Publication Abstract

Proceedings of the Deep Mixing 2015 Conference, (DFI)

Deep Stabilisation in Sulphide Soil for Embankments in Sweden - Laboratory and Field Studies
Mattias Andersson, Swedish Geotechnical Institute, Sweden; Yvonne Rogbeck, Swedish Geotehnical Institute, Sweden; Bo Westerberg, Swedish Geotehnical Institute, Sweden

Deep stabilisation has been used in Sweden for decades. The method has been improved to allow it to be used in different types of soils and with new binders. One challenging soil type in Sweden is so-called sulphide soil, a fine-grained soil which contains organic material and iron sulphides. There have been some cases in Sweden of problems when using deep stabilisation in this type of soil, and in one case a slope failure occurred. This paper shows that it is possible to achieve good results with deep stabilisation in sulphide soils. Laboratory and field studies from a test site along the Botniabanan railway line in Sweden are presented. Geotechnical and chemical properties of the natural soil were investigated in the laboratory and one or more of these properties may explain the differences in the stabilising effect of sulphide soils. The strength of the laboratory samples and the columns in the field were tested and compared. It is shown that a satisfactory stabilisation effect can be achieved with the proper choice of binder, amount of binder added, curing time and mixing energy. In sulphide soils, more binder additive is needed than in "ordinary" inorganic clays.

 article #2118; publication #1013 (DM-2015)