The Network Simulation Of Jointed Rock Mass Discontinuities

During the long process of geologic evolution, different quantity of tectonic stress fields have had so significant an impact on the rock mass that it shows the characteristics of heterogeneity, randomness, diversity and complexity. As a result, the research of rock mass structure becomes more complex. The property of discontinuities can not be described fully with only several statistics, such as mean, variance and so on. What's more, because of the limit of outcrop and excavation face, the geometric parameters of the inner rock mass discontinuities can not be measured systemically and certainly. The entire description of discontinuity characteristics is very difficult, sometimes even impossible. Thus more advanced analysis methods should be brought into the research of rock mass structure.With the development of computer technology, network simulation of rcck mass discontinuities which is based on statistics and probability theory is improved and brought into discontinuities research. Network geometric graphics are simulated with the the probability distribution of the discontinuities geometric parameters that are measured in-situ. The whole process will be completed by the Monte-Carlo method.In this paper, the method and application in the network simulation of jointed rock mass discontinuities are researched. After the detailed engineering geologic surveying of dam location in Bai Hetan hydroelectric station, dominant discontinuities are identified on the basis of joint isopyenic and joint rose charts with the stereographic projection method. In order to establish the discontinuity statistical model, the geometric parameters of dominant discontinuities including inclination, obliquity, trace and spacing are calculated and analyzed to find out the probability distribution and statistical characteristics of these parameters. Finally, according to the Monte-Carlo method, random variables matching the geometric parameters are programmed to generate and the 2-D network model for rock mass discontinuities is formed.