水下隧道混凝土中水分运移  

Water Penetration in Underwater Concrete Tunnel

作　　者：张苑竹[1] 李晓珍[2] 魏新江[1] 俞国骅 李伟光[1] 黄英省[1] 

机构地区：[1]浙江大学城市学院土木工程系,杭州310015 [2]金华职业技术学院建工学院,浙江金华321017

出　　处：《硅酸盐学报》2015年第4期368-375,共8页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金项目(51208463);浙江省自然科学基金项目(LY12E08012)

摘　　要：分析了水下隧道非饱和混凝土中水分运移的理论模型;实验获得了混凝土孔隙率、初始饱和度、饱和水力传导系数和混凝土等温吸附曲线等基本参数,通过室内加压渗流实验得到了水分运移深度随加压时间、水压、初始饱和度和水胶比的变化规律;采用TOUGH2软件数值模拟了水分等温水平运移中流速和饱和度的变化规律和分布特征。研究认为水下隧道混凝土中水分受外水压力和毛细吸力共同驱动;外水压力越大、初始饱和度越小,水分运移速度越快、水分运移深度越大;随着饱和度提高水分润湿锋面前移,混凝土内完全饱和区域逐渐扩大,压力差逐渐取代毛细吸力成为水分运移的控制因素。A theoretical model of water penetration in unsaturated concrete of underwater tunnel was analyzed.The basic parameters including porosity,initial saturation,saturated hydraulic conductivity and isothermal adsorption curves of concrete were determined through lab-scale experiments.The variation of penetration depth with pressuring time,water pressure,initial saturation and water-binder ratio were investigated through penetration tests under external water pressure.In addition,the change and distribution of the velocity of flow and saturation of isothermal horizontal flow were numerically analyzed using a software named TOUGH2.The results show that the water penetration is co-driven by the combined action of water pressure and matric suction in an underwater concrete tunnel.The hydraulic pressure is larger and the initial saturation is smaller,the velocity of flow is faster which causes the greater penetration depth.With the increase of water saturation of the wetting front moves,fully saturated zone gradually expanded.Consequently,the hydraulic pressure difference becomes the control factor of moisture migration instead of matric suction.

关 键 词：水下隧道 非饱和混凝土 水分运移 外水压力 

分 类 号：U459.5[建筑科学—桥梁与隧道工程]