ABSTRACT


To gain new in sights in to single pile responses to adjacent excavations in soft ground, three ' dimensional numerical parametric studies are carried out. An advanced hypoplastic (clay) constitutive model which takes account of small - strain stiffness is adopted. The effects of excavation depths (i.e., formation level) relative to pile were investigated by simulating the excavation near the pile shaft (i.e., He/Lp=0.67), next to (H/ Lp=l.00) and below the pile toe (H/ Lp=l.33). The model parameters are calibrated and validated against measured results in geotechnical centrifuge modelling reported in literature. It is found that the pile responses to excavation depend upon formation level of the excavation as well as the embedded depth of the wall. With different wall depth each case, the, lateral displacement and bending moment in the pile at the same stage of the excavation was different in the three cases. Among the three cases, the excavation in case of H/ Lp=I .33 resulted in the largest pile settlement (i.e., 7.6%dp). On the other hand, the largest pile deflection was induced in case of H/Lp=0.67. On contrary, insignificant bending moment and changes in axial load distribution induced i n the pile on completion of the excavation in each case. The study suggests that the effects of excavation on a pile can be minimized by increasing thickness of diaphragm wall, props stiffness and embedded depth of the wall.