碎石土湿陷性试验研究
|
摘要
采用不同工况的载荷试验、室内常规土工试验和易溶盐试验,分析了碎石土的荷载-沉降曲线特征,探讨了碎石土的湿陷性与湿陷机理。结果表明:碎石土在200 kPa稳定后浸水,再加荷到400 kPa,载荷试验荷载-沉降曲线呈折线型,明显分为三个阶段:压缩变形阶段,湿陷变形阶段,复合变形阶段。场地中4 m厚碎石土具有湿陷性,且湿陷性不均匀。碎石土湿陷的机理在于其结构是疏松的单粒架空结构。骨架颗粒间存在架空孔隙,且部分架空孔隙由砂质颗粒集合体充填;骨架颗粒间呈点与点接触,或者主要通过黏粒、黏土矿物、易溶盐组成的胶结物而联结在一起;在浸水加荷过程中,黏粒周围薄膜水增厚、粘土矿物自身产生膨胀、易溶盐溶解,导致胶结物的胶结强度丧失,结构失稳,发生湿陷。
The characteristics of load–settlement curve of gravel soil and the collapsibility and collapsible mechanism of gravel soil were studied based on the results from plate loading tests under different work conditions,routine soil tests and soluble salt tests.The study shows that when the gravel soil stabilized under the load of 200 kPa,then immersed in the water and loaded to 400 kPa,the load-settlement curve is a broken curve,and can be obviously divided into three phases: compressive deformation phase,collapsible deformation phase and composite deformation phase.The gravel soil with 4m thick has collapsiblity and its collapsibility is uneven.The collapsible mechanism of gravel soil is due to its loose single-grain open structure.There is open pore in the frame grains and some of open pore is filled with sandy grain aggregation;frame grains are linked together with point-to-point contact or mainly connected with cement consisting of clay particle,clay minerals and soluble salt.During the process of ponding and loading,the film water around clay partvicle is becoming thicker,the clay minerals expands itself and soluble salt dissolves,so as to lead the loss of the cement strength and destabilization of the structure;and thus the gravel soil collapses.
The characteristics of load–settlement curve of gravel soil and the collapsibility and collapsible mechanism of gravel soil were studied based on the results from plate loading tests under different work conditions,routine soil tests and soluble salt tests.The study shows that when the gravel soil stabilized under the load of 200 kPa,then immersed in the water and loaded to 400 kPa,the load-settlement curve is a broken curve,and can be obviously divided into three phases: compressive deformation phase,collapsible deformation phase and composite deformation phase.The gravel soil with 4m thick has collapsiblity and its collapsibility is uneven.The collapsible mechanism of gravel soil is due to its loose single-grain open structure.There is open pore in the frame grains and some of open pore is filled with sandy grain aggregation;frame grains are linked together with point-to-point contact or mainly connected with cement consisting of clay particle,clay minerals and soluble salt.During the process of ponding and loading,the film water around clay partvicle is becoming thicker,the clay minerals expands itself and soluble salt dissolves,so as to lead the loss of the cement strength and destabilization of the structure;and thus the gravel soil collapses.
引文
[1]陕西省计划委员会主编.GB50025-2004湿陷性黄土地区建筑规范[S].北京:中国建筑工业出版社,2004.
[2]钱鸿缙,王继唐,罗宇生,等.湿陷性黄土地基[M].北京:中国建筑工业出版社,1985.
[3]钱家欢,殷宗泽.土工原理与计算[M].北京:中国水利水电出版社,1996.
[4]中华人民共和国国家标准编写组.GB50021-2001岩土工程勘察规范[S].北京:中国建筑工业出版社,2002.
[5]王生新,韩文峰,谌文武,等.冲击压实路基黄土的微观特征研究[J].岩土力学,2006,27(6):939-944.WANG Sheng-xin,HAN Wen-feng,CHEN Wen-wu,et al.Microstudy on roadbed loess improvement by impact compaction technology[J].Rock and Soil Mechanics,2006,27(6):939-944.
[6]王生新.硅化黄土的机理与时效性研究[博士学位论文D].兰州:兰州大学,2005.
[7]尹亚雄,王生新,韩文峰,等.加气硅化黄土的微结构研究[J].岩土力学,2008,29(6):1629-1633.YIN Ya-xiong,WANG Sheng-xin,HAN Wen-feng,et al.Study on microstructure of co2-silicification grouted loess[J].Rock and Soil Mechanics,2008,29(6):1629-1633.
[8]李保雄,牛永红,苗天德.兰州马兰黄土的物理力学特性[J].岩土力学,2007,28(6):1077-1082.LI Bao-xiong,NIU Yong-hong,MIAO Tian-de.Physico-mechanical characteristics of Malan loess in Lanzhou region[J].Rock and Soil Mechanics,2007,28(6):1077-1082.
[9]刘恩龙,沈珠江,范文.结构性粘土研究进展[J].岩土力学,2005,26(增刊):1-8.LIU En-long,SHEN Zhu-jiang,FAN Wen.Advance in researches on structured clay[J].Rock and Soil Mechanics,2005,26(Supp.):1-8.
