高温冻土动荷载直剪试验研究

发布时间：2018-06-25 11:02

本文选题：高温冻土 + 动荷载　；参考：《北京交通大学》2014年硕士论文

【摘要】：摘要：冻土具有特别的热学力学性质和物理性质,地震作用下冻土的动力学参数又具有其特殊性,因此确定地震荷载下冻土的动力学参数是一个极其关键的问题,而高温冻土更为敏感,其动力学参数研究更是冻土动力学研究的重要组成部分。本文总结和分析了大量国内外对动荷载条件下冻土动力学特性的研究情况,在此基础上,针对冻土动力学的应力应变特性和动力学参数研究方法,使用北京交通大学岩土实验室自主设计的动荷载直剪试验仪,开展了一系列动荷载直剪试验。试验用土为哈大客运专线哈沈段的路基素填土,本文通过一系列动荷载直剪试验研究了在不同控制参数(温度、法向应力、振动次数、加载幅值等)下土体的动力学特性,分析总结了高温冻土在模拟地震荷载作用下的应力和应变随时间变化的规律,分析不同控制参数下剪切位移的增长情况；分析了温度和法向应力对冻土动强度的影响情况；并提取出应力-应变滞回曲线,进而计算出冻土的动剪切模量和动阻尼比,并对动剪切模量和动阻尼比的分布情况进行分析；计算出二者的标准值进而研究二者随温度、法向应力、振动次数、加载级数、加载幅值等不同参数变化的规律。本文利用动荷载直剪仪进行试验,为冻土的动力学参数测定提供了一种新的选择。
[Abstract]:Abstract: frozen soil has special thermal and physical properties, and the dynamic parameters of frozen soil under earthquake have its particularity, so determining the dynamic parameters of frozen soil under earthquake load is an extremely critical problem. High temperature frozen soil is more sensitive, and the study of its dynamic parameters is an important part of frozen soil dynamics research. In this paper, a large number of researches on the dynamic characteristics of frozen soil under dynamic load are summarized and analyzed. On this basis, the stress-strain characteristics and dynamic parameters of frozen soil dynamics are studied. A series of dynamic load direct shear tests were carried out by using the dynamic load direct shear test instrument designed by the geotechnical laboratory of Beijing Jiaotong University. In this paper, the dynamic characteristics of soil under different control parameters (temperature, normal stress, vibration frequency, loading amplitude, etc.) are studied through a series of direct shear tests of dynamic load. The variation law of stress and strain with time under simulated earthquake load, the growth of shear displacement under different control parameters, the influence of temperature and normal stress on the dynamic strength of frozen soil are analyzed and summarized. The stress-strain hysteretic curve was extracted, and the dynamic shear modulus and dynamic damping ratio of frozen soil were calculated, and the distribution of dynamic shear modulus and dynamic damping ratio were analyzed. The variation of normal stress, vibration times, loading series, loading amplitude and so on. This paper presents a new choice for the determination of the dynamic parameters of frozen soil by using the dynamic load direct shear apparatus.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P642.14;U212.22

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