A major technical challenge with shallow tunneling in urban areas is to limit settlements of the ground surface which may cause damage to buildings. The question of how much settlement will occur has largely been studied empirically in the past. However, as refinements in settlement control and construction techniques are developed it becomes more important to understand the mechanisms of these problems.;This thesis presents a comprehensive investigation of time-dependent effects due to the dissipation of excess pore pressures around tunnels. A finite element code is developed which allows simulation of tunneling in cohesive soil, explicitly taking into account pore pressure mobilization and dissipation in time.;An elasto-plastic soil model is used to provide a good representation of the stress-strain behavior of the clay, since it undergoes yielding as it moves into the tail void.;Parametric studies on tunnel construction in clay are performed using the finite element code. The effects of varying soil strength, tunnel liner stiffness, size of the tail void, and permeability of the soil are considered. Comparisons are made between finite element behavior and existing field data.;One particular aspect of ground response to tunneling and related activities which is only poorly understood is the effect of mobilization and dissipation of excess pore pressures in cohesive soil. This effect may produce delayed settlements which are larger in both magnitude and extent than those due to the tunneling operations themselves.;The results of these studies indicate that time-related consolidation effects around tunnels in cohesive soil are of great importance. Surface settlements and linear loads generally increase with time. The increase in settlements is large when flexible liners are used, soft soil conditions are present, or the tail void is large.
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