Ground settlement trough due to DOT shield tunneling

Abstract

In this paper, the tunneling with a Double-O-Tube (DOT) shield for the construction of Taoyuan International Airport Access Mass Rapid Transit in Taiwan was introduced. The DOT shield machine and tunneling operation was summarized. Based on the field data, it was found the backfill grouting rate decreased with increasing tunnel depth. This was probably due to: at a deeper location, the pressure to close the tail void was greater, therefore high backfill grouting rate was hard to achieve. Eleven sets of field data collected from six cases indicated that, the maximum settlement due to DOT shield tunneling decreased with increasing tunnel depth. It was also found that the width of settlement trough increased with increasing tunnel depth.