强震作用下抗震陷黄土改良地基的微观特征分析
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摘要
基于动三轴试验和SEM细观结构测试试验,结合图像分析处理软件,对强震荷载前后宝兰客运专线沿线典型震陷性黄土及其经物理、化学和复合改良方法处理后的试样进行微观尺度的结构变形演化规律研究,探讨不同改良方法对土体微结构的影响及其与震陷系数之间的内在联系。结果表明:(1)物理改良方法对于消除大孔隙和架空孔隙结构的效果最为明显,同时对颗粒级配和结构也有调整;(2)化学改性方法则从颗粒接触方式、粒间胶结程度等方面影响土体强度,且不同化学反应的参与可生成独特的玻璃微珠或絮凝状细结构,从而大大提升土体某项参数指标,进而在强震中分别起到填充、胶结或缓冲作用;(3)强震作用前后不同改良方法对各微观要素的改变与相应的残余应变现象吻合较好,说明微结构能有效反映改良黄土残余变形的强弱。
To evaluate the relationship between micromechanisms and different physical and chemical improvement methods on the seismic subsidence loess engineering site, soil samples were obtained along the Baoji—Lanzhou High-speed Railway, and dynamic triaxial and SEM microstructural tests were conducted. Combining image processing software with the appropriate threshold, the evolution law of microstructure deformation of samples was applied and studied. Results showed that:(1) Physical improvement is the most effective way to eliminate macropores and porous pore structures; moreover, the particle size distribution and structure can be also adjusted.(2) Chemical modification affects the strength of the loess from the aspect of particle contact and intergranular cementation; moreover, the participation of different chemical reactions can produce unique glass beads or flocculent fine structures, which can greatly reinforce the strength of loess and play a role in filling, cementing, or buffering in strong earthquakes.(3) The differences between loess microcosmic parameters and residual strain coefficients, with the above improved methods before and after strong earthquakes, were compared, and it was found that they are in good agreement, indicating that the microstructure can generally reflect the residual deformation strength of the loess.
To evaluate the relationship between micromechanisms and different physical and chemical improvement methods on the seismic subsidence loess engineering site, soil samples were obtained along the Baoji—Lanzhou High-speed Railway, and dynamic triaxial and SEM microstructural tests were conducted. Combining image processing software with the appropriate threshold, the evolution law of microstructure deformation of samples was applied and studied. Results showed that:(1) Physical improvement is the most effective way to eliminate macropores and porous pore structures; moreover, the particle size distribution and structure can be also adjusted.(2) Chemical modification affects the strength of the loess from the aspect of particle contact and intergranular cementation; moreover, the participation of different chemical reactions can produce unique glass beads or flocculent fine structures, which can greatly reinforce the strength of loess and play a role in filling, cementing, or buffering in strong earthquakes.(3) The differences between loess microcosmic parameters and residual strain coefficients, with the above improved methods before and after strong earthquakes, were compared, and it was found that they are in good agreement, indicating that the microstructure can generally reflect the residual deformation strength of the loess.
引文
[1] 石玉成,李兰,刘红玫.黄土的震陷性与其微结构特征的关系研究[J].西北地震学报,2002,24(2):129-134.SHI Yucheng,LI Lan,LIU Hongmei.Study on the Relation of Loess Seismic Subsidence and Its Microstructure Characters[J].Northwestern Seismological Journal,2002,24(2):129-134.
[2] 邓津,王兰民,张振中.黄土显微结构特征与震陷性[J].岩土工程学报,2007,29(4):542-548.DENG Jin,WANG Lanmin,ZHANG Zhenzhong.Microstructure Characteristics and Seismic Subsidence of Loess[J].Chinese Journal of Geotechnical Engineering,2007,29(4):542-548.
[3] 王兰民,邓津,黄媛.黄土震陷性的微观结构量化分析[J].岩石力学与工程学报,2007,26(增刊1):3025-3031.WANG Lanmin,DENG Jin,HUANG Yuan.Quantitative Analysis of Microstructure of Loess Seismic Subsidence[J].Chinese Journal of Rock Mechanics and Engineering,2007,26(Supp1):3025-3031.
[4] 李兰,王兰民,刘旭.极震区黄土微结构的试验研究[J].中国地震,2005,21(3):369-377.LI Lan,WANG Lanmin,LIU Xu.Research on Loess Micro-structure in the Magistoseismic Area[J].Earthquake Research in China,2005,21(3):369-377.