[10]胡瑞林,王思敬,李向全,等.模拟强夯下黄土的固结变形特征及其微观分析[J].岩土力学,1999,20(4):12-18.HU Rui-ling,WANG Shi-jin,LI Xiang-quan,et al.Consolidation deformation characteristics of loess under the simulated dynamic compaction and the microstructural analysis[J].Rock and Soil Mechanics,1999,20(4):12-18.
[11]王吉利,刘怡林,沈兴付,等.冲击碾压法处理黄土地基的试验研究[J].岩土力学,2005,(5):755-758.WANG Ji-li,LIU Yi-lin,SHEN Xing-fu,et al.Experimental investigation on treatment of loess subgrade with impaction and grind method(IGM)[J].Rock and Soil Mechanics,2005,(5):755-758.
[12]杨运来.黄土湿陷机理的研究[J].中国科学(B辑),1988,(7):756-766.YANG Yun-lai.Study of the mechanism of loess collapse[J].Science in China(Series B),1988,(7):756-766.
[13]高国瑞.中国黄土的微结构[J].科学通报,1980,(24):945-948.GAO Guo-rui.Micro-structure of loess soils in China[J].China Science Bulletin,1980,(24):945-948.
[14]雷祥义.中国黄土的孔隙类型与湿陷性[J].中国科学(B辑),1987,(12):1 309-1 315.LEI Xiang-yi.Pore types and collapsibility of loess soils in China[J].Science in China(Series B),1987,(12):1 309-1315.
[15]谢定义.试论我国黄土力学研究中的若干新趋向[J].岩土工程学报,2001,23(1):1-13.XIE Ding-yi.Exploration of some new tendencies in research of loess soil mechanics[J].Chinese Journal of Geotechnical Engineering,2001,23(1):1-13.
[16]骆亚生,张爱军.黄土结构性的研究成果及其新发展[J].水力发电学报,2004,23(6):66-69.LUO Ya-sheng,ZHANG Ai-jun.Outcomes on structural research of loess and its newadvance[J].Journal of Hydroelectric Engineering,2004,23(6):66-69.
[17]沈珠江.土体结构性的数学模型—21世纪土力学的核心问题[J].岩土工程学报,1996,18(1):95-97.SHEN Zhu-jiang.Mathematical model of soil mass structure—core problems of soil mechanics in 21st century[J].Chinese Journal of Geotechnical Engineering,1996,18(1):95-97.
[18]齐吉琳,谢定义,石玉成.土结构性的研究方法及现状[J].西北地震学报,2001,23(1):99-103.QI Ji-lin,XIE Ding-yi,SHI Yu-cheng.Status quo and method of quantitative study on soil structure[J].Northwestern Seismological Journal,2001,23(1):99-103.
[19]贾剑.风成砂土湿陷性研究[J].电力勘测设计,1997,14(2):18-21.Jia Jian.Study on the collapsibility of the eollan sand[J].Electric power survey&design,1997,14(2):18-21.
[20]曾正中,张明泉,黄明源.腾格里沙漠南缘风积砂土湿陷性研究[J].甘肃科学学报,2000,12(2):63-68.ZENG Zheng-zhong,ZHANG Ming-quan,HUANG Ming-yuan.A study on the collapsibility of the eollan sand on the south edge of the Tenggeli desert[J].Journal of Gansu Sciences,2000,12(2):63-68.
[21]刘文平,时卫民,孔位学,等.水对三峡库区碎石土的弱化作用[J].岩土力学,2005,26(11):1857-1861.LIU Wen-ping,SHI Wei-min,KONG Wei-xue,et al.Weakening effect of water on gravel-soil in Three Gorges Reservoir area[J].Rock and Soil Mechanics,2005,26(11):1857-1861.
[22]李维树,吴相超,乐俊义,等.原位载荷试验在优化土质地基基础设计中的作用[J].岩土力学,2003,24(增1):24-27.LI Wei-shu,WU Xiang-chao,YUE Jun-yi,et al.Application of in-situ loading tests to optimizing design for subgrade soils[J].Rock and Soil Mechanics,2003,24(supp.1):24-27.
[2]钱鸿缙,王继唐,罗宇生,等.湿陷性黄土地基[M].北京:中国建筑工业出版社,1985.
[3]钱家欢,殷宗泽.土工原理与计算[M].北京:中国水利水电出版社,1996.
[4]中华人民共和国国家标准编写组.GB50021-2001岩土工程勘察规范[S].北京:中国建筑工业出版社,2002.
[5]王生新,韩文峰,谌文武,等.冲击压实路基黄土的微观特征研究[J].岩土力学,2006,27(6):939-944.WANG Sheng-xin,HAN Wen-feng,CHEN Wen-wu,et al.Microstudy on roadbed loess improvement by impact compaction technology[J].Rock and Soil Mechanics,2006,27(6):939-944.
[6]王生新.硅化黄土的机理与时效性研究[博士学位论文D].兰州:兰州大学,2005.
