低应力水平下土遗址力学特性的干湿循环效应
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摘要
为分析干湿循环对土遗址力学性状的影响规律及作用机制,以遗址粉土为研究对象,采用自制的可分层取样试验装置开展长达15个月的干湿循环测试工作。在完成一定次数的干湿循环后,分别取样进行低应力条件下三轴排水剪切试验,并对部分土样进行相关微观试验。三轴排水剪切试验结果表明,与初始土样相比,1次干湿循环土样的应变软化特征显著增强,但随着干湿循环次数的继续增加,其应变软化性整体上呈减弱趋势;同时,黏聚力c、变形模量E0也都呈现出1次循环后明显增大随后逐渐减小的变化规律。因此,在土遗址浅层破坏修复工程中,建议采用干湿循环稳定后低应力水平下的力学参数进行相关计算。结合压汞试验结果,认为造成上述土体强度及变形参数随干湿循环次数非单调变化的主要原因是,第1次干湿循环后土样团粒内孔隙体积减小,而循环后期团粒内、颗粒间及颗粒内孔隙体积增大。同时,遗址粉土力学特性的干湿循环效应主要受粉土中黏粒"三维网架"的均匀收缩和局部破坏所控制,与黏土的干湿循环作用机制存在本质差异。研究可为土遗址预防性保护及加固提供技术依据和理论支撑。
In order to analyze the influence law and mechanism of dry-wet circulation on the mechanical properties of earthen archaeological site,the dry-wet circulation test was carried out by using the self-made stratified sampling test device. The test lasted as long as 15 months. The samples which were prepared for microscopic test and triaxial drainage shear test under low stress conditions were from the soil column after a certain number of dry and wet cycles. Triaxial drainage shear test results show that the strain softening characteristics are enhanced significantly when the soil experiences the first dry-wet circulation. As the number of dry-wet cycles continues to increase,the strain softening decreases gradually on the whole. The cohesion c and deformation modulus E0 also increase significantly after one cycle,and then gradually decrease. The strength and deformation parameters of soil show the law of nonmonotonic change under the action of dry-wet circulation. It was suggested that mechanical parameters of dry-wet circulation after stabilization under low stress level should be used for the shallow damage restoration project in earthen archaeological sites. Combined with the mercury injection test results,It was concluded that the main reason of the nonmonotonic change law is that the volume of intra-aggregate pore decreases after one cycle and then the volumes of intra-aggregate,intragranular pores and intergranular pores increase at the later stage of circulation. The dry-wet circulation effect of silt mechanical properties may be mainly controlled by the uniform shrinkage and local failure of clay "three-dimensional grid structure" in silt,which is essentially different from that of clay. The research can provide technical basis and theoretical support for the preventive protection and reinforcement of earthen archaeological site.
In order to analyze the influence law and mechanism of dry-wet circulation on the mechanical properties of earthen archaeological site,the dry-wet circulation test was carried out by using the self-made stratified sampling test device. The test lasted as long as 15 months. The samples which were prepared for microscopic test and triaxial drainage shear test under low stress conditions were from the soil column after a certain number of dry and wet cycles. Triaxial drainage shear test results show that the strain softening characteristics are enhanced significantly when the soil experiences the first dry-wet circulation. As the number of dry-wet cycles continues to increase,the strain softening decreases gradually on the whole. The cohesion c and deformation modulus E0 also increase significantly after one cycle,and then gradually decrease. The strength and deformation parameters of soil show the law of nonmonotonic change under the action of dry-wet circulation. It was suggested that mechanical parameters of dry-wet circulation after stabilization under low stress level should be used for the shallow damage restoration project in earthen archaeological sites. Combined with the mercury injection test results,It was concluded that the main reason of the nonmonotonic change law is that the volume of intra-aggregate pore decreases after one cycle and then the volumes of intra-aggregate,intragranular pores and intergranular pores increase at the later stage of circulation. The dry-wet circulation effect of silt mechanical properties may be mainly controlled by the uniform shrinkage and local failure of clay "three-dimensional grid structure" in silt,which is essentially different from that of clay. The research can provide technical basis and theoretical support for the preventive protection and reinforcement of earthen archaeological site.
