The Spatial Distribution Characteristics Of Structural Planes In The Granite Rock Mass Of Beishan Area Based On GIS

The diagnoses and modeling of structural plane in granitic mass is an important aspect in the research of granite engineering rock mass. In fact, the spatial distribution of structural plane in the rock mass has variability, and the variation may be uniform or non-uniform, random or regular. The variation can be expressed in the same or difference between the structural plane distribution characteristics, geomechanics and hydrogeological characteristics from one engineering geological unit to another. Thus, grasping the spatial distribution of structural plane is not only the foundation of studying stability and permeability, but also practical on engineering construction.This paper focuses on the spatial distribution characteristics of granite structural plane in Gansu Beishan area. The preliminary structural plane data and the spatial distribution of structural plane were obtained and applied in the rock quality evaluation and the modeling of three-dimensional structural plane.The research achievements are summarized as follows:1. Firstly, the approach of obtaining the structural plane data was innovated and the GPS-RTK technique was used to measure the trace length of structural plane. This method greatly improves the access rate of structural plane data. Afterwards, the structural plane data is stored on the GIS platform, which provides a convenient basis for the data management and the subsequent analysis and processing of data. 2. The toolbox of GIS was used to analyse the spatial distribution of structural plane in the representative region, especially the fractal characteristics and geostatistical characteristics were analysed:①There is fractal characteristic in the spatial distribution of structural plane in granitic mass of Beishan, and the fractal characteristic has a strong correlation with structural plane density value, which provides and important reference for the whole evaluation of the spatial distribution and the evaluation of rock mass quality;②By the method of geostatistical analysis, it is found that there is obvious anisotropy in the spatial distribution of structural plane in the research area, especially the characteristic of anisotropic axis is very obvious;3. By the analysis of variation features and grouping of the anisotropic axis, it turns out that the degree of variability about different groups isn’t same. Group1has the similar spatial distribution with the whole research area, i.e."hole-effect" characteristic;4. The "hole-effect" characteristic should be paid special attention in the modeling of plane network. The modeling is carried out on the basis of considering the periodical distribution of group1structural plane. The two-dimensional simulation of group1is realized in the MATLAB programming environment. Suggests and skills are also proposed for three-dimensional modeling of structural plane network.