Case study on the application of shield TBM in the gravel layer with high water pressure underpassing the Han River

Abstract

Recently, shield TBM is widely used for shallow tunnel, super long tunnel, downtown area where blasting method cannot be applied, as well as subsea and riverbed tunnels. A case study on the design and construction for shield TBM tunnel which is the construction case of tunnel underpassing the Han River would be explained in this paper. TBM tunnel on this site was designed on the basis of the results of preliminary geotechnical investigation. The dimension of tunnel is 45m of maximum depth, 15m of maximum water depth and total length is 1,497m. Tunnel diameter is 3.01m, equipment type is EPB and segment thickness is 20cm. In this case, the advance rate of shield TBM fell short of its designed advance rate due to the geological condition which is consist of multiple layer(i.e., high water pressure layer including sand and gravel layer) and is different with the designed condition. As a result of efforts to overcome the unexpected difficulty, the construction was completed safely securing the stabilities of the tunnel. On this paper, application of shield TBM in the gravel layer with high water pressure case will be introduced based on the data for solution to overcome the difficulty in tunnel excavation.