基于扩散-对流模型的海底混凝土隧道耐久寿命预测  

Durability Life Prediction of Concrete Submarine Tunnel Based on the Model of Diffusion-Convection

作　　者：张苑竹 杨佳铭 魏纲 黄森乐 ZHANG Yuanzhu;YANG Jiaming;WEI Gang;HUANG Senle(School of Engineering,Zhejiang University City College,Hangzhou 310015,China;College of Civil Engineering,Zhejiang University of Technology,Hangzhou 310023,China)

机构地区：[1]浙大城市学院工程学院,杭州310015 [2]浙江工业大学土木工程学院,杭州310023

出　　处：《材料导报》2023年第6期104-108,共5页Materials Reports

基　　金：国家自然科学基金(51878609);浙江省自然科学基金(LY21E080005)。

摘　　要：考虑海底隧道承受侵蚀性高压力海水的服役环境特点以及高性能混凝土的非饱和特性,建立了海底混凝土隧道氯离子扩散-对流传输模型和耐久寿命预测模型。以舟山沈家门海底隧道为工程背景,通过室内实验确定计算参数,采用TOUGH2软件数值模拟了环境中氯离子侵入隧道的传输过程,得到了氯离子经时传输规律,以及水头、混凝土初始饱和度、环境氯离子质量分数的作用规律,比较了扩散、饱和扩散-对流、非饱和扩散-对流预测模型的计算差异。结果表明:海底隧道腋角位置的氯离子质量分数累积最高;水头和环境氯离子质量分数与氯离子质量分数增长呈正相关,混凝土初始饱和度与氯离子质量分数增长呈负相关;按照扩散模型预测得到的隧道耐久寿命最长,按照非饱和扩散-对流模型预测得到的耐久寿命最短。Considering the service environment characteristics of submarine tunnel subjected to aggressive high pressure seawater and the unsaturated characteristics of high performance concrete,the chloride ion diffusion-convection transport model and the durability life prediction model of submarine concrete tunnel were established.Using Shenjiamen submarine tunnel in Zhoushan as the engineering background,the calculation parameters were determined through indoor experiments,and the process of environmental chloride ions intruding into the tunnel was numerically simulated by TOUGH2 software,which obtained the time-dependent law of chloride ion transmission,as well as the action law of water head,initial saturation of concrete,and mass fraction of ambient chloride ions.Then the differences between diffusion,saturated diffusion-convection,and unsaturated diffusion-convection prediction models were compared.The results show that the accumulation of chloride ion mass fraction is the highest in the axillary position of the tunnel;the head and ambient chloride ion mass fraction are positively correlated with the growth of chloride ion mass fraction,and the initial saturation of concrete is negatively correlated with the growth of chloride ion mass fraction;the durability life of the tunnel is the longest according to the diffusion model and the shortest according to the unsaturated diffusion-convection model.

关 键 词：海底隧道 非饱和混凝土 扩散-对流 氯离子 耐久寿命 

分 类 号：U459.5[建筑科学—桥梁与隧道工程]