Prediction of jet grouting diameter in Swedish soil conditions

Abstract

Soil improvement by jet grouting has been used extensively in continental Europe and Japan, and its use has gradually increased in Scandinavia. The most frequent practical use of Jet Grouting in Sweden is water sealing of sheet pile wall excavations. In this application the diameter of the jet grouted columns governs the design, and the mechanical properties of the columns are of less importance. The existing methods for estimation of jet grouted column diameter have been developed in geological conditions in continental Europe and Japan, which are significantly different from the soil stratas normally encountered in Sweden. To assess the applicability of these methods for Jet Grouting in Swedish soil conditions, the current article provides a description of these methods as well as the Swedish geology in which jet grouting is commonly executed. The resulting predicted diameters from such methods are then examined for three different case studies in the Stockholm region in Eastern Sweden, and the design diameters of the columns are given. The applicability of the current methods is elaborated and the consequences for practical design is discussed. The work concludes that none of the two examined methods can be used by themselves in Swedish soil conditions but need to be supplemented with tests at site.