First we establish explosion criteria for jump processes with an arbitrary locally compact separable metric state space. Then these results are applied to two stochastic coagulation–fragmentation models— the direct simulation model and the mass flow model. In the pure coagulation case, there is almost sure explosion in the mass flow model for arbitrary homogeneous coagulation kernels with expon...

Joints often have important effects on seepage and elastic properties of jointed rock mass and therefore on the rock slope stability. In the present paper, a model for discrete jointed network is established using contact-freemeasurement technique and geometrical statistic method. A coupled mathematical model for characterizing anisotropic permeability tensor and stress tensor was presented and...

Original scientific paper To analyse the influence of joint angle, number and spacing on the strength and acoustic emission (AE) characteristics of rock mass, the uniaxial compression model of rock specimens was established using the micro particle flow PFC2D software platform. The intact rock parameters were determined via trial and error, joints with different angles, numbers and spacing were...

one of the most important parameters used for determining the performance of tunnel boring machines (tbms) is their penetration rate. the parameters affecting the penetration rate can be divided in two categories. the first category is the controllable parameters such as the tbm technical characteristics, and type and geometry of the tunnel, and the second one is the uncontrollable parameters s...

Rock mass classification is analogous to multi-feature pattern recognition problem. The objective is to assign a rock mass to one of the pre-defined classes using a given set of criteria. This process involves a number of subjective uncertainties stemming from: (a) qualitative (linguistic) criteria; (b) sharp class boundaries; (c) fixed rating (or weight) scales; and (d) variable input reliabil...

Rock strata in a coal mining environment are essentially bedded in nature and hence exhibit specific load-deformation characteristics. Mining may induce shearing as well as separation along the bedding planes which may result in bending and subsequent fracturing of the rock layer. This on the other hand may substantially change the in situ fluid flow properties of the rock mass, such as permeab...

The Geological Strength Index (GSI) system, proposed in 1995, is now widely used for the estimation of the rock mass strength and the rock mass deformation parameters. The GSI system concentrates on the description of two factors, rock structure and block surface conditions. The guidelines given by the GSI system are for the estimation of the peak strength parameters of jointed rock masses. The...