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D0:10.16285j.rsm.2011.s1.034 文章墙号:1000-7598(20111增刊1一0309-05 土体一维冻结问题温度场半解析解 周扬,周国庆 (1.中国矿业大学深都岩士力学与地下工程国家重点实验室,江苏徐州208:2中国矿业大学力学与建筑工程学院。江苏徐州26) 摘要:针对土体的一维冻结过程,采用考虑土体冻结状态下未冻水存在的等效热容模型,建立了其温度场计算的半解析方 法,并与相关文献中的数值解进行了对比,验证了方法的正确性。对等效热容模型与显热容模型进行了对比,计算结果表明: 在腾态阶段,显热容模型计算的冻结锋面推进速度较等效热容模型慢:而在接近稳态阶段,显热容模型计算的冻土区厚度较 等效热容模型厚。在冻结诱导水流较弱的情形下,土体冻结状态下的持水特性越好,采用显热容模型进行温度场计算产生的 误差越显著,并且其计算结果应用于人工冻结设计是偏于不安全的。 关使词:土壤冻结:温度场:半解析解,等效热容模型:显热容模型:未冻水 中图分类号:TU2 文献标识码:A Semi-analytical solution for temperature field of one-dimensional soil freezing problem ZHOU Yang.ZHOU Guo-qing Abstraet:In order to calculate the temperature of the one-dimensionl soil freezing process.the equivalent heat capacity model which considers the nfrz water con has been applied and the semi-analytical solutiofor the temperature field has been obtained.Thesolution procedure has been based ontheFourier method,and the solution has beenonfed by comparing with the numerical solution in some references.The comparison between the equivalent heat capacity model and the apparent heat capacity model has been made,and the resu indicate that,during the transistage,the advancing velocity of the freezing front calculated rom the apparent heat capacity model is smaller than that of the quivalent heat capacity model,during the steady stage.the ckness of the frozen zone calculated from the apparent heat capacity model is larger than that of the equivalent heat capacity mode on that the water model is used to calculate the temperature f arger the error gets ate the temperature field,and the results are unsafe 1引言 对于温度场的计算模型,最完善的是综合考虑 温度场、水分场、应力场等耦合作用的模型,如刚 无论是寒区工程还是冻结法施工均不可避免 性冰模型、水-热-力耦合模型等,这些模型一般 地遇到土壤的冻结,土壤冻结过程中温度场的计算 不适合用于工程计算。常用于工程计算的模型是显 具有重要的意义 是 工地层冻结技术 论研究的 热容模型,该模型将土体的冻结视为 般的相变 基础,同时也是运用冻结法进行设计与施工的主要 导热过程,许多商业软件计算土壤冻结温度场均是 依据四。 基于该模型。 学整金重点项目(o5053400):国家白然科学基金面上项目(No.4071021)国家科技计划重点项目(0.2006BAB16B01 1994-2016 China Academie Journal Eleetronic Publishing House.All rights reserved. http://www.cnki.ne第 32 卷增刊 1 岩 土 力 学 Vol.32 Supp.1 2011 年 4 月 Rock and Soil Mechanics Apr. 2011 收稿日期:2010-11-04 基金项目:国家自然科学基金重点项目(No. 50534040);国家自然科学基金面上项目(No. 40471021);国家科技计划重点项目(No. 2006BAB16B01); 中国矿业大学青年科研基金(No. 2009A007)。 第一作者简介:周扬,男,1982 年生,博士,讲师,主要从事冻土物理学方面的研究。E-mail:tod2006@126.com 文章编号:1000-7598 (2011)增刊 1-0309-05 土体一维冻结问题温度场半解析解 周 扬,周国庆 (1. 中国矿业大学 深部岩土力学与地下工程国家重点实验室,江苏 徐州 221008;2. 中国矿业大学 力学与建筑工程学院,江苏 徐州 221116) 摘 要:针对土体的一维冻结过程,采用考虑土体冻结状态下未冻水存在的等效热容模型,建立了其温度场计算的半解析方 法, 并与相关文献中的数值解进行了对比,验证了方法的正确性。对等效热容模型与显热容模型进行了对比, 计算结果表明: 在瞬态阶段,显热容模型计算的冻结锋面推进速度较等效热容模型慢;而在接近稳态阶段,显热容模型计算的冻土区厚度较 等效热容模型厚。在冻结诱导水流较弱的情形下,土体冻结状态下的持水特性越好,采用显热容模型进行温度场计算产生的 误差越显著,并且其计算结果应用于人工冻结设计是偏于不安全的。 关 键 词:土壤冻结;温度场;半解析解; 等效热容模型;显热容模型;未冻水 中图分类号:TU 2 文献标识码:A Semi-analytical solution for temperature field of one-dimensional soil freezing problem ZHOU Yang, ZHOU Guo-qing (1. State Key Laboratory for Geomechanics and Deep Underground Engineering, China University of Mining & Technology, Xuzhou, Jiangsu 221008, China; 2. School of Mechanics & Civil Engineering, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China) Abstract: In order to calculate the temperature of the one-dimensional soil freezing process, the equivalent heat capacity model which considers the unfrozen water content has been applied; and the semi-analytical solution for the temperature field has been obtained. The solution procedure has been based on the Fourier method, and the solution has been confirmed by comparing with the numerical solution in some references. The comparison between the equivalent heat capacity model and the apparent heat capacity model has been made; and the results indicate that, during the transient stage, the advancing velocity of the freezing front calculated from the apparent heat capacity model is smaller than that of the equivalent heat capacity model; during the steady stage, the thickness of the frozen zone calculated from the apparent heat capacity model is larger than that of the equivalent heat capacity model. Considering the situation that the water flow induced by the freezing process is weak, then the better the soil freezing characteristic is, the larger the error gets when the apparent heat capacity model is used to calculate the temperature field; and the results are unsafe for the design of the artificial ground freezing engineering. Key words: soil freezing; temperature field; semi-analytical solution; equivalent heat capacity model; apparent heat capacity model; unfrozen water 1 引 言 无论是寒区工程还是冻结法施工均不可避免 地遇到土壤的冻结,土壤冻结过程中温度场的计算 具有重要的意义,是人工地层冻结技术理论研究的 基础,同时也是运用冻结法进行设计与施工的主要 依据[1]。 对于温度场的计算模型,最完善的是综合考虑 温度场、水分场、应力场等耦合作用的模型,如刚 性冰模型[2]、水-热-力耦合模型[3]等,这些模型一般 不适合用于工程计算。常用于工程计算的模型是显 热容模型[4],该模型将土体的冻结视为一般的相变 导热过程,许多商业软件计算土壤冻结温度场均是 基于该模型。 DOI:10.16285/j.rsm.2011.s1.034
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