SYNOPSIS Thin spray-on liners (TSLs) have been used as sealants and rock support in tunnels for over 25 years. Laboratory tests indicated satisfactory properties that can provide adequate strength, adhesion, toughness, elasticity part of systems mining excavations. These characteristics are, however, not always demonstrated practice, when mine environmental conditions do correspond with laborat...

Based on aluminum sulfate, a fluorine-free and alkali-free liquid accelerator (FF-AF-A) was prepared in this study. The setting time compressive strength of three cement types with different FF-AF-A dosages were fully investigated. compatibility the superplasticizers also investigated, early hydration behavior morphology products reference paste explored by heat, X-ray diffractometry (XRD), sca...

TSL materials for ground support were initially intended to be used as an alternative to mesh or shotcrete. The first trials on TSL technology were initiated in Canada in the late 1980s (Archibald et al., 1992). Early research led to the development of a polyurethane based product. In the 1990s, numerous advantages in terms of speed of application and minimizing transportation of materials were...

Driven by progress in sensor technology, computer software and data processing capabilities, terrestrial laser scanning has recently proved a revolutionary technique for high accuracy, 3D mapping and documentation of physical scenarios and man-made structures. Particularly, this is of great importance in the underground space and tunnel construction environment as surveying engineering operatio...