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| Damage characteristics of freezing-thawing rock with lognormal distribution of microelement strength are considered |
| Received:September 16, 2021 Revised:December 05, 2021 |
| View Full Text View/Add Comment Download reader |
| DOI：10.7511/jslx20210916001 |
| KeyWord:freeze thaw cycle confining pressure quasi brittle rock lognormal distribution damage characteristics |
| Author | Institution |
| 罗勇 |
西安科技大学 建筑与土木工程学院, 西安 |
| 杨更社 |
西安科技大学 建筑与土木工程学院, 西安 |
| 刘慧 |
西安科技大学 建筑与土木工程学院, 西安 |
| 郁金捷 |
西安科技大学 建筑与土木工程学院, 西安 |
| 刘杰 |
西安科技大学 理学院, 西安 |
| 蔺江昊 |
西安科技大学 建筑与土木工程学院, 西安 |
| 贠烨辉 |
西安科技大学 建筑与土木工程学院, 西安 |
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| Abstract: |
| The mechanical properties of quasi-brittle rocks damage in freeze-thaw environments have important implications for engineering construction in cold regions.Due to the presence of characteristic lengths in quasi-brittle rocks, its scale effects no longer conform to the statistical theory of Weibull scale effects.The article takes quasi-brittle rocks as the research object, based on the micro-unit strength of quasi-brittle rocks obeying a log-normal distribution, based on the D-P damage criterion, the damage mechanics theory is used to establish the intrinsic damage model of freeze-thaw quasi-brittle rocks under the action of surrounding pressure, and the damage characteristics of freeze-thaw quasi-brittle rocks are discussed.This research shows:(1) The constitutive damage model of quasi brittle rocks based on lognormal distribution is consistent with the experimental results.The model reflects the interaction of total damage of quasi brittle rocks along strain, confining pressure and freeze-thaw cycle path under a freeze-thaw environment, and can reveal the essential characteristics of damage evolution of quasi brittle rocks. (2) The stress-strain relationship of quasi brittle rocks under freeze-thaw and confining pressure can be divided into linear elastic stage, nonlinear strengthening stage, stress weakening stage and strain decline stage. (3) When the confining pressure of quasi brittle rocks is constant, the number of freezing and thawing is the key factor to increase the total damage of quasi brittle rocks.The number of cycles of freeze-thaw is a factor for promoting the damage degradation of brittle rocks.When the number of cycles of freeze-thaw is constant, the total damage of frozen thaw load decreases with the increase of confining pressure, that is, the deterioration of mechanical properties of the quasi brittle rocks under confining pressure plays a role in inhibiting the deterioration of mechanical properties.The research of this paper has a certain role in promoting the theoretical analysis of the safety and stability of rock mass engineering in cold regions. |
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