上海软土地层中地铁联络通道冻结法施工的温度场发展特性  

Temperature Field Development Characteristics of Frozen Method Construction for Metro Link Passages in Shanghai Soft Soil Stratum

作　　者：赵昊楠 夏才初 王兴开[1] ZHAO Haonan;XIA Caichu;WANG Xingkai(School of Civil Engineering,Shaoxing University,312099,Shaoxing,China;School of Civil Engineering,Tongji University,200092,Shanghai,China)

机构地区：[1]绍兴文理学院土木工程学院,绍兴312099 [2]同济大学土木工程学院,上海200092

出　　处：《城市轨道交通研究》2024年第1期80-86,共7页Urban Mass Transit

基　　金：国家自然科学基金面上项目(51778475)。

摘　　要：[目的]为了在冻结法施工前预先判断冻结壁的发展情况,验证设计的合理性,从而科学地指导工程施工,需要研究上海地铁联络通道在软土地层中冻结法施工的温度场发展规律,并提出检验指标及经济指标。[方法]以上海轨道交通15号线某区间联络通道为背景,对冻结壁厚度、土层温度、盐水温度及冻结过程进行分析,通过ABAQUS有限元软件建立全地层三维数值模型,预测冻结温度场发展特性,并与现场实测温度数据进行验证。[结果及结论]黏土层冻结帷幕平均发展速度为54.535 mm/d,粉质黏土层冻结帷幕平均发展速度为52.450 mm/d,黏土层比粉质黏土层冻结效果好;由于冻结管端头截面冻结效果较弱,以该截面处弱侧冻结壁厚度和平均温度作为冻结效果的检验指标,降低强度破坏可能性;盐水温度对冻结壁厚度发展的影响随温度的降低而减弱,其中-35~-30℃时经济效益最高;模拟结果与实测数据总体降温趋势一致,可较为真实地反映实际工程。[Objective]In order to predict the development of the frozen wall before the frozen method construction and validate the rationality of the design,providing a scientific guidance for engineering construction,it is necessary to study the temperature field development law of frozen method construction for Shanghai Metro link passages in soft soil stratum,and propose evaluation and economic indicators.[Method]Taking an interval of Shanghai Rail Transit Line 15 as engineering background,the frozen wall thickness,soil temperature,brine temperature,and freezing process are analyzed.A three-dimensional numerical model of the entire stratum is established using ABAQUS finite element software to predict the development characteristics of the frozen temperature field and verify it with field-measured temperature data.[Result&Conclusion]The average development speed of the clay layer frozen curtain is 54.535 mm/day,while the average development speed of the silty clay layer frozen curtain is 52.450 mm/day,indicating a better freezing effect of the former.Considering the relatively weak freezing effect at the end profile of the freezing pipe,the thickness of the weak-side frozen wall and the average temperature at that profile are adopted as the freezing effect evaluation indicators,thereby reducing the possibility of structural damage.The influence of brine temperature on the development of frozen wall thickness weakens with decreasing temperature,with the highest economic benefit observed between-30℃and-35℃.The simulation results are consistent with the overall cooling trend of the field-measured data,providing a relatively realistic reflection of the actual construction process.

关 键 词：地铁隧道 冻结法 数值模拟 联络通道 瞬态温度场 

分 类 号：U455.49[建筑科学—桥梁与隧道工程]