A case study of monitoring and analysis of ground settlement caused by tunnelling of stacked twin tunnels for underground metro\nline construction through the densely populated area using the slurry pressure-balanced TBM is presented. Detailed ground\nsettlement monitoring was carried out for the initial stage of down-track tunnelling in order to estimate trough width factor and\nvolume losses including face, shield, and tail losses. In addition, using the gap model, prediction of volume loss and ground\nsettlement was carried out with consideration of the ground condition, TBM configurations, and actual operation data. The\npredictions of the gap model were compared with the observed results, and adjustment factors were determined for volume loss\nestimation. The adjusted factors were applied to predict ground settlement of the up-track tunnel, and its results were compared\nwith the field measurements.
Loading....