A Method for Determining the Characteristic Unit Volume of Fractured Rock Mass

Abstract

The invention relates to a method for determining representative elementary volume (REV) of jointed rock mass. The method comprises the following steps of: selecting actual jointed rock mass of any size, and drawing a 3D (three-dimensional) digital model of the actual jointed rock mass; rotating the 3D digital model so as to ensure that the three-dimensional digital model forms different inclination angles relative to the horizontal direction, and performing 3D printing so as to prepare similar materials with inclination angles different from those of the actual jointed rock mass; measuring penetration rates Ka of the similar materials with different inclination angles (1 / square root of Ka), establishing a coordinate axis, and drawing a closed curve by utilizing values of different inclination angle directions as distances between points to an original points; quantitatively analyzing whether permeability coefficients in different directions of the jointed rock mass conform to the permeability tensor rule according to the similarity between the closed curve and an oval; enlarging or reducing the volume of the selected actual jointed rock mass according to quantitative analysis result, repeating the above steps, and determining the REV of the actual jointed rock mass. The method is capable of fully simulating the actual jointed rock mass; the obtained REV value has slight difference from that of the actual jointed rock mass; compared with a numerical method, the method is capable of achieving relatively accurate REV of the rock mass.

Description

technical field [0001] The invention relates to a method for determining the volume of a fractured rock mass representation unit, in particular to a method for determining the volume of a fractured rock mass representation unit through an indoor model test based on 3D printing technology, which is suitable for determining the REV of different types of complex fractured rock mass , belonging to the technical field of geotechnical engineering. Background technique [0002] Natural rock mass generally has structural planes such as fissures, joints, skirt folds, and faults, which make the mechanical properties of the rock mass very complex. Since the structure of the rock mass plays a decisive role in the mechanical properties of the rock mass, there are Size effect, that is, as the volume of rock mass changes, the mechanical parameters of rock mass (strength, elastic model, friction angle, cohesion and permeability coefficient, etc.) will change accordingly, but when the volume...

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Problems solved by technology

[0009] However, compared with the method of determining the REV of fractured rock mass through experiments, it is inevitable to use many simplified assumptions to determine the REV of fractured rock mass by analytical methods and numerical simulation methods, and the obtained rock mass model is quite different from the actual fractured rock mass. , the characteristics of the actual fractured rock mass cannot be fully considered, and the calculated REV of the fractured rock mass is quite different from the REV of the actual fractured rock mass. Therefore, a more effective method for determining the REV of the fractured rock mass is urgently needed

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