Design of Jet Grouted Excavation Bottom Plugs
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 142, Issue 7
Abstract
A methodology for cost-effective design of jet grouted water-sealing bottom plugs is presented in this paper. These massive barriers, made of partially overlapping jet grouted columns, are required to ensure temporary waterproofing to excavation areas and adequate uplift resistance against water loads. Therefore, the proposed calculation procedure simultaneously focuses on the structural performance and continuity of the plug. The design may be optimized by considering the possibility of reducing column length, performing injections only in the lower part of the plug, and leaving the upper part of the plug untreated. The reduction in column length may then result in a very slender slab, and a structural check has to be performed to avoid tension fracturing or overall structural collapse. Additionally, in spite of strict controls, jet grouted columns are never perfectly cylindrical or exactly aligned along their prescribed position, and thus the plug may present imperfections. Statistical evaluation of defects with experimental data from different field trials and their simulation with the Monte Carlo method shows that the imperfections are less relevant for the structural performance of the plug, but must be carefully taken into account in the analysis of seepage. Imperfections have been thus introduced in the structural analysis by means of partial factors evaluated from probabilistic analysis. The latter calculation provides a rule to control the effects of incomplete watertightness of the plug. The introduced relations are expressed with design charts.
Get full access to this article
View all available purchase options and get full access to this article.
References
Arroyo, M., Gens, A., Croce, P., and Modoni, G. (2012). “Design of jet-grouting for tunnel waterproofing.” Proc., 7th Int. Symp. on Geotechnical Aspects of Underground Construction in Soft Ground, TC28 IS Rome, G. Viggiani ed., Taylor & Francis Group, London, 181–188.
Burland, J. (1973). “Shaft friction of piles in clay—A simple fundamental approach.” Ground Eng., 6(3), 30–42.
CEN (European Committee for Standardization). (2004). “Eurocode 7—Geotechnical design.” EN 1997-1, Brussels.
Croce, P., and Flora, A. (2000). “Analysis of single fluid jet-grouting.” Geotechnique, 50(6), 739–748.
Croce, P., Flora, A., and Modoni, G. (2001). “Experimental investigation of jet grouting.” Proc., ASCE Conf. 2001 a GeoOdissey, ASCE, Reston, VA, 245–259.
Croce, P., Flora, A., and Modoni, G. (2014). Jet grouting, CRC Press, Taylor & Francis Group, Boca Raton, FL, 284.
Croce, P., and Modoni, G. (2002). “Numerical modelling of jet-grouted foundations.” Proc., 5th European Conf. on Numerical Methods in Geotechnical Engineering, European Regional Technical Committee (ERTC7), Paris, 453–458.
Croce, P., and Modoni, G. (2005). “Design of jet grouting cut-offs.” Ground improvement, Vol. 10-1, Institution of Civil Engineers, London, 1–9.
Eramo, N., Modoni, G., and Arroyo Alvarez de Toledo, M. (2012). “Design control and monitoring of a jet grouted excavation bottom plug.” Proc., 7th Int. Symp. on Geotechnical Aspects of Underground Construction in Soft Ground, TC28 IS Rome, G. Viggiani, ed., Taylor & Francis Group, London, 611–618.
Evangelista, A., Feola, A., Flora, A., Lirer, S., and Maiorano, R. M. S. (2000). “Numerical analysis of roof failure mechanisms of cavities in a soft rock.” Proc., Inter. Conf. GeoEng 2000, Vol. 2, Technomic, Melbourne, Australia.
Flora, A., Lignola, G. P., and Manfredi, G. (2007). “A semi-probabilistic approach to the design of jet grouted umbrellas in tunnelling.” Ground Improv., 11(4), 207–217.
Flora, A., Lirer, S., Lignola, G. P., and Modoni, G. (2011). “Mechanical Analysis of jet-grouted supporting structures.” Proc., 7th Int. Symp. on Geotechnical Aspects of Underground Construction in Soft Ground, Taylor & Francis Group, Boca Raton, FL.
Flora, A., Lirer, S., and Monda, M. (2012). “Probabilistic design of massive jet grouted water sealing barriers.” Proc. IV Int. Conf. on Grouting and Deep Mixing, L. F. Johnsen, D. A. Bruce, and M. J. Byle, eds., Vol. 2, ASCE, Reston, VA, 2034–2043.
Flora, A., Modoni, G., Lirer, S., and Croce, P. (2013). “The diameter of single, double and triple fluid jet grouting columns: Prediction method and field trial results.” Géotechnique, 63(11), 934–945.
Lignola, G. P., Flora, A., and Manfredi, G. (2008). “A simple method for the design of jet grouted umbrellas in tunnelling.” J. Geotech. Geoenviron. Eng., 1778–1790.
Meyerhof, G. G. (1976). “Bearing capacity and settlement of pile foundations.” J. Geotech. Eng. Div., 102(GT3), 195–228.
Modoni, G., and Bzòwka, J. (2012). “Design of jet grouting for foundation.” J. Geotech. Geoenviron. Eng., 1442–1454.
Modoni, G., Croce, P., and Mongiovì, L. (2008). “Theoretical modelling of jet grouting.” Géotechnique, 56(5), 335–347.
Ochmański, M., Modoni, G., and Bzòwka, J. (2015a). “Numerical analysis of tunnelling with jet-grouted canopy.” Soils Found., 55(5), 929–942.
Ochmański, M., Modoni, G., and Bzòwka, J. (2015b). “Prediction of the diameter of jet grouting columns with artificial neural networks.” Soils Found., 55(2), 425–436.
Shen, S., Wang, Z., Yang, J., and Ho, C. (2013). “Generalized approach for prediction of jet grout column diameter.” J. Geotech. Geoenviron. Eng., 139(12), 2060–2069.
Sondermann, W., and Toth, P. S. (2001). “State of the art of the jet grouting shown on different applications.” Proc., 4th Int. Conf. on Ground Improvement, Finnish Geotechnical Society, Helsinki, Finland, 181–194.
Vanmarcke, E. H. (1983). Random fields: Analysis and synthesis, MIT Press, Cambridge, MA, 382.
Van Tol, A. F. (2004). Lessons learned from jetgrouting at a tunnel project in the Haghe, A. Dhouib, J. P. Magnan, and P. Mastat, eds., LCPC, Paris, 321–331.
Van Tol, A. F., Koster, S., Ramler, J. P. G., Verruijt, A., and Vrijling, J. K. (2001a). “Imperfections in jetgrout layers.” Proc., 15th Int. Conf on Soil Mechanics and Geotechnical Engineering, Vol. 3, Balkema, Rotterdam, Netherlands, 1883–1886.
Van Tol, A. F., Van Riel, A. J. E., Vrijling, J. K. (2001b). “Towards a reliable design for jetgrout layers.” Proc., 15th Int. Conf. on Soil Mechanics and Geotechnical Engineering, Balkema, Rotterdam, Netherlands, 1887–1890.
Viggiani, C., Mandolini, A., and Russo, G. (2012). Piles and pile foundations, Spon Press, Abingdon, U.K., 278.
Information & Authors
Information
Published In
Copyright
© 2016 American Society of Civil Engineers.
History
Received: Jul 6, 2014
Accepted: Sep 23, 2015
Published online: Mar 7, 2016
Published in print: Jul 1, 2016
Discussion open until: Aug 7, 2016
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.