Pressure Infiltration Characteristics of Foam for EPB Shield Tunnelling
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Infiltration of pressurised foam into saturated sand has been investigated in a laboratory setup that provides a comparable hydraulic gradient as in real tunnels. It appears that the permeability of sand for foam decreases as FER of the foam increases until a limit FER (approximately 15 for the foaming agent and sand used in this experiment). For higher FERs the permeability remains more or less constant. It was found that a ‘dry’ foam (FER = 20) is not essential for formation of a low permeable layer in the sand, even a ‘wet’ foam (FER = 5) can form a low permeable layer. When the discharge is less than that corresponding to the drilling velocity of a TBM, there will be no foam spurt and consequently no zone with low permeability. Without a low permeability plastering at the tunnel face the pressure applied through the foam will be less effective to stabilize the face.
Keywordsfoam EPB shield infiltration permeability FER
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The authors would like to acknowledge the scholarship funded by China Scholarship Council, the Mobility Fund of Ghent University, the University of Macau Research Fund MYRG2017-00198-FST and the Macau FDCT fund 193/2017/A3.
- Amoun, S., Sharifzadeh, M., Shahriar, K., Rostami, J. and Azali, S. T. (2017). Evaluation of tool wear in EPB tunneling of Tehran Metro, Line 7 Expansion. Tunnelling and Underground Space Technology, 61, pp 233–246.Google Scholar
- Bezuijen, A. and Schaminée, P. E. L. (2001). Simulation of the EPB-shield TBM in model tests with foam as additive. Proc. Int. Symp. on Modern Tunneling Science and Techn. Kyoto.Google Scholar
- Bezuijen, A. (2002). The influence of permeability on the properties of a foam mixture in a TBM. 4th Int. Symp. on Geotechnical Aspects of Underground Construction in Soft Ground – IS Toulouse 2002.Google Scholar
- Bezuijen, A. (2011). Foam used during EPB tunnelling in saturated sand, description of mechanisms, Proc. WTC 2011, Helsinki.Google Scholar
- Bezuijen, A. (2012). Foam used during EPB tunnelling in saturated sand, parameters determining foam consumption. Proceedings WTC 2012, Bangkok.Google Scholar
- Budach, C. (2012). Extended application ranges of EPB-Shields in coarse-grained soils. Doctoral thesis, Ruhr-Universität Bochum, Germany.Google Scholar
- Budach, C. and Thewes, M. (2015). Application ranges of EPB shields in coarse ground based on laboratory research. Tunnelling and Underground Space Technology, 50, pp 296-304.Google Scholar
- Condat Lubricants. (2015). New high-tech foaming agent for TBM. https://www.condatlubricants.com/product/sealant-foam-lubricanttunnel-boring/foaming-agents-epb/.
- Galli, M. (2016). Bochum Rheological characterisation of Earth-Pressure-Balance (EPB) support medium composed of noncohesive soils and foam. Doctoral thesis, Ruhr-Universität, Germany.Google Scholar
- Maidl, U., Pierri, J. (2014). Innovative hybrid EPB tunnelling in Rio de Janeiro. Geomech. Tunn. 7, 55–63.Google Scholar
- Merritt, A., Jefferis, S., Storry, R. and Brais, L. (2013). Soil conditioning laboratory trials for the Port of Miami Tunnel, Miami, Florida, USA. In: Proceedings of the ITA-AITES World Tunnel Congress in Geneva.Google Scholar
- Merritt, A. S. and Mair, R. J. (2006). Mechanics of tunnelling machine screw conveyors: model tests. Géotechnique, 56(9), pp 605–615.Google Scholar
- Peila, D., Oggeri, C. and Vinai, R. (2007). Screw conveyor device for laboratory tests on conditioned soils for EPB tunneling operations. Journal of Geotechnical and Geoenvironmental Engineering, ASCE, 133, pp 1622–1625.Google Scholar
- Talmon, A. M., Mastbergen, D. R., and Huisman, M. (2013). Invasion of pressurized clay suspensions into granular soil. Journal of Porous Media, 16, pp 351-365.Google Scholar
- Xu, T. and Bezuijen, A. (2018a). Pressure infiltration characteristics of bentonite slurry. Géotechnique. https://doi.org/10.1680/jgeot.17.T.026.
- Xu, T. and Bezuijen, A. (2018b). Analytical methods in predicting excess pore water pressure in front of slurry shield in saturated sandy ground. Tunnelling and Underground Space Technology, 73, pp 203–211.Google Scholar