Dynamic response of large diameter, concrete‐lined vertical shafts under external and seismic excitation

Abstract

AbstractThis article proposes a novel numerical model of the dynamic response of large diameter, concrete‐lined circular shafts, embedded in transversely isotropic soils. Excitation is given as time‐harmonic external loads applied to the base of the shaft, or vertically propagating, time‐harmonic pressure waves. The concrete lining is modeled with finite annular plate and cylindrical‐shell finite elements, while the contact tractions at the shaft–soil interface are modeled within a boundary elements framework. The response of the coupled system is obtained by imposing rigorous continuity and equilibrium conditions at the interface. The model yields accurate representation of the energy exchange between shaft and soil, as well as energy propagation through the soil as an unbounded medium. Original numerical results are presented on the response of the shaft and lining for selected geometric and constitutive parameters, frequencies and type of excitation, and anisotropic soil constitutions.