A numerical technique for assessing joint rock coefficients

A numerical technique for assessing joint rock coefficients

en

Joints in rocky massifs usually form a space network that is hidden under the surface of terrains. Although normally invisible, same parts of such networks may emerge when excavation work is running in terrains. The irregularity of joint rock surfaces are characterized by joint rock coefficients that serve for computations of shear strength of these joints. This is important for evaluation of the mechanical stability not only the rock joints themselves but also for the mechanical stability of rock massifs that are usually composed of the network of rock joints. The sear strength of rock joints is therefore critical for stability of the whole massif. The joint rock coefficients can be determined, among others, by the computerized procedure based on numerical indicators assessing the morphology of jointed surfaces. For the reliable assessing of rock joints, the numerical indicators should fulfill some properties that are subject of discussion presented in this contribution. The comparative principle used in geotechnics is explained in detail. This principle requires that the surface profiles may be compared on the basis of their dynamical compatibility. Their geometrical shape are therefore only auxiliary property but not the only decisive property. This fact is often omitted and, as a consequence, an incorrect assessment can be performed. All these points are discussed and explained.

Joints in rocky massifs usually form a space network that is hidden under the surface of terrains. Although normally invisible, same parts of such networks may emerge when excavation work is running in terrains. The irregularity of joint rock surfaces are characterized by joint rock coefficients that serve for computations of shear strength of these joints. This is important for evaluation of the mechanical stability not only the rock joints themselves but also for the mechanical stability of rock massifs that are usually composed of the network of rock joints. The sear strength of rock joints is therefore critical for stability of the whole massif. The joint rock coefficients can be determined, among others, by the computerized procedure based on numerical indicators assessing the morphology of jointed surfaces. For the reliable assessing of rock joints, the numerical indicators should fulfill some properties that are subject of discussion presented in this contribution. The comparative principle used in geotechnics is explained in detail. This principle requires that the surface profiles may be compared on the basis of their dynamical compatibility. Their geometrical shape are therefore only auxiliary property but not the only decisive property. This fact is often omitted and, as a consequence, an incorrect assessment can be performed. All these points are discussed and explained.