动力荷载长期作用下冻土振陷模型试验研究
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摘要
基于低温动三轴试验资料,研究了青藏铁路北麓河粉质黏土在往返长期加荷作用下的变形特征。在不同温度、动应力幅、频率、围压条件下考察冻土轴向残余应变与振次的试验关系曲线,建立了冻土振陷模型,并讨论了模型参数及其影响因素。研究表明,(1)模型参数受拟合所采用的振次水平影响较大,参数B(黏塑流蠕变率)随振次的增加而迅速减小,参数C(蠕变衰减系数)随振次的增加而迅速增大;(2)除迅速破坏的试件外,当振次达到一定临界值以后,B、C两参数都逐渐趋于稳定;相同振次水平下B、C参数均随温度升高、动应力幅值增大、围压增高而增大,随频率的增加而减少,且频率大于6Hz时对参数影响很小。此项研究对于合理预测动力荷载长期作用下由冻土残余变形而产生的沉降量具有重要意义,且为冻土动力学研究积累基础试验成果。
Based on dynamic triaxial test at low temperature,deformation behavior of silty clay sampled from Beiluhe section of Qinghai-Tibet Railway under long-term cyclic loading is studied.At different negative temperatures,frequency,confining pressure and water content,relation curves between residual strain and vibration times of frozen soil are investigated;vibration excited subsidence model is built;and its parameters along with influential factors are discussed.The results demonstrate that the parameters are deeply influenced by adopted vibration times,among which,B(viscous,plastic,rheological and creep rate) decreases and C(creep regression coefficient) increases sharply with increasing of vibration times;with the exception of quickly destroyed specimens,both of the two parameters tend to be stable when vibration up to critical times;under the same vibration times,both of the two parameters decrease with rising of temperature,increasing of dynamic stress magnitude or chamber pressure,and are influenced little as vibration frequency higher than 6Hz.The work makes a contribution to properly predicting of settlement induced by residual deformation of frozen soil under long-term dynamic loads and provides experimental data to further research on dynamic characteristics of frozen soil.
Based on dynamic triaxial test at low temperature,deformation behavior of silty clay sampled from Beiluhe section of Qinghai-Tibet Railway under long-term cyclic loading is studied.At different negative temperatures,frequency,confining pressure and water content,relation curves between residual strain and vibration times of frozen soil are investigated;vibration excited subsidence model is built;and its parameters along with influential factors are discussed.The results demonstrate that the parameters are deeply influenced by adopted vibration times,among which,B(viscous,plastic,rheological and creep rate) decreases and C(creep regression coefficient) increases sharply with increasing of vibration times;with the exception of quickly destroyed specimens,both of the two parameters tend to be stable when vibration up to critical times;under the same vibration times,both of the two parameters decrease with rising of temperature,increasing of dynamic stress magnitude or chamber pressure,and are influenced little as vibration frequency higher than 6Hz.The work makes a contribution to properly predicting of settlement induced by residual deformation of frozen soil under long-term dynamic loads and provides experimental data to further research on dynamic characteristics of frozen soil.
引文
[1]石兆吉,郁寿松.土壤震陷参数与试验方法[J].世界地震工程,1992,(3):37-43.SHI Zhao-ji,YU Shou-song.The test method and parameter for seismic subsidence of soil[J].World Earthquake Engineering,1992,(3):37-43.
[2]THIERS G R,SEED H B.Strength and stress-strain characteristics of clays subjected to seismic loads[C]//Symposium on Vibration Effects of Earthquakes on Soils and Foundations,ASTM STP450.Philadelphia:American Society for Testing Materials,1969:3-56.
[3]LEE K L.Seismic permanent deformations in earth dams[R],Report No.UCLA-ENG-7497.California:School of Engineering and Applied Science,University of California at Los Angeles,1974.
[4]朱祖亭,周健,胡晓燕.长期动力荷载作用下饱和软黏土振陷分析[J].中国港湾建设,1998,(3):1-5.ZHU Zu-ting,ZHOU Jian,HU Xiao-yan.Analysis on dynamic settlement of a saturated soft clay under the action of a long term dynamic load[J].China Harbor Engineering,1998,(3):1-5.
[5]曹继东,陈正汉,王权民.厦门软黏土的振陷特性研究[J].岩土力学,2004,25(1):160-164.CAO Ji-dong,CHEN Zheng-han,WANG Quan-ming.study of characteristics of seismic depression of soft clay in Xiamen[J].Rock and Soil Mechanics,2004,25(1):160-164.
[6]C.C.维压洛夫,冻土流变学[M].刘建坤,刘尧军,徐艳,译.北京:中国铁道出版社,2005.
[7]VIALOV S S,GMOSHINSKII V G,GORODETSKII S E,et al.The strength and creep of frozen soils and calculations for ice-soil retaining structures[M].New Hampshire:Cold Regions Research and Engineering Laboratory,1965:76.
[8]LADANYI B.An engineering theory of creep of frozen soils[J].Canadian Geotechnical Journal,1972,9(1):63-88.
[9]TING J M.Tertiary creep model for frozen sand[J].ASCE Journal of Geotechnical Engineering,1983,109(7):932-945.
[10]王丽霞,凌贤长.冻土路基地震破坏判别方法研究[J].岩石力学与工程学报,2005,24(4):638-642.WANG Li-xia,LING Xian-zhang.Study on differentiate criteria of earthquake breakage of frozen roadbed[J].Chinese Journal of Rock Mechanics and Engineering,2005,24(4):638-642.
[11]HANS Vaziri,YINGCAI Han.Ful-scale filed studies of the dynamic response of piles embedded in partially frozen soil[J].Canadian Geotechnical Journal,1991,28:708-718.
