Abstract:

Shieldbored tunnels are often adopted in Taiwan's current airport MRT projects, power transmission projects, underground pipeline projects, sewer projects and many other projects in cobble/gravel stratum. However, the literature shows that studies on shieldbored tunnels in soils are more. The predicted formula for surface settlement trough of Taipei MRT was developed, while that in cobble/gravel stratum is less relevant. The progress of shield tunneling in cobble/gravel stratum and the increasing number of future applications show the importance of the research. In this paper, with the Taoyuan international airport MRT CU02A lot as an example, countermeasures to reduce the deformation of the ground through, including the backfill grouting in regular section, as well as strengthened backfill grouting, secondary grouting and grouting along shield machine in highrisk zone (such as boring underneath the taxiway zone) are presented. This paper studies the deformation behavior of the ground in regular section and highrisk section through the monitoring during construction and cross comparison of the results. It explores the effects of deformation control measures of shieldbored tunnel and the feedback of the construction information. Finally, this paper, based on the construction and monitoring data, tries to verify the design phase and describes the design and construction practices combined with the feedback.

Key words: cobble and gravel stratum, shieldbored tunnel, airport MRT system