渗流作用下三亚河口通道管幕冻结法温度场数值模拟分析  

A Numerical Analysis of the Temperature Field of the Pipe Curtain Freezing Method Under the Effect of Seepage

作　　者：卫凯 胡俊[2,3] 周杰 WEI Kai;HU Jun;ZHOU Jie(China Railway 20 Bureau Group First Engineering Co Ltd,Suzhou 215000,China;College of Civil Engineering and Architecture,Hainan University,Haikou 570228,China;Collaborative Innovation Center of Marine Science and Technology,Hainan University,Haikou 570228,China)

机构地区：[1]中铁二十局集团第一工程有限公司,江苏苏州215000 [2]海南大学土木建筑工程学院,海南海口570228 [3]海南大学海洋科技协同创新中心,海南海口570228

出　　处：《五邑大学学报（自然科学版）》2024年第1期60-69,共10页Journal of Wuyi University(Natural Science Edition)

基　　金：海南大学横向科研项目“临海环境下浅覆土长距离管幕冻结法隧道与特大深基坑安全施工保障技术研究”(HD-KYH-2022405);海南省科技厅创新研究团队项目(522CXTD511);海南大学2022年度协同创新中心科研项目(XTCX2022STB09)。

摘　　要：为得到在渗流作用下管幕冻结法温度场的变化规律,以三亚河口通道海底隧道工程初步设计为例,运用有限元数值模拟软件建立水热耦合模型,假设模型中渗流流向自左向右,通过改变模型中平均渗流速度的大小对冻结帷幕的发展、封闭性、厚度变化等进行分析.结果表明:在冻结期间,随着平均渗流速度的增大,外圈冻土帷幕的形成时间延迟,其向渗流流向偏移的程度增大,且最终稳定的冻土帷幕平均厚度减小;在冻结约14 d后,不同水头差下的冻土帷幕内部渗流速度均降至0 m/d,冻土帷幕在形成的早期受渗流作用的影响较大.鉴于原冻结方案较为保守,提出优化冻结方案:将原冻结方案外圈冻结管减少一半至48根,且调整盐水降温计划实现二次优化.对二次优化结果分有渗流与无渗流两种情形进行讨论,结果得出:优化后在渗流作用下冻土帷幕厚度约5 m,比原方案减少了2 m,既满足冻结设计要求,又提高了经济性.In order to obtain the variation law of the temperature field of the pipe curtain freezing method under the action of seepage, taking the preliminary design of the submarine tunnel of the Sanya Estuary Passage as an example, a coupling model of water and heat was established by using the finite element numerical simulation software. The development, closure and thickness change of the freezing curtain were analyzed by changing the average seepage velocity in the model, assuming that the seepage flow direction in the model was from left to right. The results showed that: during the freezing period,with the increase of the average seepage velocity,the formation time of the outer frozen curtain was delayed,its offset to the seepage flow direction increased,and the average thickness of the eventually stabilized frozen curtain decreased;after freezing for about 14 d,the internal seepage velocities of the frozen curtain with different head differences all decreased to 0 m/d,and the frozen curtain was more affected by the seepage flow in the early stage of its formation.In view of the conservative nature of the original freezing scheme, an optimized freezing scheme was proposed: the number of freezing tubes in the outer ring of the original freezing scheme were reduced by half to 48, and the brine cooling plan was adjusted to achieve secondary optimization. The results of the secondary optimization were divided into two situations: seepage flow and no seepage flow.After optimization, the thickness of frozen soil curtain under the action of seepage was about 5 m,a decrease of 2 m compared with the original program,which not only meets the requirements of the freezing design,but is also more economical.

关 键 词：渗流作用 管幕冻结 有限元数值模拟 水热耦合 冻土帷幕 

分 类 号：TU472[建筑科学—结构工程]