Stability Deterioration Mechanism and Sensitive Parameter Analysis of Dangerous Rock Mass Under Freeze-thaw Cycles

被引：0

作者：

Deng Z. ^{[1
,2
]}

Zhan X. ^{[2
]}

Shu J. ^{[2
]}

Yang S. ^{[1
,2
]}

Cao M. ^{[1
,2
]}

机构：

[1] Jiangxi Province Key Lab. of Environmental Geotechnical Eng. and Hazards Control, Jiangxi Univ. of Sci. and Technol., Ganzhou

[2] School of Civil and Surveying & Maping Eng., Jiangxi Univ. of Sci. and Technol., Ganzhou

来源：

Gongcheng Kexue Yu Jishu/Advanced Engineering Sciences | 2022年 / 54卷 / 02期

关键词：

Dangerous rock mass; Fracture toughness; Freeze-thaw cycle; Frost heaving force;

D O I：

10.15961/j.jsuese.202100086

中图分类号：

学科分类号：

摘要：

The mechanical properties of dangerous rock mass in the cold region are often deteriorated by freeze-thaw cycles due to temperature fluctuation. The establishment of stability analysis method of dangerous rock mass considering fracture toughness deterioration can provide a theoretical basis for long-term stability evaluation of dangerous rock mass engineering in the cold region. The essence of unstable failure of dangerous rock mass is the crack initiation and expansion of the main structural plane. Firstly, according to the theory of fracture mechanics and freezing separation pressure, considering the deterioration of rock of mode Ⅰ fracture toughness caused by freeze-thaw cycle and the frost heaving force of structural plane, the stability evaluation model of dangerous rock mass under freeze-thaw cycle was established. Secondly, based on circular cavity expansion theory, the meso degradation mechanism of ice frost heaving force on micropores in rock was analyzed, and the meso evaluation model of tensile strength under freeze-thaw cycle was established. Thirdly, the evolution equation of mode Ⅰ fracture toughness under freeze-thaw cycles was obtained by theoretical analysis of the relationship between mode Ⅰ fracture toughness and tensile strength, fracture process zone expansion radius. Finally, the deterioration law of the stability of dangerous rock mass under freeze-thaw cycles was analyzed based on an engineering example, and the influence of sensible parameters on the stability coefficient and frost heaving force of dangerous rock mass was discussed. The results showed that the stability of dangerous rock mass in the freeze-thaw environment was related to the tensile strength, elastic modulus, porosity, debris loss ratio and other factors of rock. Under the action of the freeze-thaw cycle, the hole with a smaller radius produced more frost heaving force and had a more significant deterioration effect on the stability of dangerous rock mass. There was a positive correlation between the elastic modulus of rock and the frost heave force, and the smaller the tensile strength of rock, the more likely the frost heave failure as to occur. When the debris loss ratio was greater than 0.8, the effect of the freeze-thaw cycle on the long-term deterioration of dangerous rock mass was stronger. Therefore, it is important to control the debris loss caused by frost heave failure for the long-term stability of dangerous rock mass in the cold region. Copyright ©2022 Advanced Engineering Sciences. All rights reserved.

引用

页码：150 / 161

页数：11

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