Method for determining freezing-thawing damage degree of rock in high-altitude cold region

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...

AI Technical Summary

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

Images