ABSTRACT
Responsible for clogging are mainly adhesion processes that occur at the interfaces and at the surfaces of the clay minerals and tools (Spagnoli et al. 2010a). For instance, according to Thewes (1999), Feng (2004) and Weh et al. (2009), clays which leads to clogging problems are high cohesive with high liquid limits and a high plasticity index. Hence, these types of soils tend to become very sticky on contact with water, due to the swelling effect of clay particles. Several solutions are present on the market but not always their performances are satisfactory. Besides, not always the chemomechanical properties of clays are well understood. The clogging problem, therefore, remains an important issue during the tunnel constructions. Clogging can constrain mechanical tunnelling through to a complete standstill.
