【作者】 姜波；

【导师】 胡向东；

【作者基本信息】 同济大学 ， 结构工程， 2006， 硕士

【摘要】 隧道联络通道冻结施工过程中,管片等隧道结构均暴露在外界空气环境中,非常容易散热,会影响附近土层的冻结速度,从而影响冻土帷幕的整体稳定性和封水性。本文综合应用现场实测、数值模拟、对比分析等方法就管片散热对隧道联络通道施工的影响做出了深入分析,主要研究内容包括: (1) 管片散热对冻结土体温度场影响的现场测试 通过施工现场的监测,确定管片周围冻结土体的实际温度以及冻土帷幕的实际厚度并与远离管片部分土体的冻结状况进行对比,研究管片散热在宏观结果上对冻结土体性状的影响。 (2) 管片散热对冻结土体温度场的三维有限元分析 在管片散热的影响下,土体的冻结过程不再是平面内的热传导问题,必须建立冻结过程的三维模型对管片散热进行深入的分析,并对这种分析的方法作出总结与探讨,使其能更好的应用于今后的设计施工中。 (3) 减轻管片散热对冻结效果影响的措施 通过理论计算和实测分析,研究与管片散热相关的各种因素,在此基础上提出相应的减轻管片散热影响的措施,并对各种措施的适用性作出分析。更多还原

【Abstract】 Ground freezing is widely employed in the construction of cross passage in shield tunnels. With horizontal freezing pipes driven through the segments, cold fluids are supplied to the target ground for its freezing. But segments are usually naked to the air with a higher temperature in the tunnel, and this kind of exposure will induce heat emission that decreases the freezing degree of the ground, brings construction risks, and even leads to the project’s failure. To get full understanding of the mechanism of this side effect, a monitoring system detecting the temperature of frozen ground was established in the cross passage construction by freezing method in Shanghai East Fuxing Road tunnel. On basis of temperature field data it provided and the theory of heat transfer, a three dimensional model is presented in this paper to simulate the heat emission of the segments, and its impact on the temperature distribution of the ground can be figured out. This solution is helpful for the similar projects. Then, based on the analysis of the factors concerning to the heat emission of the segments, several methods are presented to reduce the side effects of the heat emission, and analysis of the applicability of these methods is also carried out.更多还原