Axial Load-Displacement Behavior ofAugered Cast-In-Place Piles and Pressure-Injected Footings

摘要

Augered cast-in-place (ACIP) piles and pressure-injected footings (PIF) aredrilled foundations that can develop increased capacity and stiffness because of theconstruction processes used to build them. To evaluate these increases, load tests areused to evaluate the overall axial load-displacement behavior, which then can begeneralized and compared with drilled shaft behavior. In this paper, the overall axialload-displacement behavior is examined using a database of 296 load tests developedfor ACIP piles and PIFs. Issues of extrapolation of load test results and interpretationof the “failure load” are examined. Consistent procedures are suggested to extrapolate(where necessary) and interpret the data. A consistent correlation is found betweenthe failure load interpreted by the slope tangent and L_1-L_2 methods. Results are comparedwith other drilled foundation types, and construction effects are discussed.