Method for representatively sampling subsize rock model structural surface sample sampled based on layering probability

Abstract

A method for representatively sampling a subsize rock model structural surface sample sampled based on layering probability comprises the following steps of: (1) orientationally counting and measuring fluctuation amplitude of a raw rock structural surface sample, respectively calculating a roughness coefficient characteristic constant JRC and a statistic average value of each measuring segment of the scale by a formula; (2) calculating based on quartile division to obtained JRC average values and variances of three intervals: P0-25, P25-75 and P75-100; and (3) setting a relative permissible error of an average value of samples and an ensemble average value to be gamma, and setting confidence to be 95%. The said calculated data is substituted into a layeredly sampling formula to obtain a total sample size, and the sample size of each layer is determined based on the layer weight: W0-25=1 / 4, W25-75=1 / 2 and W75-100=1 / 4. The method provided by the invention can effectively satisfy statistic precision requirement of the shear strength dimension effect of the rock model structural surface, and can raise test statistic precision.

Description

technical field [0001] The invention relates to the field of the size effect of the shear strength of rock mass structural planes, in particular to a representative sampling method for structural plane samples of small-sized rock models. Background technique [0002] The shear strength of the structural plane of rock mass has the characteristic of size effect. In order to obtain the size effect law of the shear strength of the structural plane of rock mass, it is necessary to conduct direct shear tests on the shear strength of structural planes of different sizes. However, due to the characteristics of the direct shear test of structural surfaces, only one destructive test can be carried out on an original rock structural surface. In order to statistically analyze the size effect of structural surface shear strength, model samples of rock structural surfaces of different sizes need to be manually produced. The characteristic of making series size model specimens is that the ...

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Problems solved by technology

[0004] In order to overcome the shortcomings of the existing small-scale rock model discontinuity surface sample sampling method, the inability to meet the statistical accuracy requirements of the shear strength of the rock model discontinuity surface, and the statistical precision of the test are low, the present invention provides a method that can effectively meet the requirements of the rock model discontinuity surface. Statistical accuracy requirements for shear strength and size effects of model discontinuity planes, representative sampling method for small-scale rock model discontinuity plane samples based on stratified probability sampling to improve test statistical accuracy

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