The Theory And Developing Of The Program Of 3-D Network Modeling For Random Discontinuities

Rock mass, with certain ingredients and unique structure, has gone through many times and repeated geological processes. There are many discontinuities with different causes and characteristics in rock mass, and they cut the rock into rock blocks of different shape, size and various compositions, making the rock mass discontinuity and not uniformity, which plays a key role in mechanical properties rock stability.The research object of three-dimensional (3-D) network simulation is geometrical shape of discontinuity, so it is simplified to a disk. According to the field measured data of orientation, spacing and trace length, the geometric characteristic parameter and the probability distribution are obtained, basing on the methods of statistics, probability and analytic geometry. Using the method of Monte-Carlo simulation, a 3-D network model is built,which gives a visual image of discontinuities being in a three dimensional space.Basing on the previous research, this paper summarizes the basic principles of three-dimensional network simulation of discontinuities and the probability distribution of orientation, spacing, trace length, et al., according to the relationship between trace length and diameter, estimates the size and probability distribution discontinuity; in accordance with the characteristics of a transversely isotropic, the concept of layer density is introduced, as well as the formula for estimating it, and the position of discontinuities is calculated using a layer-by-layer modeling method. Based on probability, stochastic and Monte Carlo simulation, a program system called three-dimensional discontinuity network simulation program (TDNSP) is developed in object-oriented Microsoft Visual C++ ? (release 6.0). The program contains four parts to implement the 3-D network simulation model: generating random numbers, fitting and testing functions, building 3-D network simulation model and visualization, verifying the model to realize the three-dimensional discontinuity network simulation with the assumption of transversely isotropic. In order to test whether the discontinuity network model accords with the relative statistics, three kinds of validation methods are proposed, namely, the virtual scan line, virtual section and virtual layer.In order to validate the effectiveness of the system TDNSP that is described above, a slope near a highway (the Chenjiazhuang highway slope) is taken as an example, which is a part of a proposed enlarged road that is located in the Mentougou District of Beijing, China.