[5] 李兰,王兰民,王峻.永登5.8级地震极震区黄土微结构孔隙性的定量研究[J].地震研究,2005,28(3):282-287.LI Lan,WANG Lanmin,WANG Jun.Quantitative Research on the Porosity of Loess in the Meizoseismal Area of the Yongdeng M5.8 Earthquake[J].Journal of Seismological Research,2005,28(3):282-287.
[6] 邓津,王兰民,吴志坚.弹塑性黄土微结构与动变形模型的建立与分析[J].岩石力学与工程学报,2013,32(增刊2):3995-4001.DENG Jin,WANG Lanmin,WU Zhijian.Establishment and Analysis of Elasto-Plastic Loess Microstructure and Dynamic Deformation Model[J].Chinese Journal of Rock Mechanics and Engineering,2013,32(Supp2):3995-4001.
[7] 石玉成,裘国荣.基于微结构的黄土震陷本构关系研究[J].岩土工程学报,2011,33(增刊1):14-18.SHI Yucheng,QIU Guorong.Constitutive Relation of Seismic Subsidence of Loess Based on Microstructure[J].Chinese Journal of Geotechnical Engineering,2011,33(Supp1):14-18.
[8] 任权,王家鼎,袁中夏,等.高速铁路地基黄土微结构的分形研究[J].水文地质工程地质,2007,34(6):76-78,82.REN Quan,WANG Jiading,YUAN Zhongxia,et al.Fractal Study on Loess Microstructure of one High-speed Railway Foundation[J].Hydrogeology and Engineering Geology,2007,34(6):76-78,82.
[9] 王强,邵生俊,王峻,等.黄土场地震陷的灾害特征及成因研究综述[J].地震研究,2016,39(4):692-702.WANG Qiang,SHAO Shengjun,WANG Jun,et al.Review on Disaster Characteristics of the Seismic Subsidence of Loess Site and Its Formation Causes[J].Journal of Seismological Research,2016,39(4):692-702.
[10] 刘园,李艳玲,杨蕾.粉煤灰改良软土路基稳定性试验研究[J].粉煤灰综合利用,2018,31(5):96-98.LIU Yuan,LI Yanling,YANG Lei.Study on the Stability Test of Improved Soft Soil Roadbed with Fly Ash[J].Fly Ash Comprehensive Utilization,2018,31(5):96-98.
[11] 许书雅,王平,王峻,等.强震作用下不同处理方式黄土地基抗震陷性能评价[J].地震工程学报,2018,40(6):1198-1205.XU Shuya,WANG Ping,WANG Jun,et al.Evaluation of Aseismic Subsidence of Loess Foundation with Different Ground Treatments under Strong Earthquake[J].China Earthquake Engineering Journal,2018,40(6):1198-1205.
[12] 王峻,高中南,车高凤,等.动荷载作用下粉煤灰改性黄土的震陷特性[J].地震工程学报,2016,38(5):751-756.WANG Jun,GAO Zhongnan,CHE Gaofeng,et al.Seismic Subsidence Behavior of Fly-ash-modified Loess under Dynamic Loading[J].China Earthquake Engineering Journal,2016,38(5):751-756.
[13] 王谦,刘红玫,马海萍,等.水泥改性黄土的抗液化特性与机制[J].岩土工程学报,2016,38(11):2128-2134.WANG Qian,LIU Hongmei,MA Haiping,et al.Liquefaction Behavior and Mechanism of Cement-stabilized Loess[J].Chinese Journal of Geotechnical Engineering,2016,38(11):2128-2134.
[14] 张克绪,凌贤长..岩土地震工程及工程振动[M].北京:科学出版社,2016.ZHANG Kexu,LING Xianchang.Geotechnical Earthquake Engineering and Engineering Vibration[M].Beijing:Science Press,2016.
[15] 张振中,张冬丽,刘红玫.黄土震陷灾害典型震例的综合研究[J].西北地震学报,2005,27(1):36-41,46.ZHANG Zhenzhong,ZHANG Dongli,LIU Hongmei.Comprehensive Study on Seismic Subsidence of Loess under Earthquake[J].Northwestern Seismological Journal,2005,27(1):36-41,46.
[2] 邓津,王兰民,张振中.黄土显微结构特征与震陷性[J].岩土工程学报,2007,29(4):542-548.DENG Jin,WANG Lanmin,ZHANG Zhenzhong.Microstructure Characteristics and Seismic Subsidence of Loess[J].Chinese Journal of Geotechnical Engineering,2007,29(4):542-548.
[3] 王兰民,邓津,黄媛.黄土震陷性的微观结构量化分析[J].岩石力学与工程学报,2007,26(增刊1):3025-3031.WANG Lanmin,DENG Jin,HUANG Yuan.Quantitative Analysis of Microstructure of Loess Seismic Subsidence[J].Chinese Journal of Rock Mechanics and Engineering,2007,26(Supp1):3025-3031.
