【作者】 王坤；

【导师】 岳丰田； 齐吉龙；

【作者基本信息】 中国矿业大学 ， 建筑与土木工程（专业学位）， 2019， 硕士

【摘要】 现阶段我国轨道交通以及地下建设不断增加,人工冻结法被广泛应用于地层的加固和止水,但冻结法施工所面临的工程环境也越来越复杂。城市轨道交通工程在施工中也遇到各类较为棘手的难题,比如如何保证上穿临近建构筑物的稳定性、如何保证不稳定地基开挖建设中的安全性等等。城市地下空间当中遍布各种建构筑物、管线、道路等,如何有效地保证地下及地面设施的安全施工十分重要。本文结合上海地铁江浦路站实际工程中拟采用的钢管冻土复合结构进行冻结施工,选定双排管棚和热水+管棚两种不同布置形式进行温度场研究,论文中利用有限元模拟和模型实验对钢管冻土复合结构温度场的发展规律进行研究。本文系统性研究了冻结温度场理论、实验与模拟研究现状,并在此基础根据钢管冻土复合结构冻结温度场最新研究成果,基于有限元软件开发不均匀数值模型下的冻结温度场计算,通过典型参数分析,得到了双排管棚布置方式下限制冻结温度场发展规律;得到热水+管棚布置方式下精准控制冻结温度场发展的规律;通过单因素分析,得到双排管棚布置方式下管棚直径、填充物导热系数、管棚间距、管棚排距、管棚与冻结管排距5个影响因子在不同冻结时间中温度场的发展趋势;得到热水+管棚布置方式下循环热水温度、热水管间距、热水管直径、热水管与管棚排距5个影响因子在不同冻结时间中温度场的发展趋势;通过正交试验分析,得到了两布置形式下各因素对钢管冻土复合结构温度场的影响和显著性分析。本文以相似准则作为理论基础,设计了双排管棚和热水+管棚两种布置方式下的冻结实验系统,并根据此系统进行物理模型实验,在相似模型实验条件下探讨了钢管冻土复合结构温度场的影响规律。将模型实验所得到的计算数据与有限元模拟数据相互比较研究,得出钢管冻土复合结构温度场发展规律基本一致。物理试验中管棚壁厚度较土体传热快且初始地温比数值模拟中的数值偏小,物理试验冻结壁厚度和温度均略大于数值模拟计算结果。本文所研究的课题对限制冻结发展的加固工程设计与施工起到一定的指导和借鉴价值。更多还原

【Abstract】 At the present stage,rail transit and underground construction are increasing in our country.Artificial freezing method is widely used to reinforce and stop water in strata.However,the engineering environment faced by freezing method construction is becoming more and more complex.Urban rail transit engineering also encounters various kinds of difficult problems in construction,such as how to ensure the stability of the adjacent structures,how to ensure the safety of unstable foundation excavation and construction,and so on.Urban underground space is full of various structures,pipelines,roads and so on.How to effectively ensure the safe construction of underground and ground facilities is very important.In this paper,combined with the freezing construction of steel pipe frozen soil composite structure to be adopted in the actual project of Jiangpu Road Station of Shanghai Metro,the temperature field of steel pipe frozen soil composite structure is studied in two different layouts: double row pipe shed and hot water + pipe shed.In this paper,the development law of temperature field of steel pipe frozen soil composite structure is studied by finite element simulation and model experiment.In this paper,the theory,experiment and Simulation of freezing temperature field are systematically studied.Based on the latest research results of freezing temperature field of steel pipe-frozen soil composite structure and the calculation of freezing temperature field under the non-uniform numerical model developed by finite element software,the development law of limiting freezing temperature field under the arrangement of double-row pipe shed is obtained through the analysis of typical parameters.+ The rule of precisely controlling the development of freezing temperature field under the arrangement of pipe shed is obtained through single factor analysis.The development trend of temperature field under different freezing time is obtained by five factors: the diameter of pipe shed,thermal conductivity coefficient of filler,spacing between pipe shed,spacing between pipe shed and freezing pipe;the circulating hot water temperature and hot water pipe under the arrangement of hot water + pipe shed.The development trend of temperature field in different freezing time was analyzed by orthogonal test,and the influence of each factor on temperature field of composite structure of steel pipe frozen soil under two layout forms and significant analysis were obtained.Based on the similarity criterion,this paper designs a freezing experimental system with two layouts of pipe shed and hot water + pipe shed.According to this system,physical model experiments are carried out,and the influence of temperature field on the composite structure of steel pipe permafrost is discussed under the similar model experimental conditions.Comparing the calculated data from the model experiment with the finite element simulation data,the temperature field development law of the composite structure of steel pipefrozen soil obtained by the two research methods is basically the same.In physical test,the thickness of pipe shed wall is faster than that of soil,and the initial ground temperature is smaller than that of numerical simulation.The thickness and temperature of freezing wall in physical test are slightly larger than that of numerical simulation.The subject studied in this paper has certain guidance and reference value for the design and construction of reinforcement engineering which restricts the development of freezing.更多还原