| 引用本文: | 王理想,袁晓铭,苏安双,李兆宇.非饱和分散性黏土多次冻融特性试验[J].哈尔滨工业大学学报,2021,53(5):141.DOI:10.11918/201909158 |
| WANG Lixiang,YUAN Xiaoming,SU Anshuang,LI Zhaoyu.Experimental study on properties of unsaturated dispersive clay after multiple freezing-thawing cycles[J].Journal of Harbin Institute of Technology,2021,53(5):141.DOI:10.11918/201909158 |
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| 摘要: |
| 针对中国季节性冻土区分散性黏土,通过室内非饱和冻融试验,探索其在不同初始含水率、干密度、多次冻融下的冻胀融沉特性.结果表明:分散性黏土的冻融特性明显区别于一般性非分散性黏土,其冻胀量远大于非分散土；多次冻融后,分散性黏土冻胀表现为冻胀后松散特性,而非分散土冻胀表现为冻融密实特性；初始含水率、干密度和冻融次数对融沉系数和冻胀率影响较大；初始含水率越大,冻胀量和融沉量越大；多次冻融后,分散性黏土内部含水率重新分布,初始含水率越低,相应部位含水率增大百分率越大；在有外界补水下,初始含水率较高的分散性黏土经过2次以上冻融后均可表现为强冻胀；不同干密度的分散性黏土,融沉系数随冻融次数增大而增大,后趋于稳定.试验得到的新认识可为“一带一路”北线黑龙江和吉林两省公路、铁路和水利工程建设提供指导,以采用必要措施减小分散性黏土冻融破坏. |
| 关键词: 非饱和分散土 多次冻融 季节性冻土区 冻胀率 融沉系数 |
| DOI：10.11918/201909158 |
| 分类号:U441 |
| 文献标识码:A |
| 基金项目:中央级公益性研究所基本科研业务费专项重点项目(2018A01);国家自然科学基金(51378164);黑龙江省自然科学基金(ZD2019009) |
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| Experimental study on properties of unsaturated dispersive clay after multiple freezing-thawing cycles |
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WANG Lixiang1,2,YUAN Xiaoming1,SU Anshuang2,LI Zhaoyu2
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(1.Key Laboratory of Earthquake Engineering and Engineering Vibration of China Earthquake Administration (Institute of Engineering Mechanics, China Earthquake Administration), Harbin 100080, China; 2.Heilongjiang Province Hydraulic Research Institute, Harbin 100086, China)
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| Abstract: |
| The frost heaving and thawing characteristics of dispersive clay in seasonal frozen soil region of China were studied by freezing-thawing test with different initial moisture contents, dry densities, and multiple freezing-thawing cycles. Results show that the freezing-thawing characteristics of dispersive clay were significantly different from those of non-dispersive clay, and the frost heaving amount of dispersive clay was much larger than that of non-dispersive clay. After several cycles of freezing-thawing, the dispersive clay exhibited loose property after frost heaving, while the non-dispersive clay showed compaction property. The initial moisture content, dry density, and freezing-thawing times had great influence on the thawing settlement coefficient and frost heave rate. The larger the initial moisture content was, the larger the frost heaving amount and the thawing settlement were. After multiple freezing-thawing cycles, the internal moisture content of the dispersive clay was re-distributed, and the lower the initial moisture content was, the higher the percentage increase of moisture content was in the corresponding part. In the case of external water replenishment, the dispersive clay with higher initial moisture content exhibited strong frost heaving after more than two times of freezing-thawing. For dispersive clay with different dry densities, the thawing settlement coefficient increased with increasing numbers of freezing-thawing cycles, and then tended to be stable. The experiment results will provide guidance for the necessary measures to reduce freezing-thawing damages of dispersive clay in the construction of highways, railways, and water conservancy projects in the northern line of “Belt and Road” in Heilongjiang and Jilin provinces. |
| Key words: unsaturated dispersive clay freeze-thaw cycles seasonal frozen soil region frost heave rate thawing settlement coefficient |
