Effect of joints on p– y behaviour of laterally loaded piles socketed into mudstone

Abstract

Secondary structures such as joints play an important role in determining the p–y behaviour and the corresponding pile head load-deflection response of laterally loaded piles socketed into jointed rock mass. In this study, a comprehensive numerical modelling was undertaken for piles socketed into mudstone rock using three-dimensional distinct element code, 3DEC. Two full-scale pile load tests results were employed to validate the numerical model and to derive the p–y curves for the mudstone. The validated numerical model was subsequently extended to study the effect of various joint sets on both the p–y and pile head load-deflection behaviour. It was found that an increase in the number of joint sets weakens the p–y behaviour of the rock mass and the corresponding pile head load-deflection response considerably. In addition, it was found that the existing p–y criteria were inadequate to capture the variation in the p–y response of the rock when physical joint sets were incorporated.