[7]尹亚雄,王生新,韩文峰,等.加气硅化黄土的微结构研究[J].岩土力学,2008,29(6):1629-1633.YIN Ya-xiong,WANG Sheng-xin,HAN Wen-feng,et al.Study on microstructure of co2-silicification grouted loess[J].Rock and Soil Mechanics,2008,29(6):1629-1633.
[8]李保雄,牛永红,苗天德.兰州马兰黄土的物理力学特性[J].岩土力学,2007,28(6):1077-1082.LI Bao-xiong,NIU Yong-hong,MIAO Tian-de.Physico-mechanical characteristics of Malan loess in Lanzhou region[J].Rock and Soil Mechanics,2007,28(6):1077-1082.
[9]刘恩龙,沈珠江,范文.结构性粘土研究进展[J].岩土力学,2005,26(增刊):1-8.LIU En-long,SHEN Zhu-jiang,FAN Wen.Advance in researches on structured clay[J].Rock and Soil Mechanics,2005,26(Supp.):1-8.
[10]胡瑞林,王思敬,李向全,等.模拟强夯下黄土的固结变形特征及其微观分析[J].岩土力学,1999,20(4):12-18.HU Rui-ling,WANG Shi-jin,LI Xiang-quan,et al.Consolidation deformation characteristics of loess under the simulated dynamic compaction and the microstructural analysis[J].Rock and Soil Mechanics,1999,20(4):12-18.
[11]王吉利,刘怡林,沈兴付,等.冲击碾压法处理黄土地基的试验研究[J].岩土力学,2005,(5):755-758.WANG Ji-li,LIU Yi-lin,SHEN Xing-fu,et al.Experimental investigation on treatment of loess subgrade with impaction and grind method(IGM)[J].Rock and Soil Mechanics,2005,(5):755-758.
[12]杨运来.黄土湿陷机理的研究[J].中国科学(B辑),1988,(7):756-766.YANG Yun-lai.Study of the mechanism of loess collapse[J].Science in China(Series B),1988,(7):756-766.
[13]高国瑞.中国黄土的微结构[J].科学通报,1980,(24):945-948.GAO Guo-rui.Micro-structure of loess soils in China[J].China Science Bulletin,1980,(24):945-948.
[14]雷祥义.中国黄土的孔隙类型与湿陷性[J].中国科学(B辑),1987,(12):1 309-1 315.LEI Xiang-yi.Pore types and collapsibility of loess soils in China[J].Science in China(Series B),1987,(12):1 309-1315.
[15]谢定义.试论我国黄土力学研究中的若干新趋向[J].岩土工程学报,2001,23(1):1-13.XIE Ding-yi.Exploration of some new tendencies in research of loess soil mechanics[J].Chinese Journal of Geotechnical Engineering,2001,23(1):1-13.
[16]骆亚生,张爱军.黄土结构性的研究成果及其新发展[J].水力发电学报,2004,23(6):66-69.LUO Ya-sheng,ZHANG Ai-jun.Outcomes on structural research of loess and its newadvance[J].Journal of Hydroelectric Engineering,2004,23(6):66-69.
[17]沈珠江.土体结构性的数学模型—21世纪土力学的核心问题[J].岩土工程学报,1996,18(1):95-97.SHEN Zhu-jiang.Mathematical model of soil mass structure—core problems of soil mechanics in 21st century[J].Chinese Journal of Geotechnical Engineering,1996,18(1):95-97.
[18]齐吉琳,谢定义,石玉成.土结构性的研究方法及现状[J].西北地震学报,2001,23(1):99-103.QI Ji-lin,XIE Ding-yi,SHI Yu-cheng.Status quo and method of quantitative study on soil structure[J].Northwestern Seismological Journal,2001,23(1):99-103.
[19]贾剑.风成砂土湿陷性研究[J].电力勘测设计,1997,14(2):18-21.Jia Jian.Study on the collapsibility of the eollan sand[J].Electric power survey&design,1997,14(2):18-21.
[20]曾正中,张明泉,黄明源.腾格里沙漠南缘风积砂土湿陷性研究[J].甘肃科学学报,2000,12(2):63-68.ZENG Zheng-zhong,ZHANG Ming-quan,HUANG Ming-yuan.A study on the collapsibility of the eollan sand on the south edge of the Tenggeli desert[J].Journal of Gansu Sciences,2000,12(2):63-68.
[21]刘文平,时卫民,孔位学,等.水对三峡库区碎石土的弱化作用[J].岩土力学,2005,26(11):1857-1861.LIU Wen-ping,SHI Wei-min,KONG Wei-xue,et al.Weakening effect of water on gravel-soil in Three Gorges Reservoir area[J].Rock and Soil Mechanics,2005,26(11):1857-1861.
[22]李维树,吴相超,乐俊义,等.原位载荷试验在优化土质地基基础设计中的作用[J].岩土力学,2003,24(增1):24-27.LI Wei-shu,WU Xiang-chao,YUE Jun-yi,et al.Application of in-situ loading tests to optimizing design for subgrade soils[J].Rock and Soil Mechanics,2003,24(supp.1):24-27.
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心