Case Study: Design and installation of Large Diameter Open-Ended Pipe Piles for DOT Project: Lessons Learned-PPT Presentation

PPT Presentation

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The case study describes the design and installation of large-diameter, open-ended pipe piles for a constrained Illinois DOT project. The site layout was complicated by nearby highways, multiple railroad tracks, Missouri Avenue, a deep-well facility, and relocated Route 3 land bridges.<br /><br />During construction, testing at Pier 3, Pile 4 indicated that the pile’s estimated capacity was substantially below the original design requirement. The pile was estimated to provide an ultimate capacity of 1,250 kips and a factored resistance of 813 kips, compared with a required nominal bearing of 3,006 kips. The pile group’s original design load was 1,654 kips under service conditions and 2,012 kips for the seismic event.<br /><br />Several remedies were considered, including removing the pile, drilling it out and converting it to a drilled shaft, adding piles and enlarging the pile cap, or installing a larger-diameter pipe pile. The selected solution involved an additional 5-foot-diameter pipe pile, designed and installed to supplement the foundation.<br /><br />Final testing showed a GRL-estimated ultimate capacity of 3,733 kips and factored resistance of 2,426 kips. These results exceeded the project’s total pile design loads of 1,941 kips for service conditions and 2,747 kips for seismic loading, while closely approaching the specified nominal and factored resistance targets.<br /><br />The presentation’s key lesson is the importance of responding to field-discovered capacity shortfalls with a practical foundation modification that accommodates demanding site constraints and verifies performance through testing.

Keywords

large-diameter pipe piles

open-ended pipe piles

Illinois DOT

pile capacity testing

foundation modification

seismic loading

pile design loads

GRL estimated capacity

constrained site conditions

pile cap enlargement