[12]何平.饱和冻结粉土的动力特性[D].兰州:中国科学院兰州冰川冻土研究所,1992.
[13]朱元林,何平,张家懿,等.冻土在振动荷载下的三轴蠕变模型[J].自然科学进展,1998,8(1):60-62.ZHU Yuan-lin,HE Ping,ZHANG Jia-yi et al.Triaxial creep model of frozen soil under vibratory load[J].Progress in Natural Science,1998,8(1):60-62.
[14]铁道部第三勘测设计院.冻土工程[M].北京:中国铁道出版社,1994.
[15]中华人民共和国水利部.GB50123/T-99土工试验方法标准[S].北京:中国建筑工业出版社,1999.
[16]中华人民共和国机械工业部.GB50269/T-97地基动力特性测试规范[S].北京:中国建筑工业出版社,1998.
[17]徐春华,徐学燕,沈晓东.不等幅值循环荷载下冻土残余应变研究及其CT分析[J].岩土力学,2005,26(4):572-576.XU Chun-hua,XU Xue-yan,SHEN Xiao-dong.Study of residual strain of frozen soil and CT analysis under cyclic loading of variable amplitudes[J].Rock and Soil Mechanics,2005,26(4):572-576.
[18]李子春.轨道结构垂向荷载传递与路基附加动应力特性的研究[D].北京:铁道部科学研究院,2000.
[19]金鑫,沈珠江,刘崇茹.MATLAB在土工实验数据处理中的运用[J].岩土工程学报,2004,26(2):272-275.JIN Xin,SHEN Zhu-jiang,LIU Chong-ru.Date processing of geotechnical experiment using MATLAB[J].Chinese Journal of Geotechnical Engineering,2004,26(2):272-275.
[2]THIERS G R,SEED H B.Strength and stress-strain characteristics of clays subjected to seismic loads[C]//Symposium on Vibration Effects of Earthquakes on Soils and Foundations,ASTM STP450.Philadelphia:American Society for Testing Materials,1969:3-56.
[3]LEE K L.Seismic permanent deformations in earth dams[R],Report No.UCLA-ENG-7497.California:School of Engineering and Applied Science,University of California at Los Angeles,1974.
[4]朱祖亭,周健,胡晓燕.长期动力荷载作用下饱和软黏土振陷分析[J].中国港湾建设,1998,(3):1-5.ZHU Zu-ting,ZHOU Jian,HU Xiao-yan.Analysis on dynamic settlement of a saturated soft clay under the action of a long term dynamic load[J].China Harbor Engineering,1998,(3):1-5.
[5]曹继东,陈正汉,王权民.厦门软黏土的振陷特性研究[J].岩土力学,2004,25(1):160-164.CAO Ji-dong,CHEN Zheng-han,WANG Quan-ming.study of characteristics of seismic depression of soft clay in Xiamen[J].Rock and Soil Mechanics,2004,25(1):160-164.
[6]C.C.维压洛夫,冻土流变学[M].刘建坤,刘尧军,徐艳,译.北京:中国铁道出版社,2005.
[7]VIALOV S S,GMOSHINSKII V G,GORODETSKII S E,et al.The strength and creep of frozen soils and calculations for ice-soil retaining structures[M].New Hampshire:Cold Regions Research and Engineering Laboratory,1965:76.
[8]LADANYI B.An engineering theory of creep of frozen soils[J].Canadian Geotechnical Journal,1972,9(1):63-88.
[9]TING J M.Tertiary creep model for frozen sand[J].ASCE Journal of Geotechnical Engineering,1983,109(7):932-945.
[10]王丽霞,凌贤长.冻土路基地震破坏判别方法研究[J].岩石力学与工程学报,2005,24(4):638-642.WANG Li-xia,LING Xian-zhang.Study on differentiate criteria of earthquake breakage of frozen roadbed[J].Chinese Journal of Rock Mechanics and Engineering,2005,24(4):638-642.
[11]HANS Vaziri,YINGCAI Han.Ful-scale filed studies of the dynamic response of piles embedded in partially frozen soil[J].Canadian Geotechnical Journal,1991,28:708-718.
[12]何平.饱和冻结粉土的动力特性[D].兰州:中国科学院兰州冰川冻土研究所,1992.
[13]朱元林,何平,张家懿,等.冻土在振动荷载下的三轴蠕变模型[J].自然科学进展,1998,8(1):60-62.ZHU Yuan-lin,HE Ping,ZHANG Jia-yi et al.Triaxial creep model of frozen soil under vibratory load[J].Progress in Natural Science,1998,8(1):60-62.
[14]铁道部第三勘测设计院.冻土工程[M].北京:中国铁道出版社,1994.
[15]中华人民共和国水利部.GB50123/T-99土工试验方法标准[S].北京:中国建筑工业出版社,1999.
[16]中华人民共和国机械工业部.GB50269/T-97地基动力特性测试规范[S].北京:中国建筑工业出版社,1998.
[17]徐春华,徐学燕,沈晓东.不等幅值循环荷载下冻土残余应变研究及其CT分析[J].岩土力学,2005,26(4):572-576.XU Chun-hua,XU Xue-yan,SHEN Xiao-dong.Study of residual strain of frozen soil and CT analysis under cyclic loading of variable amplitudes[J].Rock and Soil Mechanics,2005,26(4):572-576.
[18]李子春.轨道结构垂向荷载传递与路基附加动应力特性的研究[D].北京:铁道部科学研究院,2000.
[19]金鑫,沈珠江,刘崇茹.MATLAB在土工实验数据处理中的运用[J].岩土工程学报,2004,26(2):272-275.JIN Xin,SHEN Zhu-jiang,LIU Chong-ru.Date processing of geotechnical experiment using MATLAB[J].Chinese Journal of Geotechnical Engineering,2004,26(2):272-275.
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