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Lining response of twin tunnels affected by EPB shield operation
Author(s)
Suwansawat, S.
Date Issued
December 1, 2007
Type
Conference Paper
Abstract
In the Bangkok MRTA project, some parts of the tunnels were designed to run close to each other due to the limitation of underground space. To investigate the lining response when an EPB shield was driven very close to another tunnel, convergence bolts were installed to measure changes in the tunnel shape. The convergence bolts were observed relative to the advance of the second shield. Additionally, shield operational parameters were monitored to determine effects of shield operation on tunnel linings. It was found that the first tunnel lining was deformed during the passing of the second shield as the second tunnel can induce stresses acting on the first tunnel. The stresses can cause inward deflections in the tunnel lining particularly at the location between springline and invert. The deflection magnitude of the first tunnel appeared to be proportional to the face pressure and the grouting pressure levels of the second shield. This paper describes the behavior of tunnel lining as affected by the shield operation. © 2007 Taylor & Francis Group.
Citation
Proceedings of the 33rd Ita Aites World Tunnel Congress Underground Space the 4th Dimension of Metropolises, 2, 1261-1266, 2007