SHIELD TUNNELING ADVANCEMENT SIMULATION USING 3D FEM CONSIDERING DISTANCE FACTOR AND ITS VALIDATION

A new approach of shield tunnel advancement for soil deformation calculation is presented using 3D finite element method. Applying step by step tunneling loads in this method, total soil deformation is calculated by summation of induced displacement from the first loading step to the current step deformation. In this approach, shield machine face distance from monitoring locations is taken as a factor which affects way of calculating soil displacement. If TBM machine face distance from the monitoring location is assumed to be less than a specific distance say “D”, drained condition is used to calculate soil deformation; on the other hand, if the machine face distance from monitoring location is more than “D”, undrained condition is used for soil deformation calculation. Additionally field data of an EPB shield tunneling site were gathered and used to investigate the validity of proposed approach.