Deep foundations were specified to support the proposed conveyor towers.
Solution
Helical piles were selected as the ideal deep foundation solution. Four to eight helical piles were specified at each tower location to be cast within concrete pile caps ranging in size from 104 to 340 square feet. The helical pile configuration consisted of Model 288 (2.875-inch OD by 0.276-inch wall) hollow round shafts with an 8”-10”- 12” triple-helix lead section to support a design working compression load of 33 kips and a design uplift (tension) load of 1.1 kips. Standard extensions advanced the piles to depths from 59 to 89 feet to achieve torque-correlated ultimate capacities of at least twice the design working loads (FOS ≥ 2). The lead sections and extensions were hot-dip galvanized for corrosion protection. The piles were fitted with standard new construction brackets and cast into the pile caps.
Project Summary
Architect/ Structural Engineer: IIW
Geotechnical Engineer: Terracon Consultants, Inc.
General Contractor: I.E.I. Barge Services, Inc.
Certified Pile Installer: MidAmerica Basement Systems
Products Installed: (20) Foundation Supportworks HP288 Helical Piles, 8"-10"-12" Lead Sections, Installed Depths from 59 to 89 feet, Design Working Loads of 33 kips (compression) and 1.1 kips (tension)