引文
[1]孙满利.土遗址保护研究现状与进展[J].文物保护与考古科学,2007,19(4):64-70.(SUN Manli.Research status and development of the conservation of earthen sites[J].Sciences of Conservation and Archaeology,2007,19(4):64-70.(in Chinese))
[2]陈爱兰.河南省文物志[M].北京:文物出版社,2009:123-177.(CHEN Ailan.Henan provincial cultural relics[M].Beijing:Cultural Relics Press,2009:123-177.(in Chinese))
[3]崔凯,谌文武,匡静,等.干湿交替与盐渍双重作用干旱和半干旱地区土遗址劣化效应[J].中南大学学报:自然科学版,2012,43(6):361-367.(CUI Kai,CHEN Wenwu,KUANG Jing,et al.Effect of deterioration of earthern ruin with joint function of salinized and alternating wet and dry in arid and semi-arid regions[J].Journal of Central South University:Science and Technology,2012,43(6):361-367.(in Chinese))
[4]张景科,谌文武,和法国,等.高陡濒倾土遗址边坡加固后的变形行为[J].文物保护与考古科学,2012,24(1):56-61.(ZHANGJingke,CHEN Wenwu,HE Faguo,et al.Deformation of crumbling high steep earthen slope of cultural heritage after conservation[J].Sciences of Conservation and Archaeology,2012,24(1):56-61.(in Chinese))
[5]IRAVANIAN A,BILSEL H.Tensile strength properties of sand-bentonite mixtures enhanced with cement[C]//Procedia Engineering.[S.l.]:[s.n.],2016:111-118.
[6]孙满利,王旭东,李最雄,等.交河故城的裂隙特征研究[J].岩土工程学报,2007,29(4):612-617.(SUN Manli,WANG Xudong,LI Zuixiong,et al.Study on cranny characteristics of the ruins of Jiaohe[J].Chinese Journal of Geotechnical Engineering,2007,29(4):612-617.(in Chinese))
[7]ALLAM M M,SRIDHARAN A.Effect of wetting and drying on shear strength[J].Journal of the Geotechnical Engineering Division,1981,107(4):421-438.
[8]GUAN G S,RAHARDJO H,CHOON L E.Shear strength equations for unsaturated soil under drying and wetting[J].Journal of Geotechnical and Geoenvironmental Engineering,2010,136(4):594-606.
[9]孙文静,韦广,崔玉军,等.粉土干化过程中微观结构的演变[J].岩石力学与工程学报,2017,36(10):2 544-2 550.(SUN Wenjing,WEI Guang,CUI Yujun,et al.Microstructure evolution in silty soil during drying[J].Chinese Journal of Rock Mechanics and Engineering,2017,36(10):2 544-2 550.(in Chinese))
[10]张涛,乐金朝,张俊然.干湿循环对豫东粉土路基强度的影响及其预测[J].公路,2016,(4):200-206.(ZHANG Tao,YUEJinchao,ZHANG Junran.Influence of dry and wet cycle on roadbed strength and its prediction[J].Highway,2016,(4):200-206.(in Chinese))
[11]张虎元,严耿升,赵天宇,等.土建筑遗址干湿耐久性研究[J].岩土力学,2011,32(2):347-355.(ZHANG Huyuan,YAN Gengsheng,ZHAO Tianyu,et al.Durability of earthen architecture ruins under cyclic wetting and drying[J].Rock and Soil Mechanics,2011,32(2):347-355.(in Chinese))
[12]孟庆明,彭兴黔,梁兰娣.福建土楼夯土试块在干湿循环的抗压强度试验研究[J].青岛理工大学学报,2015,36(1):41-45.(MENGQingming,PENG Xingqian,LIANG Landi.Experimental study of Fujian tulou rammed earth blocks on compressive strength in drying and wetting cysles[J]Journal of Qingdao Technological University,2015,36(1):41-45.(in Chinese))
[13]黄强兵,刘悦,彭建兵.黄土路堑边坡变形破坏机制的三轴试验研究[J].工程地质学报,2007,15(6):806-811.(HUANGQiangbing,LIU Yue,PENG Jianbing.Triaxial test study on the deformation and failure mechanism of loess cut slope[J].Journal of Engineering Geology,2007,15(6):806-811.(in Chinese))
[14]肖杰,杨和平,李晗峰,等.膨胀土边坡浅层破坏稳定性分析[J].交通运输工程学报,2014,14(2):21-27.(XIAO Jie,YANG Heping,LI Hanfeng,et al.Shear strength test of Nanning expansive soil with various dry densities and low stresses[J].China Journal of Highway and Transport,2014,14(2):21-27.(in Chinese))
[15]连继峰,罗强,蒋良潍,等.雨水浸润软化下路基土质边坡浅层稳定分析[J].铁道学报,2017,39(4):101-108.(LIAN Jifeng,LUOQiang,JIANG Liangwei,et al.Stability analysis of shallow soil slope under effect of rainfall infiltration[J].Journal of The China Railway Society,2017,39(4):101-108.(in Chinese))
[16]陈毅,张虎元,杨龙.遗址土劣化进程中微观结构变化的类比研究[J].岩土力学,2018,39(11):1-9.(CHEN Yi,ZHANG Huyuan,YANG Long.Analogy study on evolution of microstructure of earthen monument during natural weathering process[J].Rock and Soil Mechanics,2018,39(11):1-9.(in Chinese))
[17]胡再强,于淼,李宏儒,等.人工制备遗址土力学特性试验研究[J].岩石力学与工程学报,2016,35(9):1 914-1 923.(HUZaiqiang,YU Miao,LI Hongru,et al.Experimental study on characteristics of artificial soil ruins[J].Chinese Journal of Rock Mechanics and Engineering,2016,35(9):1 914-1 923.(in Chinese))
[18]MAKSIMOVIC M.Nonlinear failure envelope for soils[J].Journal of Geotechnical Engineering,1989,115(4):581-586.
