摘要
开展黄土微观结构研究有助于揭示宏细观黄土体渗流、黄土滑坡滑动面形成机制和过程。构建了含裂隙和不含裂隙两类黄土微观结构连通模型,探讨了孔隙连通率p、孔隙变异系数λ、裂隙最大跨度ω及裂隙网络贯通率q等参数之间的关系,并通过黄土微观结构扫描式电子显微镜试验和野外渗流试验对两类模型的连通阈值进行了验证。结果表明:裂隙的存在,特别是其跨度大小,对黄土孔隙形态大小及其分布特征具有重要影响;裂隙是优先流的重要通道,是较低孔隙率条件下发生黄土优先流的重要原因;黄土微观结构优先连通模型研究结论与黄土渗流试验结论基本吻合,揭示了泾阳南塬“漫灌式”灌溉行为对含裂缝的高陡边坡稳定性的不利影响以及东风村、蒋刘村等大型滑坡发生的根本原因。
Investigation of loess microstructure can reveal information on the seepage of loess masses and the formation and evolution of sliding surfaces in loess landslides at both macroscopic and mesoscopic levels.A loess microstructure connectivity model,both with and without fractures,is established to investigate the relationships among pore connectivity p,pore variation coefficientλ,maximum fracture spanω,and fracture network penetration q.The connectivity thresholds of these two models are verified through scanning electron microscopy analysis and field seepage tests of loess microstructure.The results show that the existence of fractures,especially their time spans,substantially affects the morphology,size,and distribution of pores in loess.Fractures are important channels for preferential flow and significant contributors to loess preferential seepage under low porosities.The research conclusions from the loess microstructure preferential connectivity model studies agree with the loess seepage test results.These results explain the negative effects of the“flooding-type”irrigation in Nanyuan,Jingyang County,on the stability of high-angle slopes containing fractures and the occurrence of major landslides in Dongfeng and Jiangliu villages.
作者
潘网生
赵恬茵
李鑫
PAN Wang-sheng;ZHAO Tian-yin;LI Xin(School of Tourism and Resources Environment,Qiannan Normal University for Nationalites,Duyun,Guizhou 558000,China;School of Civil Engineering,Shijiazhuang Tiedao University,Shijiazhuang,Hebei 050043,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2024年第6期1709-1719,共11页
Rock and Soil Mechanics
基金
黄土高原土壤侵蚀与旱地农业国家重点实验室基金课题(A314021402-202113)
中央引导地方科技发展资金项目(No.236Z5405G)
河北省自然科学基金(No.E2021210092)
黔南民族师范学院支持引进高层次人才研究专项项目(2021qnsyrc03)
黔南民族师范学院2024年度重点研究科研能力提升项目(2024zdzk07)。
关键词
黄土
优先流
连通性
微观结构
地理信息系统
loess
preferential flow
connectivity
microstructure
geographic information system(GIS)
