Research On Parameter Interpretation Of Rock Discontinuities And Network Model Based On Digital Image

The mechanical strength of structural plane is a relatively weak position in rock mass. Structural plane plays an important role in controlling the deformation, failure mode and hydraulic properties of rock mass, the study of discontinuities is a significant part in rock mechanics. With the development of digital information technology, the survey of rock structural plane is changing from the traditional cumbersome and inefficient way of contact measurement into the high-precision and high efficiency way of 3D laser scanning and close range photogrammetry. On this basis, the establishing of the three dimensional network model can lay a good foundation for the study of stability, permeability and other engineering properties of rock. Besides, it has a strong practical significance for the construction.This paper takes the granite structural plane of Gansu Beishan as the research object. It generates the point cloud model to get parameter information of rock structural plane on the base of multi-baseline close range photogrammetry. Meanwhile, in order to obtain a more precise three dimensional network model of structural plane, this paper proposes a method that is combined with rock partition and DE algorithm to optimize the bulk density in the reference of the areal density. Using this method to establish the three dimensional network model has good prospects for development. The research achievements are summarized as follows:(1) Using the method of match and intersection based on multi-baseline digital close range photogrammetry to solve the three dimensional coordinates of the feature points. Then, compared with values obtained by single baseline method, this method has higher interpretation accuracy.(2) Through the method of point cloud model stitching, the larger range outcrop can be reconstructed which effectively reduce the complete form of the outcrop surface. Importing crack path on the reconstruction model, at the same time, the arrangement of continuous circular and rectangular simulation test window can be able to calculate the surface density and mean trace length of structural plane.(3) On common PC platform, the newly developed software using DE algorithm is able to solve occurrence of the structural plane which is in a linear distribution. Then compared with the actual statistical value, the result has higher precision and satisfies the need of practical engineering.(4) Using differential evolution algorithm develop the calculation software for the bulk density optimization. On the basis of areal density and bulk density, the fracture parameters in space position can be achieved. This data can be used to establish three dimensional network model with a higher degree of certainty.