长江科学院院报 ›› 2024, Vol. 41 ›› Issue (6): 136-142.DOI: 10.11988/ckyyb.20221706

• 岩土工程 • 上一篇    下一篇

干湿循环作用下渠道膨胀土裂隙演化规律及强度特性

杨涛1, 姜海波1, 赵海蛟2   

  1. 1.石河子大学 水利建筑工程学院,新疆 石河子 832003;
    2.伊犁河水利水电投资开发集团有限公司,新疆 伊犁 835000
  • 收稿日期:2022-12-13 修回日期:2023-04-27 出版日期:2024-06-01 发布日期:2024-06-03
  • 通讯作者: 姜海波(1982-),男,湖南长沙人,教授,博士,博士生导师,研究方向为多场耦合作用岩土体多尺度损伤破坏与稳定。E-mail: klaud_123@163.com
  • 作者简介:杨 涛(1998-),男,甘肃武威人,硕士研究生,研究方向为寒旱区水工结构。E-mail: 1979575223@qq.com
  • 基金资助:
    国家自然科学基金项目(51769031);兵团区域创新引导计划项目(2021BB004)

Fracture Evolution and Strength Characteristics of Channel Expansive Soil under Wetting-Drying Cycles

YANG Tao1, JIANG Hai-bo1, ZHAO Hai-jiao2   

  1. 1. College of Water Conservancy & Architectural Engineering, Shihezi University, Shihezi 832003, China;
    2. Yili River Water Resources & Hydropower Investment & Development Group Co.,Ltd.,Yili 835000,China
  • Received:2022-12-13 Revised:2023-04-27 Online:2024-06-01 Published:2024-06-03

摘要: 为探究干湿循环作用下膨胀土渠道边坡裂隙演化特征与强度衰减规律,对北疆某渠道膨胀土开展了不同压实度的干湿循环试验,利用图像处理技术提取膨胀土表面裂隙参数,利用直剪试验测得膨胀土抗剪强度,并分析黏聚力随裂隙率的变化规律。结果表明:在干湿循环作用下,黏聚力的衰减速率随着压实度的增大而增大,内摩擦角总体呈减小趋势,裂隙率的增加速率随着压实度的增加而减小;裂隙相对面积呈先增后减的变化规律。最后,拟合获得不同压实度膨胀土黏聚力与表面裂隙率之间的关系式,通过确定膨胀土表层裂隙率可计算出其黏聚力。研究成果为进一步揭示剧烈干湿变化诱发的膨胀土渠道边坡失稳破坏提供了重要依据。

关键词: 输水渠道, 膨胀土, 干湿循环, 裂隙演化, 抗剪强度

Abstract: To investigate crack evolution characteristics and strength degradation patterns of expansive soil channel slopes subjected to dry-wet cycles, we conducted cyclic dry-wet tests on expansive soil with varied compactness from a channel in northern Xinjiang. Surface crack parameters were extracted using image processing technology, while shear strength was determined via direct shear testing. The relationship between cohesion and crack rate was analyzed. Our findings indicate that, under cyclic drying and wetting, cohesion decay accelerates with higher compaction, while internal friction angle generally decreases. The increase in crack rate slows as compaction rises. The relative crack area initially increases, followed by a decrease. Finally, we established a relationship between cohesion and surface crack rate through fitting. This enables the calculation of expansive soil’s cohesive force based on its surface crack rate. The research findings provide crucial insights into understanding the instability and failure of expansive soil channel slopes under severe dry-wet fluctuations.

Key words: water delivery channel, expansive soil, wetting-drying cycles, fracture evolution, shear strength

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