[19]GRIFFITHS F J,JOSHI R C.Changes in pore size distribution due to consolidation of clays[J].Geotechnique,1989,39:159-167.
[20]张先伟,孔令伟,郭爱国,等.基于SEM和MIP试验结构性黏土压缩过程中微观孔隙的变化规律[J].岩石力学与工程学报,2012,31(2):406-412.(ZHANG Xianwei,KONG Lingwei,GUO Aiguo,et al.Evolution of microscopic pore of structured clay in compression process based on SEM and MIP test[J].Chinese Journal of Rock Mechanics and Engineering,2012,31(2):406-412.(in Chinese))
[21]NOWAMOOZ H,JAHANGIR E,MASROURI F,et al.Effective stress in swelling soils during wetting drying cycles[J].Engineering Geology,2016,210:33-44.
[22]KAY B D,DEXTER A R.The influence of dispersible clay and wetting/drying cycles on the tensile strength of a red-brown earth[J].Soil Research,1992,30(3):297-310.
[23]ALDAOOD A,BOUASKER M,AL-MUKHTAR M.Impact of wetting-drying cycles on the microstructure and mechanical properties of lime-stabilized gypseous soils[J].Engineering Geology,2014,174(1):11-21.
[24]尹松,孔令伟,张先伟.炎热多雨气候影响下残积土小应变刚度特性试验研究[J].岩土工程学报,2017,39(4):743-751.(YINSong,KONG Lingwei1,ZHANG Xianwei.Experimental study on stiffness characteristics of residual soil at small strain under hot and rainy climate[J].Chinese Journal of Geotechnical Engineering,2017,39(4):743-751.(in Chinese))
[25]吴燕锋,巴特尔·巴克,阿斯姑力·托合提,等.1958~2012年郑州市极端气温和极端气温事件年际变化特征[J].中国农学通报,2014,30(23):259-265.(WU Yanfeng,Bater·Baker,Asiguli·Tuoheti,et al.The variation of extreme temperature and extreme weather events from 1958 to 2012 in Zhengzhou[J].Chinese Agricultural Science Bulletin,2014,30(23):259-265.(in Chinese))
[26]刘文化.干湿循环对非饱和土力学特性影响及非饱和土本构关系探讨[博士学位论文][D].大连:大连理工大学,2015.(LIU Wenhua.Effect of drying/wetting on the mechanical behaviors of unsaturated soils and study on the constitutive relationship of unsaturated soils[Ph.D.Thesis][D].Dalian:Dalian University of Technology,2015.(in Chinese))
[27]江强强,刘路路,焦玉勇,等.干湿循环下滑带土强度特性与微观结构[J].岩土力学,2019,待刊.(JIANG Qiangqiang,LIU Lulu,JIAOYuyong,et al.Strength properties and microstructure characteristics of slip zone soil under wetting-drying cycles[J].Rock and Soil Mechanics,2019,(to be Pressed).(in Chinese))
[28]SHEAR D L,OLSEN H W,NELSON K R.Effects of desiccation on the hydraulic conductivity versus void ratio relationship for a natural clay[R].Washington D C:National Academy Press,1993:1 365-1 370.
