Permeability tensor test method and anisotropy quantification assessment method for columnar jointed rock

Abstract

The invention relates to a permeability tensor test method and anisotropy quantification assessment method for columnar jointed rock. The permeability tensor test method includes: simulating actual columnar jointed rock to be measured to prepare similar materials with different cylinder inclination angles; measuring the permeability of similar materials; and according to the measured the permeability of similar materials, presenting the method for calculation of columnar jointed rock permeability tensor and permeability anisotropy quantification assessment. Based on the principle of tensor invariance, the method measures the permeability of similar materials with different cylinder inclination angles to obtain permeability tensor, permeability principal direction and osmotic principal value of the columnar jointed rock; and according to different types of actual columnar jointed rocks, corresponding similar materials can be prepred. The method solves the problem of indoor test for the measurement of natural rock permeability tensor and the problem of discreteness of testing results caused by the difference of natural rock, and has the advantages of low measurement cost, strong operability, accurate results and wide scope of application.

Description

technical field [0001] The invention relates to a method for testing the permeability tensor of columnar jointed rock mass and an anisotropy quantitative evaluation method, in particular to a method for determining the permeability tensor of columnar jointed rock mass and the principal permeability coefficient and principal permeability tensor of the permeability tensor based on the principle of tensor invariance. Orientation method and method for quantitative assessment of permeation anisotropy. Background technique [0002] Columnar joints are irregular or regular primary tensile fracture structures formed due to cooling and contraction during the eruption and overflow of volcanic lava. Columnar joints mostly appear in basalt and are widely distributed in Southwest China. Many of them have been built or are under construction in Southwest my country. Large-scale hydropower stations are located on columnar jointed basalt. As a special structural rock mass, columnar jointed r...

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Problems solved by technology

[0002] Columnar joints are irregular or regular primary tensile fracture structures formed due to cooling and contraction during the eruption and overflow of volcanic lava. Columnar joints mostly appear in basalt and are widely distributed in Southwest China. Many of them have been built or are under construction in Southwest my country. Large-scale hydropower stations are located on columnar jointed basalt. As a special structural rock mass, columnar jointed rock mass has anisotropy in mechanical properties and permeability. Since columnar jointed rock mass contains multiple groups of joints and The volume of the column is large, and the natural rock samples taken according to the size of the laboratory test contain only one group or no joints, which cannot reflect the seepage anisotropy of the jointed rock mass, and the geometric properties of the columnar jointed rock mass are variable. There are large differences in body joints, the test results of natural rock samples taken from some rock masses are not fully representative, and there is no effective method for measuring the permeability tensor, the main value and the main direction of the permeability tensor of columnar joint rock mass, so although The seepage properties of columnar jointed rock mass have a significant impact on the mechanical properties of rock mass and engineering safety, but there are few studies on the seepage properties of columnar jointed rock mass

[0003] Zou Lifang et al studied the permeability of columnar joint rock mass by using the block combination to conduct physical model experiments, but did not consider the anisotropy of columnar joint rock mass permeability, and there are few studies on the characterization methods of rock mass permeability anisotropy. Some people express the permeability anisotropy by the ratio of the maximum value and the minimum value of the permeability of the rock mass, but this method can only reflect the ratio of the maximum value and the minimum value, and cannot fully reflect the anisotropy of the permeability

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