20 Years of European case histories about continuous soilmix walls

Abstract

Amongst all existing ground improvement techniques, deep cement mixing knew a big leap forward with the emergence of new technologies in the early 21st century. One of those, called Trenchmix® technique, involves a trencher to form continuous soil-cement walls by mixing the disaggregated ground with a binder on full depth in a single pass. As shown in this paper, the binder may be introduced either as a powder or in the form of a cementitious grout. The soil mixed material then self-hardens forming a barrier with a greatly reduced permeability and enhanced strength.This paper reviews 20 years of case histories with single pass trenching technology in Europe, through a wide range of applications dealing with ground improvement, slope stability, cut-off walls, retaining walls and environmental remediation. A particular highlight is provided on the properties of the soilmix walls constructed with this technology, with a focus on laboratory results vs field results about unconfined compressive strength and hydraulic permeability.