A Simplified Design Procedure for Steel H - Piles in Areas of High Seismicity to Include the Effects of Pile Buckling

Section 1808.2.9 of the International Building Code states that certain types of soils called fluid soils (e.g., liquefied sands and bay mud) are not capable of resisting pile buckling and piles used in such soils should be designed as unbraced columns. This paper presents a unified approach for designing steel H-Piles in areas of high seismicity where soil liquefaction and/or loss of lateral support are design considerations. A general procedure for pile design is formulated based on governing codes, accepted practice, and relevant literature. The procedure is in compliance with the International Building Code , the AISC Seismic Provisions for Structural Steel Buildings , and the AISC LRFD Specification for Structural Steel Buildings . Using beam-column design provisions, interaction diagrams (φP n vs. φM n ) are developed for several hot-rolled H-Pile Sections that are permitted in areas of high seismic risk. The exclusion in this paper of some standard H-Pile sections is a result of local buckling instability as determined by limiting width-thickness ratios presented in the AISC Seismic Provisions for Structural Steel Buildings . Numerous interaction diagrams are developed for each pile size so that practical unbraced lengths resulting from nominal soil support afforded by marine clay and liquefied soil layers can be directly accounted for in the proposed design procedure. This paper provides a simplified approach for designing steel H-Piles to include the effects of pile buckling, the development of interaction diagrams needed for the simplified procedure, an overview of other code requirements for steel H-Piles in high seismic zones, and a practical application example.