144 / 2024-03-02 12:36:30

A parametric study of pile responses to side-by-side twin tunnelling in stiff clay

twin tunnelling,single pile foundation,parametric study,stiff clay

To gain new insights into single pile responses to side-by-side twin tunnelling in saturated stiff clay, a three dimensional coupled-consolidation numerical parametric study is carried out. An advanced hypoplasticity (clay) constitutive model with small-strain stiffness will be adopted. The effects of each tunnel depth relative to pile will be investigated by simulating the twin tunnels either near the mid-depth of the pile shaft or adjacent to or below the pile toe. It is found the second tunnelling in each case resulted in larger settlement than that due to the first tunnelling with a maximum percentage difference of 175% in the case of twin tunnelling near the mid-depth of the shaft. This is because of the degradation of clay stiffness around the pile during the first tunnelling. Conversely, the first tunnelling-induced bending moment was reduced substantially during the second tunnelling. The most critical location of twin tunnels relative to the pile was found to be the tunnels below the pile toe