吸水土工布对路基湿度控制效果的数值模拟  

Numerical simulation study on the effect of wicking-geotextile on humidity control of subgrade

作　　者：马川义 冯豪杰 蒋红光 侯天新 姚占勇 杨为民 MA Chuanyi;FENG Haojie;JIANG Hongguang;HOU Tianxin;YAO Zhanyong;YANG Weimin(Shandong High-Speed Co.Ltd.,Jinan 250014,Shandong,China;School of Qilu Transportation,Shandong University,Jinan 250002,Shandong,China;School of Transportation engineering,Tongji University,Shanghai 201804,China)

机构地区：[1]山东高速集团有限公司,山东济南250014 [2]山东大学齐鲁交通学院,山东济南250002 [3]同济大学交通运输工程学院,上海201804

出　　处：《山东大学学报（工学版）》2024年第4期141-149,共9页Journal of Shandong University（Engineering Science）

基　　金：山东省自然科学基金资助项目(ZR2021ME103);山东省工业和信息化厅企业技术创新项目(202060804178);山东高速集团有限公司((2020)-sdhs-gsjt-020)。

摘　　要：针对我国典型的粉质黏土填料路基,提出采用新型吸水土工布来控制细粒土路基内部湿度,通过对比铺设吸水土工布前后路基内部体积含水率和基质吸力的空间分布,评价吸水土工布对路基湿度的控制效果。基于压力板仪等室内试验获得吸水土工布水力参数,通过COMSOL有限元软件建立路基水汽迁移分析模型,获得不同水位条件下(2、4、6、8 m)路基内部体积含水率和基质吸力的空间分布特征,分析路基内部水分迁移模式和吸水土工布的吸排水机理。结果表明:新型吸水土工布具有较强的亲水性、较低的持水性和较高的水平渗透性;吸水土工布对路基湿度具有较好的控制效果,土工布界面上下的含水率和基质吸力发生明显突变;相比于无土工布路基,4~8 m处地下水位吸水土工布上方土体体积含水率显著降低7.6%~9.6%,基质吸力增加2~2.3倍,路基动态回弹模量提高23.2%~43.6%;吸水土工布凭借形成的基质吸力差和自身的水平导水能力,可快速吸排出非饱和土中的弱结合水。水土工布可有效控制毛细水上升导致的路基湿化,并能提高路基的支撑能力。For typical silty clay filler subgrade in China,a new type of wicking geotextile was proposed to control the humidity of fine-grained soil subgrade.And the control effect of wicking geotextile on the humidity of subgrade under different water tables was evaluated by comparing the spatial distribution of internal volume moisture content and matrix suction before and after laying wicking geotextiles.Hydraulic parameters of wicking geotextile were obtained based on pressure plate test.The finite element software COMSOL was used to establish the water vapor migration analysis model,obtaining the spatial distribution characteristics of internal volume moisture content and matrix suction of subgrade under different water level conditions(2,4,6,8 m),analyzing the internal water migration pattern of the subgrade and the suction and drainage mechanism of the wicking geotextile.The results showed that the wicking geotextile had strong hydrophilicity,low water holding capacity and high-level permeability,the wicking geotextile had a good control effect on the subgrade humidity,and the water content and matric suction of the geotextile interface had obvious changes. Compared with the non-geotextile subgrade, the water content of the soil above the geotextile wassignificantly reduced by 7.6%-9.6%, the matric suction was increased by 2-2.3 times, and the dynamic resilience modulus of thesubgrade was increased by 24.4%-43.9%. The wicking geotextile could quickly absorb and discharge weakly bound water inunsaturated soil by virtue of the poor matric suction formed and its own horizontal water conductivity. The wicking geotextile couldeffectively control the wetting of the subgrade caused by the rise of Subgrade humidification, and could improve the bearing capacityof the subgrade.

关 键 词：道路工程 吸水土工布 数值模拟 湿度控制 细粒土 基质吸力 

分 类 号：U416.1[交通运输工程—道路与铁道工程]