深部人工冻土力学特性及分数阶导数西原模型研究

发布时间：2018-01-09 22:23

  本文关键词：深部人工冻土力学特性及分数阶导数西原模型研究　出处：《安徽理工大学》2014年硕士论文　论文类型：学位论文

  更多相关文章： 冻土 本构模型 粒子群 分数阶导数 蠕变

【摘要】：近年来,随着寒区工业和农业的快速发展以及冻结法施工技术在煤矿冻结法凿井、越海隧道、越江隧道、地铁等工程上的推广和应用。在工程中出现了各种工程问题如：煤矿透水、隧道的坍塌、海底隧道透水等,这些问题造成了生产停工,列车中断行车,巨大的经济损失等问题,给社会带来了巨大的影响；人们也日益认识到了解决冻土问题的紧迫性,因此,冻土的研究已成为重要的研究课题；本文正是基于此对冻土的弹塑性本构模型及粒子群分数阶导数的西原模型进行了研究。本文研究成果无论是在理论上还是在解决实际工程问题均具有重要的指导意义。 利用安徽理工大学冻土研究所自行研制的W3Z—200型电液伺服三轴试验机冻结砂质黏土进行力学试验,对原状土和重塑土进行了不同温度(-5℃、-10℃、-15℃)和不同围压(1MPa、2MPa、3MPa)条件下的三轴剪切试验,获得了应力—应变曲线及三轴剪切强度,通过比较可以发现重塑土的强度低于原状土的强度。原状土呈应变软化型,重塑土属于强应变硬化型。基于冻土的破坏准则、屈服准则、相关联的流动法则,同时建立了修正剑桥模型的冻土的屈服函数,确立了冻土的弹塑性本构模型,为了验证本构模型的合理性,对本构模型进行了采用隐式函数积分格式的程序求解,验证了本构模型的合理性。 利用安徽理工大学冻土研究所自行研制的WDT—100型型微机控制电液伺服冻土单轴试验机进行了冻结砂质黏土的蠕变力学试验,分别进行了三个温度(-5℃、-10℃、-15℃)和三个加载系数(0.3σs、0.5σs、0.7σs(σs--单轴强度)下的单轴蠕变试验,获得了应力-应变曲线。基于传统的西原模型不能描述冻土加速流变阶段的变形,运用分数阶导数的性质,建立了分数阶导数的西原模型,同时对经典的西原模型和分数阶导数进行了数值拟合,在对分数阶导数的西原模型拟合时,用粒子群的方法进行了优化,验证了粒子群分数阶导数的西原模型在拟合冻土加速流变过程中的优越性。
[Abstract]:In recent years, with the rapid development of industry and agriculture in cold region and freezing construction technology in coal mine freezing method sinking, cross-sea tunnel, cross-river tunnel. The extension and application of subway and other projects. In the project, there are various engineering problems such as coal mine water permeability, tunnel collapse, submarine tunnel water permeability, these problems have caused production stoppage and train traffic interruption. The huge economic loss and other problems have brought great influence to the society; People are also increasingly aware of the urgency of solving the problem of frozen soil, therefore, the study of frozen soil has become an important research topic; In this paper, the elastoplastic constitutive model of frozen soil and the westerline model of fractional derivative of particle swarm are studied. The research results in this paper have important guidance both in theory and in solving practical engineering problems. Meaning. The mechanical tests of frozen sandy clay with W3Z-200 electro-hydraulic servo triaxial testing machine developed by the Institute of Frozen soil of Anhui University of Technology were carried out. The undisturbed soil and remolded soil were tested at different temperatures (-5 鈩，

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