细/粗二元结构边坡角度与岩性特征对其阻隔降雨入渗的影响规律  

Effect of Angle and Lithology on Infiltrating to Fine/Coarse Dual-Structure Slope under Rainfall Condition

作　　者：吴庆华[1,2] 王珂 Wu Qinghua;Wang Ke(Changjiang River Scientific Research Institute,Wuhan 430010,China;Key Laboratory of Geotechnical Mechanics and Engineering of Ministry of Water Resources,Wuhan 430010,China;China Three Gorges Construction Engineering Corporation,Chengdu 610041,China)

机构地区：[1]长江水利委员会长江科学院,湖北武汉430010 [2]水利部岩土力学与工程重点实验室,湖北武汉430010 [3]中国三峡建工(集团)有限公司,四川成都610041

出　　处：《地球科学》2025年第1期311-321,共11页Earth Science

基　　金：国家自然科学基金项目(No.42072282);中央级公益性科研院所基本科研业务费项目(No.CKSF2023360/YT)。

摘　　要：土质边坡在降雨条件下易形成滑坡灾害,采用表面硬化等传统方法防止降雨入渗边坡时,存在运行过程中表面开裂导致其防护功能失效的问题.从生态优先与长期有效性角度,采用上细/下粗的非饱和二元结构地层阻隔降雨入渗防护边坡.利用系列物理模型试验,研究降雨条件下不同边坡角度(10°、20°、30°和40°)与不同地层岩性特征(亚砂土/粗砂、亚砂土/砂砾、亚砂土/圆砾和亚砂土/角砾)对其阻隔降雨入渗的影响,并提出了细/粗二元结构地层抑制降雨入渗的综合阻隔能力的评估方法.结果表明:(1)采用亮蓝示踪剂可直接观测非饱和二元结构地层对降雨入渗边坡的阻隔过程.(2)二元结构的综合阻隔能力随粗粒层粒径和不均匀系数的增加而增强.(3)无降雨条件下,增加边坡角度能促进二元结构地层排水;在降雨条件下,亚砂土/砾砂二元结构粗粒层稳定排水强度和降雨入渗综合阻隔能力均随边坡角度呈先增加后减少的规律,建议最优边坡角度范围为25°~27°.研究成果对边坡稳定治理具有重要参考价值.The occurrence of landslide is mainly caused by rainfall.Traditional treatment methods,such as spraying concrete on the surface of landslide to inhibit the penetration of rainfall on soil slopes,will fail during long-term operation resulted from failures,leading to landslides.Therefore,considering the ecological function and the long-term effectiveness of the reclamation method,this paper adopts the dual-structure of unsaturated capillary barrier layer(CBL)with fine/coarse lithology to prevent rainfall from infiltrating into the soil slope.The effects of slope(10°,20°,30°,40°)and lithological characteristics(sandy loam/coarse sand,sandy loam/gravel sand,sandy loam/pebble and sandy loam/breccia)on the infiltration of rainfall into the soil slope were investigated through a series of physical model tests.Furthermore,a new method is defined to evaluate the total capacity of the capillary barrier(CCB)of the fine/coarse bilayer.The research results show that:(1)The process of preventing rainfall from infiltrating the soil slope with brilliant blue FCF(C.I.42090)dye tracer can be observed visually.(2)CCBS increases with the increase of coarse particle diameter,which is also related to the shape of pores and coarse particles,that is,the drainage efficiency of breccia with the same particle composition is higher than that of boulders.(3)The larger the slope angle of the four types of CBLS soil,the higher the drainage speed of CBL after rainfall,and the stable drainage strength and the total barrier capacity of loam/gravel sand CBL with rainfall intensity of 4.73×10-4 cm/s,could increase firstly and then decrease with the increased slope angles.It is suggested that the design slope of CBLS is 25°-27°,in order to achieve the optimal total barrier capacity.The results of this study have a certain reference value for future landslide control.

关 键 词：边坡 二元结构 非饱和渗流 降雨 入渗控制 灾害地质学 

分 类 号：P641.2[天文地球—地质矿产勘探]