Abstract: At present, the studies of adjacent pile deformation caused by foundation excavation in transient case are common. Less attention has been paid to the influences of time behavior on the pile-soils interaction. The disturbed soils show the rheological properties during excavation. A two-stage method considering the soil visco-elasticity is proposed to obtain the time-domain solution for the interaction between adjacent pile and foundation pit excavation. On the first stage, based on Boltzmann visco-elastic model, a Mindlin’s time-domain solution is derived to analyze the influence of excavation on soil additional stress at the position of adjacent pile in visco-elastic foundation. On the second stage, a Pasternak’s two-parameter foundation model is adopted to simulate the interaction between pile and soils. A simplified time-domain solution of pile horizontal deformation is derived in consideration of rheological effects. Finally, the simulation results from finite difference software are compared to simplified time-domain solution with good agreements. The parameters of Boltzmann visco-elastic model (bulk modulus, shear modulus, viscosity coefficient), pile diameter, excavation depth, distance between pile and foundation pit and excavation size are analyzed to investigate the influences on pile deformation. It is shown that the presented simplified time-domain solution can reflect the influence of excavation on adjacent pile deformation and the development trend of pile deformation with time. It may provide certain theoretical basis for practical projects.

Key words: foundation pit engineering, pile, visco-elasticity, Boltzmann model, time-domain solution