路基土体“锅盖效应”的数值模拟分析

发布时间：2018-06-13 13:07

本文选题：非饱和土 + 锅盖效应　；参考：《岩土力学》2017年06期

【摘要】：基于对道面下路基土体中"锅盖效应"形成机制的定性认识,依据非饱和土中气液传输及热传导多场耦合理论并考虑水的气液相转换,建议了对此问题进行分析的数学模型。采用有限元方法对道面下路基一维土柱进行模拟分析,揭示了土中水和水蒸气在变温作用下的运移及相变规律,分析了"锅盖效应"形成条件和影响因素。数值结果显示,土质和温度分布对路基土发生"锅盖效应"有较大影响。粉土路基较黏土或砂土路基更易形成水分聚集;路基顶部温度较路基深处温度低时,在温度作用下易引起路基土的"锅盖效应"。这些结果可为进一步研究道路工程中的"锅盖效应"提供参考。
[Abstract]:Based on the qualitative understanding of the formation mechanism of "pot cover effect" in roadbed soil under the pavement, based on the coupling theory of gas-liquid transport and heat conduction in unsaturated soil and considering the gas-liquid phase conversion of water, a mathematical model for analyzing this problem is proposed. The one-dimensional soil column under roadbed is simulated by finite element method. The migration and phase transition of water and steam in soil under the action of variable temperature are revealed, and the forming conditions and influencing factors of "pot cover effect" are analyzed. The numerical results show that the soil quality and temperature distribution have great influence on the "pot cover effect" of subgrade soil. Silt subgrade is easier to gather water than clay or sandy subgrade, and the temperature of the top of roadbed is lower than that of deep subgrade, so it is easy to cause "pot cover effect" of roadbed soil under the action of temperature. These results may provide a reference for further study of the "pot cover effect" in road engineering.
【作者单位】：清华大学土木工程系土木工程安全与耐久教育部重点试验室;
【基金】：国家重点基础研究发展计划(973计划)(No.2014CB047003) 国家自然科学基金项目(No.41272279)~~
【分类号】：U416.1

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