[29]程允,韦昌富,牛庚.干湿循环作用对岩溶区红黏土剪切强度的影响[J].岩土力学,2017,38(增2):191-196.(CHENG Yun,WEI Chanfu,NIU Geng.Effect of wetting and drying cycles on shear strength of karst red clay[J].Rock and Soil Mechanics,2017,38(Supp.2):191-196.(in Chinese))
[30]万勇,薛强,吴彦,等.干湿循环作用下压实黏土力学特性与微观机制研究[J].岩土力学,2015,36(10):2 815-2 824.(WANYong,XUE Qiang,WU Yan,et al.Mechanical properties and micromechanisms of compacted clay during drying-wetting cycles[J].Rock and Soil Mechanics,2015,36(10):2 815-2 824.(in Chinese))
[2]陈爱兰.河南省文物志[M].北京:文物出版社,2009:123-177.(CHEN Ailan.Henan provincial cultural relics[M].Beijing:Cultural Relics Press,2009:123-177.(in Chinese))
[3]崔凯,谌文武,匡静,等.干湿交替与盐渍双重作用干旱和半干旱地区土遗址劣化效应[J].中南大学学报:自然科学版,2012,43(6):361-367.(CUI Kai,CHEN Wenwu,KUANG Jing,et al.Effect of deterioration of earthern ruin with joint function of salinized and alternating wet and dry in arid and semi-arid regions[J].Journal of Central South University:Science and Technology,2012,43(6):361-367.(in Chinese))
[4]张景科,谌文武,和法国,等.高陡濒倾土遗址边坡加固后的变形行为[J].文物保护与考古科学,2012,24(1):56-61.(ZHANGJingke,CHEN Wenwu,HE Faguo,et al.Deformation of crumbling high steep earthen slope of cultural heritage after conservation[J].Sciences of Conservation and Archaeology,2012,24(1):56-61.(in Chinese))
[5]IRAVANIAN A,BILSEL H.Tensile strength properties of sand-bentonite mixtures enhanced with cement[C]//Procedia Engineering.[S.l.]:[s.n.],2016:111-118.
[6]孙满利,王旭东,李最雄,等.交河故城的裂隙特征研究[J].岩土工程学报,2007,29(4):612-617.(SUN Manli,WANG Xudong,LI Zuixiong,et al.Study on cranny characteristics of the ruins of Jiaohe[J].Chinese Journal of Geotechnical Engineering,2007,29(4):612-617.(in Chinese))
[7]ALLAM M M,SRIDHARAN A.Effect of wetting and drying on shear strength[J].Journal of the Geotechnical Engineering Division,1981,107(4):421-438.
[8]GUAN G S,RAHARDJO H,CHOON L E.Shear strength equations for unsaturated soil under drying and wetting[J].Journal of Geotechnical and Geoenvironmental Engineering,2010,136(4):594-606.
[9]孙文静,韦广,崔玉军,等.粉土干化过程中微观结构的演变[J].岩石力学与工程学报,2017,36(10):2 544-2 550.(SUN Wenjing,WEI Guang,CUI Yujun,et al.Microstructure evolution in silty soil during drying[J].Chinese Journal of Rock Mechanics and Engineering,2017,36(10):2 544-2 550.(in Chinese))
[10]张涛,乐金朝,张俊然.干湿循环对豫东粉土路基强度的影响及其预测[J].公路,2016,(4):200-206.(ZHANG Tao,YUEJinchao,ZHANG Junran.Influence of dry and wet cycle on roadbed strength and its prediction[J].Highway,2016,(4):200-206.(in Chinese))
[11]张虎元,严耿升,赵天宇,等.土建筑遗址干湿耐久性研究[J].岩土力学,2011,32(2):347-355.(ZHANG Huyuan,YAN Gengsheng,ZHAO Tianyu,et al.Durability of earthen architecture ruins under cyclic wetting and drying[J].Rock and Soil Mechanics,2011,32(2):347-355.(in Chinese))
[12]孟庆明,彭兴黔,梁兰娣.福建土楼夯土试块在干湿循环的抗压强度试验研究[J].青岛理工大学学报,2015,36(1):41-45.(MENGQingming,PENG Xingqian,LIANG Landi.Experimental study of Fujian tulou rammed earth blocks on compressive strength in drying and wetting cysles[J]Journal of Qingdao Technological University,2015,36(1):41-45.(in Chinese))
[13]黄强兵,刘悦,彭建兵.黄土路堑边坡变形破坏机制的三轴试验研究[J].工程地质学报,2007,15(6):806-811.(HUANGQiangbing,LIU Yue,PENG Jianbing.Triaxial test study on the deformation and failure mechanism of loess cut slope[J].Journal of Engineering Geology,2007,15(6):806-811.(in Chinese))
