青藏铁路北麓河段路基冻土动力参数试验分析
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摘要
冻土动力参数即是进行工程设计的依据,同时还为动力响应模拟提供必要参数。选取青藏铁路沿线粉质黏土为研究对象,通过试验分析了在不同的温度、围压、频率作用下冻土动弹性模量、动剪切模量、阻尼比的变化特性。利用等效黏弹性模型将动弹性模量(或动剪切模量)、动阻尼比与动应变幅值之间的关系具体化,并将以上函数曲线与Hardin双曲线进行拟合,确定等效黏弹性模型中的试验参数。试验发现,冻土动弹性模量与动剪切模量随温度的降低而升高,随围压、频率的升高而升高;动阻尼比随着温度降低而降低,随着围压升高而升高,随频率升高而降低。
The dynamic parameters of frozen soil provide evidence for engineering design and necessary parameters for dynamic response simulation. In this paper, the silty clay along Qinghai-Tibet Railway is chosen as the research object. This paper aims to analyze the changing features of the dynamic elastic modulus, dynamic shear modulus and damping ratio of frozen soil under different temperatures, confining pressures and frequencies. The author will make the relationship among dynamic elastic modulus(or shear modulus), damping ratio and dynamic strain amplitude more specific, by using the equivalent viscoelastic model. Besides, the author will make the above function curve close to the Hardin hyperbola, and determine the test parameters of equivalent viscoelastic model. The test found that the permafrost dynamic elastic modulus and dynamic shear modulus increase with the decrease of the temperature and increase with the increase of the confining pressure and frequency. The damping ratio decreases as temperature decreases, increases as the confining pressure increases, and decreases as the frequency increases.
The dynamic parameters of frozen soil provide evidence for engineering design and necessary parameters for dynamic response simulation. In this paper, the silty clay along Qinghai-Tibet Railway is chosen as the research object. This paper aims to analyze the changing features of the dynamic elastic modulus, dynamic shear modulus and damping ratio of frozen soil under different temperatures, confining pressures and frequencies. The author will make the relationship among dynamic elastic modulus(or shear modulus), damping ratio and dynamic strain amplitude more specific, by using the equivalent viscoelastic model. Besides, the author will make the above function curve close to the Hardin hyperbola, and determine the test parameters of equivalent viscoelastic model. The test found that the permafrost dynamic elastic modulus and dynamic shear modulus increase with the decrease of the temperature and increase with the increase of the confining pressure and frequency. The damping ratio decreases as temperature decreases, increases as the confining pressure increases, and decreases as the frequency increases.
引文
[1] 徐学祖,丁德文.冻土改造和利用的研究现状及展望[C]//第四届冻土学术会议论文集,1990:191-199.
[2]ZHANG T,BARRY R G,KNOWLES K,et al.Statistics and characterstics of permaforst and ground ice distribution in the Northern Hemisphere[J].Polar Geography,1999,23(2):147-169.
[3]王静.季冻区路基土冻融循环后力学特性研究及微观机理分析[D].长春:吉林大学,2012.
[4]高志华,石坚,罗丽娟.青藏铁路路基冻胀变形特点的研究[J].铁道建筑,2010,39(6):387-404.
[5]尹国安,牛富俊,林战举,等.青藏铁路沿线多年冻土分布特征及其对环境变化的响应[J].冰川冻土,2014,36(4):772-781.
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[7]吴志坚,王兰民,马巍,等.地震荷载作用下冻土的动力参数试验研究[J].西北地震学报,2003,25(3):210-214.
[8] 赵淑萍,朱元林,何平,等.冻土动力学参数测试研究[J].岩石力学与工程学报,2003(S2):2677-2681.
[9] 谢敏.高温冻土动荷载直剪试验研究[D].北京:北京交通大学,2014.
[10]罗飞,赵淑萍,马巍,等.分级加载下冻土动弹性模量的试验研究[J].岩土工程学报,2013,35(5):849-855.
[11]陈拓,吴志坚,车爱兰,等.机车动荷载作用下多年冻土区铁路路基动力响应的试验研究[J].地震工程与工程振动,2011,31(1):168-173.
[12] 崔颖辉.基于冻土动荷载直剪仪的高温冻土动力特性研究[D].北京:北京交通大学,2015.
[13] 石峰.动荷载条件下冻土融化固结与变形研究[D].北京:北京交通大学,2014.
[14]王大雁,朱元林,赵淑萍,等.超声波法测定冻土动弹性力学参数试验研究[J].岩土工程学报,2002(5):612-615.
[15]肖东辉,马巍,赵淑萍,等.冻土动力参数研究的成果综述与展望[J].冰川冻土,2015,37(6):1611-1626.
[2]ZHANG T,BARRY R G,KNOWLES K,et al.Statistics and characterstics of permaforst and ground ice distribution in the Northern Hemisphere[J].Polar Geography,1999,23(2):147-169.
[3]王静.季冻区路基土冻融循环后力学特性研究及微观机理分析[D].长春:吉林大学,2012.
[4]高志华,石坚,罗丽娟.青藏铁路路基冻胀变形特点的研究[J].铁道建筑,2010,39(6):387-404.
[5]尹国安,牛富俊,林战举,等.青藏铁路沿线多年冻土分布特征及其对环境变化的响应[J].冰川冻土,2014,36(4):772-781.
[6] 刘飞禹,蔡袁强,徐长节,等.循环荷载下软土动弹性模量衰减规律研究[J].浙江大学学报,2008,42(9):1479-1483.
[7]吴志坚,王兰民,马巍,等.地震荷载作用下冻土的动力参数试验研究[J].西北地震学报,2003,25(3):210-214.
[8] 赵淑萍,朱元林,何平,等.冻土动力学参数测试研究[J].岩石力学与工程学报,2003(S2):2677-2681.
[9] 谢敏.高温冻土动荷载直剪试验研究[D].北京:北京交通大学,2014.
[10]罗飞,赵淑萍,马巍,等.分级加载下冻土动弹性模量的试验研究[J].岩土工程学报,2013,35(5):849-855.
[11]陈拓,吴志坚,车爱兰,等.机车动荷载作用下多年冻土区铁路路基动力响应的试验研究[J].地震工程与工程振动,2011,31(1):168-173.
[12] 崔颖辉.基于冻土动荷载直剪仪的高温冻土动力特性研究[D].北京:北京交通大学,2015.
[13] 石峰.动荷载条件下冻土融化固结与变形研究[D].北京:北京交通大学,2014.
[14]王大雁,朱元林,赵淑萍,等.超声波法测定冻土动弹性力学参数试验研究[J].岩土工程学报,2002(5):612-615.
[15]肖东辉,马巍,赵淑萍,等.冻土动力参数研究的成果综述与展望[J].冰川冻土,2015,37(6):1611-1626.