Experimental Curvature and Moment Response of Pile Foundations: Comparison with p-y Predictions-Video

Video Transcription

Video Summary

The study evaluates whether conventional p-y analysis accurately predicts piles’ lateral response. Researchers tested three instrumented pile types—reinforced concrete, concrete-filled steel pipe, and steel pipe—in very loose sand at a large soil-pit facility. They compared measured load-displacement and internal response with p-y calculations.<br /><br />For all three piles, p-y analysis overpredicted lateral load and initial stiffness at working displacements, yet slightly underpredicted maximum resistance. It also predicted curvature and moment roughly two to four times higher at a given displacement. Predicted moment depth was generally accurate, but moment-profile shapes differed: calculations showed sharper peaks and reverse curvature that measurements did not.<br /><br />Large craters and soil densification developed around the piles. The researchers suggest standard p-y relationships may not capture this behavior in very loose sand. They caution that results are specific to the tests and do not invalidate p-y analysis generally. Accurate conversion of measured curvature to moment also requires an appropriate cracked moment-curvature relationship.

Keywords

p-y analysis

lateral pile response

very loose sand

instrumented piles

load-displacement behavior

pile moment-curvature