林昀昭, 简文彬, 豆红强, 等. 2022. 基于电导性能的原状土柱降雨入渗规律研究[J]. 工程地质学报, 30(2): 394-406. doi: 10.13544/j.cnki.jeg.2021-0744.
    引用本文: 林昀昭, 简文彬, 豆红强, 等. 2022. 基于电导性能的原状土柱降雨入渗规律研究[J]. 工程地质学报, 30(2): 394-406. doi: 10.13544/j.cnki.jeg.2021-0744.
    Lin Yunzhao, Jian Wenbin, Dou Hongqiang, et al. 2022. Rainfall infiltration mechanisms of soil columns under conductivity[J]. Journal of Engineering Geology, 30(2): 394-406. doi: 10.13544/j.cnki.jeg.2021-0744.
    Citation: Lin Yunzhao, Jian Wenbin, Dou Hongqiang, et al. 2022. Rainfall infiltration mechanisms of soil columns under conductivity[J]. Journal of Engineering Geology, 30(2): 394-406. doi: 10.13544/j.cnki.jeg.2021-0744.

    基于电导性能的原状土柱降雨入渗规律研究

    RAINFALL INFILTRATION MECHANISMS OF SOIL COLUMNS UNDER CONDUCTIVITY

    • 摘要: 我国东南沿海地质环境复杂脆弱,由台风暴雨引发的滑坡频频发生。雨水入渗到土体内可能导致坡体变形,进而产生滑坡、泥石流等灾害。以福建三明岩兜滑坡为研究对象,通过自行研制的人工降雨土柱入渗试验装置,对研究区滑坡的残积土柱进行了不同降雨强度下(20 mm·h-1、60 mm·h-1)的累次循环降雨实验,考虑了不同降雨量、降雨历时和雨停时间等工况,获得了干湿循环下土柱含水率、电阻率以及基质吸力变化等丰富的降雨入渗试验数据,并与现场原型测试结果验证。研究结果表明:(1) 累次降雨中,土柱上部传感器含水率峰值随着干湿循环次数增加缓慢降低,深部的土体则在累次降雨后,土体含水量逐渐累积,含水率峰值缓慢提高。(2) 原状土柱土体具有非均质性,不同深度土体电阻率大小不一。电阻率响应时间与含水率响应时间具有高度相关性,含水率变化时电阻率也几乎同时产生变化,但两者变化趋势相反。(3) 基质吸力在累次降雨雨停阶段回升缓慢,多次降雨过程中,由于前次降雨中留下的水分未完全排干,基质吸力在多次降雨的作用下降到0 kPa。(4) 基于Keller改进的Archie拓展模型对研究区土体电阻率含水率进行拟合,并用实测数据进行验证,误差较小。进一步结合Archie拓展模型与Green-Ampt、Philip入渗模型,得到基于电阻率的Green-Ampt与Philip入渗模型。研究成果有助于进一步揭示研究区降雨作用下坡残积土的电阻率演化规律,揭示坡残积土坡在累次降雨下的水分入渗规律,对台风暴雨型滑坡稳定性分析及监测预警具有重要的理论及实际意义。

       

      Abstract: The geological environment of China's southeast coast is complex and fragile,with frequent landslides triggered by typhoons and rainstorms. The key factor that leads to the deformation of the slope body,then landslide and mudslide is the rainwater infiltration into the soil. This paper studies the landslide in Yandou Village. It is located in the east of Fujian Province. The study uses a self-developed artificial rainfall soil columns infiltration experiment device. It considers different rainfall,rainfall duration,rainfall interval time,and other working conditions. It conducts different cumulative cyclic rainfall experiments on the slope residual soil of landslides at different rainfall intensities(20 and 60 mm·h-1). The experiments give the rainfall infiltration data,including changes in water content,resistivity,and matric suction of soil under drying and wetting circles. The analysis of the test results show the following findings. (1) Under cumulative rainfall circumstances,the peak water content of the upper soil slowly decreases with the increase of wet and dry cycles times,while the deeper soil gradually accumulates water content and the peak water content slowly increases. (2) The soil columns feature heterogeneity. Different depths of soil show various resistivity. There is a highly correlation between the resistivity response time and the water content response time. The resistivity changes almost simultaneously when the water content changes,but these changing indicators are on the contrary. (3) The matric suction represents a very limited recovery during the rain-stopping phase of the cumulative rainfall. From the second rainfall,due to the water of the last rainfall still remaining in the soil,the matric suction drops to 0 kPa after cumulative rainfall. (4) The errors can be smaller using the expansion Archie model modified by Keller to conduct resistivity and water content fitting in the research area. This paper combined the expansion Archie model,the Green-Ampt model,and the Philip infiltration model to obtain the Green-Ampt and Philip infiltration model based on resistivity. This provides a new measurement perspective for soil infiltration with practical value. The results of this study contribute to exploring further the resistivity evolution of slope residual soils under the action of typhoons and rainstorms in the research area. In addition,the achievements reveal rainfall infiltration mechanisms of slope residual soil under cumulative rainfall circumstances that are of important theoretical and practical significance to analyze the stability of typhoon and rainstorm type landslides and to monitor and early warning activities.

       

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