ISSN 1003-8035 CN 11-2852/P
    张曦,骆建文,潘俊义,等. 陕西榆林毛乌素沙漠南缘风积沙的湿陷规律及其影响因素[J]. 中国地质灾害与防治学报,2024,35(4): 75-84. DOI: 10.16031/j.cnki.issn.1003-8035.202307023
    引用本文: 张曦,骆建文,潘俊义,等. 陕西榆林毛乌素沙漠南缘风积沙的湿陷规律及其影响因素[J]. 中国地质灾害与防治学报,2024,35(4): 75-84. DOI: 10.16031/j.cnki.issn.1003-8035.202307023
    ZHANG Xi,LUO Jianwen,PAN Junyi,et al. Collapse characteristics and influencing factors of wind-blown sands in the southern margin of Mu Us Desert, Yulin, Shaanxi Province[J]. The Chinese Journal of Geological Hazard and Control,2024,35(4): 75-84. DOI: 10.16031/j.cnki.issn.1003-8035.202307023
    Citation: ZHANG Xi,LUO Jianwen,PAN Junyi,et al. Collapse characteristics and influencing factors of wind-blown sands in the southern margin of Mu Us Desert, Yulin, Shaanxi Province[J]. The Chinese Journal of Geological Hazard and Control,2024,35(4): 75-84. DOI: 10.16031/j.cnki.issn.1003-8035.202307023

    陕西榆林毛乌素沙漠南缘风积沙的湿陷规律及其影响因素

    Collapse characteristics and influencing factors of wind-blown sands in the southern margin of Mu Us Desert, Yulin, Shaanxi Province

    • 摘要: 随着中国干旱、半干旱地区的开发与发展,湿陷性沙土对工程建设的危害日益显著。为探明沙土的湿陷规律及其影响因素,文章以毛乌素沙漠南缘风积沙土为研究对象,首先,通过控制单因素室内压缩试验,研究不同工况下风积沙的湿陷规律;其次,采用 PFC3D(三维颗粒流软件)对风积沙土室内压缩试验进行数值模拟,探究不同孔隙率、不同颗粒组成对沙土湿陷性的影响。研究结果表明:沙土湿陷系数随压力呈先升后降的变化趋势,压力为 150 kPa 时取得湿陷系数最大值;随着干密度或含水率的增大,沙土湿陷系数减小。相较于含水率,干密度对沙土湿陷性的影响更大;风积沙土的湿陷系数与孔隙率之间呈正相关关系,毛乌素沙漠南缘风积沙土的湿陷起始孔隙率为 0.425;当 0.075~0.25 mm、0.25~0.5 mm两粒组颗粒含量之比为 0.35∶0.65 时,沙土湿陷性最大。研究结果较全面地描述了沙土室内压缩试验从宏观到微观的全过程,从多尺度揭示了沙土湿陷性的湿陷规律及其影响因素,可为毛乌素沙漠地区工程建设提供参考,同时为沙土在颗粒流数值模拟方面的研究提供了一定的思路和依据。

       

      Abstract: With the development of arid and semi-arid regions in China, the hazards posed by collapsible sands to engineering construction have become increasingly significant. In order to investigate the collapsibility regularity and its influencing factors of sand soils, this paper focuses on the wind-blown sands at the southern edge of the Maowusu Desert. Initially, by controlling the single factor laboratory compression tests, the collapsibility regularity of wind-blown sand under different working conditions was investigated. Subsequently, using PFC3D (three-dimensional particle flow software) for numerical simulation of the laboratory compression tests on wind-blown sands, the paper explores the effects of different porosities and particle compositions on the collapsibility of sandy soils. The research results indicate that the collapsibility coefficient of sandy soils shows a trend of first increasing and then decreasing with pressure, reaching its maximum value at 150 kPa. With the increase in dry density or moisture content, the collapsibility coefficient of sand decreases. Compared to moisture content, dry density has a greater impact on the collapsibility of sandy soils. There is a positive correlation between the collapsibility coefficient of wind-blown sand and its porosity. The initial porosity of the collapsibility of the wind-blown sand on the southern edge of the Maowusu Desert is 0.425. When the ratio of particle content between 0.075~0.25 mm and 0.25~0.5 mm is 0.35∶0.65, the collapsibility of sandy soils is maximized. The research results comprehensively describe the entire process of laboratory compression tests on sand from macro to micro levels, revealing the collapsibility regularity and its influencing factors on wind-blown sand from multiple scales. This can provide a reference for engineering construction in the Maowusu Desert and provide certain ideas and basis for the research on particle flow numerical simulation of sand.

       

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