A method to determine the degree of freeze-thaw damage of rocks in high-altitude cold regions

Abstract

The invention discloses a method for determining freezing-thawing damage degree of a rock in a high-altitude cold region. The method comprises the following steps: selecting a high-altitude cold region rock sample, drying the sample to a constant weight, cooling the sample, and saturating the sample with water; performing freeze-thaw cycle treatment on the water-saturated sample, measuring the gaspermeability of the sample under the same confining pressure under the same osmotic pressure after different freeze-thaw cycles, drawing a change curve of the gas permeability of the rock with different freeze-thaw cycles, and fitting the curve; defining a calculation formula of a freezing-thawing damage quantity D: D = 1 - (ki / k0),wherein k0 is the gas permeability of the sample before freezingand thawing, ki is the gas permeability of the sample after i freezing-thawing cycles, and i=1, 2, 3, 4...; and drawing a change curve of the freezing-thawing damage quantity of the rock with the number of freezing-thawing cycles, fitting the curve by a function, and determining the according to the degree of rock damages caused by any freezing-thawing cycle according to the fitting function. Themethod defines the freezing-thawing damage quantity of the rock by the gas permeability of the rock, and makes a test result accurate, scientific and reliable.

Description

technical field [0001] The invention relates to a method for determining the degree of rock damage, in particular to a method for determining the degree of freeze-thaw damage of rock in high-altitude cold regions, and belongs to the field of rock engineering. Background technique [0002] The degree of rock damage under freeze-thaw weathering is one of the most important factors to consider for the long-term safety of rock engineering in high-altitude cold regions of the Qinghai-Tibet Plateau. problems facing sex. [0003] At present, many scholars mainly use the mechanical parameters (such as strength and elastic modulus) of the rock after freezing and thawing to define the freeze-thaw damage amount of the rock. However, as an anisotropic material, the mechanical properties of the rock are relatively discrete; The freeze-thaw damage of rock is defined by the compressional wave velocity of the rock, but the compressional wave velocity is less sensitive to the number of free...

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Problems solved by technology

[0003] At present, many scholars mainly use the mechanical parameters (such as strength and elastic modulus) of the rock after freezing and thawing to define the freeze-thaw damage amount of the rock. However, as an anisotropic material, the mechanical properties of the rock are relatively discrete; The longitudinal wave velocity of the rock is used to define the amount of freeze-thaw damage to the rock, but the longitudinal wave velocity is less sensitive to the number of freeze-thaws

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