非饱和导排结构控制降雨入渗的边坡物理模型试验

发布时间：2018-05-11 22:42

本文选题：二元结构 + 边坡　；参考：《岩土工程学报》2017年01期

【摘要】：膨胀土渠坡失稳是影响南水北调中线供水工程安全性的重要因素之一,而对其边坡进行防渗处理是解决膨胀土边坡失稳的有效途径。针对传统边坡防渗处理方法(面板与土工布覆盖等)存在生态功能弱以及使用寿命短等不足,开展了非饱和导排结构的边坡防渗效果的物理模型试验研究。利用土壤剖面负压动态监测数据,采用非饱和渗流理论,在不同降雨强度与不同初始含水量条件下,对比分析了两种非饱和导排结构即细/粗粒二元结构和粗粒单一结构,控制降雨入渗边坡的效果。研究结果表明:在降雨强度为4.18×10-4 cm/s的情况下,二元结构能有效阻止降雨入渗;且细粒层初始含水量越低,其储水能力越强,二元结构控制降雨入渗的效果相对越好。在降雨强度为1.72×10-4,4.18×10-4,4.97×10-4 cm/s的情况下,粗粒层单一结构对降雨入渗边坡均具有一定的控制作用,但有5.6%~10.7%的降雨从模型底部排出,存在入渗风险。总体上,从排水渗流控制效果与生态功能角度考虑,二元结构明显优于单一结构。研究成果可为解决南水北调膨胀土边坡以及其它工程边坡的渗流控制问题提供技术支撑。
[Abstract]:The instability of expansive soil channel slope is one of the important factors affecting the safety of water supply project in the middle route of South-to-North Water transfer Project, and the effective way to solve the instability of expansive soil slope is to deal with the seepage prevention of the slope. Aiming at the shortcomings of the traditional anti-seepage treatment methods (such as face slab and geotextile covering etc.) in ecological function and short service life, a physical model test study on the seepage prevention effect of unsaturated guiding and drainage structure is carried out. Based on soil profile negative pressure dynamic monitoring data and unsaturated seepage theory, two unsaturated conductance structures, fine / coarse grain binary structure and coarse grain single structure, are compared and analyzed under different rainfall intensity and different initial water content. The effect of controlling rainfall infiltration slope. The results show that when the rainfall intensity is 4.18 脳 10 ~ (-4) cm/s, the binary structure can effectively prevent rainfall infiltration, and the lower the initial water content of fine layer is, the stronger the water storage capacity is, and the better the effect of binary structure is in controlling rainfall infiltration. When the rainfall intensity is 1.72 脳 10 ~ (-4) ~ (-4) ~ 4.18 脳 10 ~ (-4) ~ (-4) cm/s, the single structure of coarse grain layer can control the rainfall infiltration slope to some extent, but 5.610. 7% of the rainfall is discharged from the bottom of the model, and the infiltration risk exists. On the whole, considering the effect of seepage control and ecological function, the binary structure is obviously superior to the single structure. The research results can provide technical support for solving the seepage control problem of expansive soil slope and other engineering slopes of South-to-North Water transfer Project.
【作者单位】：长江科学院水利部岩土力学与工程重点实验室;中国地质调查局河北省地下水污染机理与修复重点实验室;中国地质大学教育部长江三峡库区地质灾害研究中心;中交第二公路勘察设计研究院有限公司;
【基金】：中国地质科学院水文地质环境地质研究所开放性基金项目(KF201508) 中国地质大学教育部长江三峡库区地质灾害研究中心开放性基金项目(TGRC201403) 国家自然科学基金项目(41402213,51279016) 国家“十二五”科技支撑计划(2011BAB10B04)
【分类号】：TV223

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