[4] 李兰,王兰民,刘旭.极震区黄土微结构的试验研究[J].中国地震,2005,21(3):369-377.LI Lan,WANG Lanmin,LIU Xu.Research on Loess Micro-structure in the Magistoseismic Area[J].Earthquake Research in China,2005,21(3):369-377.
[5] 李兰,王兰民,王峻.永登5.8级地震极震区黄土微结构孔隙性的定量研究[J].地震研究,2005,28(3):282-287.LI Lan,WANG Lanmin,WANG Jun.Quantitative Research on the Porosity of Loess in the Meizoseismal Area of the Yongdeng M5.8 Earthquake[J].Journal of Seismological Research,2005,28(3):282-287.
[6] 邓津,王兰民,吴志坚.弹塑性黄土微结构与动变形模型的建立与分析[J].岩石力学与工程学报,2013,32(增刊2):3995-4001.DENG Jin,WANG Lanmin,WU Zhijian.Establishment and Analysis of Elasto-Plastic Loess Microstructure and Dynamic Deformation Model[J].Chinese Journal of Rock Mechanics and Engineering,2013,32(Supp2):3995-4001.
[7] 石玉成,裘国荣.基于微结构的黄土震陷本构关系研究[J].岩土工程学报,2011,33(增刊1):14-18.SHI Yucheng,QIU Guorong.Constitutive Relation of Seismic Subsidence of Loess Based on Microstructure[J].Chinese Journal of Geotechnical Engineering,2011,33(Supp1):14-18.
[8] 任权,王家鼎,袁中夏,等.高速铁路地基黄土微结构的分形研究[J].水文地质工程地质,2007,34(6):76-78,82.REN Quan,WANG Jiading,YUAN Zhongxia,et al.Fractal Study on Loess Microstructure of one High-speed Railway Foundation[J].Hydrogeology and Engineering Geology,2007,34(6):76-78,82.
[9] 王强,邵生俊,王峻,等.黄土场地震陷的灾害特征及成因研究综述[J].地震研究,2016,39(4):692-702.WANG Qiang,SHAO Shengjun,WANG Jun,et al.Review on Disaster Characteristics of the Seismic Subsidence of Loess Site and Its Formation Causes[J].Journal of Seismological Research,2016,39(4):692-702.
[10] 刘园,李艳玲,杨蕾.粉煤灰改良软土路基稳定性试验研究[J].粉煤灰综合利用,2018,31(5):96-98.LIU Yuan,LI Yanling,YANG Lei.Study on the Stability Test of Improved Soft Soil Roadbed with Fly Ash[J].Fly Ash Comprehensive Utilization,2018,31(5):96-98.
[11] 许书雅,王平,王峻,等.强震作用下不同处理方式黄土地基抗震陷性能评价[J].地震工程学报,2018,40(6):1198-1205.XU Shuya,WANG Ping,WANG Jun,et al.Evaluation of Aseismic Subsidence of Loess Foundation with Different Ground Treatments under Strong Earthquake[J].China Earthquake Engineering Journal,2018,40(6):1198-1205.
[12] 王峻,高中南,车高凤,等.动荷载作用下粉煤灰改性黄土的震陷特性[J].地震工程学报,2016,38(5):751-756.WANG Jun,GAO Zhongnan,CHE Gaofeng,et al.Seismic Subsidence Behavior of Fly-ash-modified Loess under Dynamic Loading[J].China Earthquake Engineering Journal,2016,38(5):751-756.
[13] 王谦,刘红玫,马海萍,等.水泥改性黄土的抗液化特性与机制[J].岩土工程学报,2016,38(11):2128-2134.WANG Qian,LIU Hongmei,MA Haiping,et al.Liquefaction Behavior and Mechanism of Cement-stabilized Loess[J].Chinese Journal of Geotechnical Engineering,2016,38(11):2128-2134.
[14] 张克绪,凌贤长..岩土地震工程及工程振动[M].北京:科学出版社,2016.ZHANG Kexu,LING Xianchang.Geotechnical Earthquake Engineering and Engineering Vibration[M].Beijing:Science Press,2016.
[15] 张振中,张冬丽,刘红玫.黄土震陷灾害典型震例的综合研究[J].西北地震学报,2005,27(1):36-41,46.ZHANG Zhenzhong,ZHANG Dongli,LIU Hongmei.Comprehensive Study on Seismic Subsidence of Loess under Earthquake[J].Northwestern Seismological Journal,2005,27(1):36-41,46.
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