| 蔡正银,朱锐,黄英豪,张晨,郭万里,陈皓.冻融过程对膨胀土渠道边坡劣化模式的影响[J].水利学报,2020,51(8):915-923 |
| 冻融过程对膨胀土渠道边坡劣化模式的影响 |
| Influences of freeze-thaw process on the deterioration mode of expansive soil canal slope |
| 投稿时间：2020-02-12 |
| DOI：10.13243/j.cnki.slxb.20200064 |
| 中文关键词: 湿干冻融 湿干循环 膨胀土 渠道边坡 裂隙 离心模型试验 |
| 英文关键词: wet-dry and freeze-thaw wet-dry cycles expansive soil canal slope crack centrifugal model tests |
| 基金项目:国家重点研发计划项目（2017YFC0405100）；国家自然科学基金项目（51709185，51879166，51909170）；中央级公益性科研院所基金基本科研业务费项目（Y319010）；中国博士后科学基金（2018M640500） |
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| 中文摘要: |
| 干湿作用和冻融作用是季冻土地区复杂环境的两种基本形式，深刻影响着输水渠道的长期稳定性。以北疆膨胀土渠道边坡为研究对象，开展了湿干循环及湿干冻融耦合循环作用下膨胀土渠道边坡劣化过程离心模型试验，探讨了湿干冻融耦合循环作用中的冻融过程对膨胀土渠道边坡劣化模式的影响。试验结果表明：湿干循环作用下膨胀土渠道边坡的劣化模式主要为浅层土体强度衰减和表面裂隙发育，同时伴随着显著的土体崩解剥落特征；湿干冻融耦合循环作用下膨胀土渠道边坡劣化过程中则未出现明显的土体崩解剥落现象，主要劣化模式为渠顶区域土体裂隙拓展、连通；湿干冻融耦合循环作用中的冻融过程使得渠顶处的渠水入渗量大幅增长，造成渠顶土体的干湿循环幅度增大，诱使膨胀土渠道边坡的劣化过程由浅层土体往深层土体发展，在宏观上表现为渠顶及渠坡水位线以上区域内裂隙的连通程度增高、拓展宽度及深度增大，并最终发展为贯穿渠顶的横向张拉裂隙。膨胀土渠道边坡在湿干冻融耦合循环作用下有着自贯穿渠顶的横向裂隙发生失稳破坏的趋势。 |
| 英文摘要: |
| The actions of wet-dry and actions of freeze-thaw are two basic forms of the complex environment in the seasonally frozen soil regions, which affect the long-term stability of the water delivery canal significantly. Taking the expansive soil canal slope in North Xinjiang as the research object, centrifugal model tests on deterioration process of expansive soil canal slope under the action of wet-dry and coupling wet-dry and freeze-thaw were conducted to study the effect of freeze-thaw process on deterioration mode of expansive soil canal slope. The experimental results show that the deterioration mode of the expansive soil canal slope under the cyclic action of wet-dry is mainly the strength attenuation of shallow soil and the development of surface crack, accompanied by the significant characteristics of soil disintegration; During the deterioration process of the expansive soil canal under the cyclic action of coupled wet-dry and freeze-thaw, there is no obvious phenomenon of soil disintegration. The main deterioration mode is the development and connection of cracks on the canal top; The freeze-thaw process in the coupled wet-dry and freeze-thaw cycles makes the canal water infiltration at the canal top increase significantly, resulting in an increase in the wet-dry range of the soil at the canal top,which induces the deterioration of the expansive soil canal slope from shallow soil develops towards deep soil. The connectivity, width and depth of the cracks on the canal top increase, and eventually it develops into a lateral tensile crack through the canal top. The expansive soil canal slope has a tendency of instability due to lateral cracks running through the canal top under the cyclic action of coupled wet-dry and freeze-thaw. |
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