ABSTRACT
Over the past several years LKAB’s Kiirunavaara underground iron ore mine in Sweden has been pursuing a study on the interaction of its surface rock support system and the rock mass. One of the major areas of this study is the interaction between shotcrete and rock. The actual interaction between the shotcrete and rock is quite complex as shown by for example, Holmgren (1979, 1985), Stille (1992), Stacey (2001) and Malmgren (2001). Although complex the interaction itself is after all dependent on the strength of the
interface and its governing mechanical properties, particularly the stiffness and friction coefficients. At a genuinely cemented interface the adhesion strength is important. External factors such as rock surface preparation and geometry of the rock surface on which shotcrete is applied have been found to affect the adhesion strength quite significantly. Malmgren (2001) has shown that the adhesion strength of the shotcreterock interface at Kiirunavaara underground iron ore mine was significantly increased when the rock surface was prepared by water-jet scaling.
