Behavior of Segmental Jacked Pipe Piles in Stiff Clay: Fid-Bau Portal

Behavior of Segmental Jacked Pipe Piles in Stiff Clay

Lutenegger, Alan J. / Seider, Gary L. / Brown, Joseph

Small diameter segmental jacked pipe piles are one option for underpinning lightly to heavily loaded structures to reduce settlement and even restore the structure to near original condition. In most cases, short sections of steel pipe are jacked into the ground through poor soils to achieve the desired load capacity from end bearing on a firm layer. The mass of the structure is used as the reaction to jacking. A study was conducted to evaluate the influence of end configuration on the installation jacking force and load behavior on jacked segmental pipe piles in a stiff overconsolidated clay. Four different configurations of the pipe end were tested: two closed ends (flush and oversized plate) and two open ends (no end plate and oversized ring). Plugging measurements were made of the open end piles during installation. Compression tests were conducted one day after installation to determine short-term axial capacity. The results show that the pile plugging of open end piles occurs very quickly and that substantial side resistance can develop for flush end pipes. Results of the site characterization, pile installation forces, and load tests are presented.