[14]肖杰,杨和平,李晗峰,等.膨胀土边坡浅层破坏稳定性分析[J].交通运输工程学报,2014,14(2):21-27.(XIAO Jie,YANG Heping,LI Hanfeng,et al.Shear strength test of Nanning expansive soil with various dry densities and low stresses[J].China Journal of Highway and Transport,2014,14(2):21-27.(in Chinese))
[15]连继峰,罗强,蒋良潍,等.雨水浸润软化下路基土质边坡浅层稳定分析[J].铁道学报,2017,39(4):101-108.(LIAN Jifeng,LUOQiang,JIANG Liangwei,et al.Stability analysis of shallow soil slope under effect of rainfall infiltration[J].Journal of The China Railway Society,2017,39(4):101-108.(in Chinese))
[16]陈毅,张虎元,杨龙.遗址土劣化进程中微观结构变化的类比研究[J].岩土力学,2018,39(11):1-9.(CHEN Yi,ZHANG Huyuan,YANG Long.Analogy study on evolution of microstructure of earthen monument during natural weathering process[J].Rock and Soil Mechanics,2018,39(11):1-9.(in Chinese))
[17]胡再强,于淼,李宏儒,等.人工制备遗址土力学特性试验研究[J].岩石力学与工程学报,2016,35(9):1 914-1 923.(HUZaiqiang,YU Miao,LI Hongru,et al.Experimental study on characteristics of artificial soil ruins[J].Chinese Journal of Rock Mechanics and Engineering,2016,35(9):1 914-1 923.(in Chinese))
[18]MAKSIMOVIC M.Nonlinear failure envelope for soils[J].Journal of Geotechnical Engineering,1989,115(4):581-586.
[19]GRIFFITHS F J,JOSHI R C.Changes in pore size distribution due to consolidation of clays[J].Geotechnique,1989,39:159-167.
[20]张先伟,孔令伟,郭爱国,等.基于SEM和MIP试验结构性黏土压缩过程中微观孔隙的变化规律[J].岩石力学与工程学报,2012,31(2):406-412.(ZHANG Xianwei,KONG Lingwei,GUO Aiguo,et al.Evolution of microscopic pore of structured clay in compression process based on SEM and MIP test[J].Chinese Journal of Rock Mechanics and Engineering,2012,31(2):406-412.(in Chinese))
[21]NOWAMOOZ H,JAHANGIR E,MASROURI F,et al.Effective stress in swelling soils during wetting drying cycles[J].Engineering Geology,2016,210:33-44.
[22]KAY B D,DEXTER A R.The influence of dispersible clay and wetting/drying cycles on the tensile strength of a red-brown earth[J].Soil Research,1992,30(3):297-310.
[23]ALDAOOD A,BOUASKER M,AL-MUKHTAR M.Impact of wetting-drying cycles on the microstructure and mechanical properties of lime-stabilized gypseous soils[J].Engineering Geology,2014,174(1):11-21.
[24]尹松,孔令伟,张先伟.炎热多雨气候影响下残积土小应变刚度特性试验研究[J].岩土工程学报,2017,39(4):743-751.(YINSong,KONG Lingwei1,ZHANG Xianwei.Experimental study on stiffness characteristics of residual soil at small strain under hot and rainy climate[J].Chinese Journal of Geotechnical Engineering,2017,39(4):743-751.(in Chinese))
[25]吴燕锋,巴特尔·巴克,阿斯姑力·托合提,等.1958~2012年郑州市极端气温和极端气温事件年际变化特征[J].中国农学通报,2014,30(23):259-265.(WU Yanfeng,Bater·Baker,Asiguli·Tuoheti,et al.The variation of extreme temperature and extreme weather events from 1958 to 2012 in Zhengzhou[J].Chinese Agricultural Science Bulletin,2014,30(23):259-265.(in Chinese))
[26]刘文化.干湿循环对非饱和土力学特性影响及非饱和土本构关系探讨[博士学位论文][D].大连:大连理工大学,2015.(LIU Wenhua.Effect of drying/wetting on the mechanical behaviors of unsaturated soils and study on the constitutive relationship of unsaturated soils[Ph.D.Thesis][D].Dalian:Dalian University of Technology,2015.(in Chinese))
[27]江强强,刘路路,焦玉勇,等.干湿循环下滑带土强度特性与微观结构[J].岩土力学,2019,待刊.(JIANG Qiangqiang,LIU Lulu,JIAOYuyong,et al.Strength properties and microstructure characteristics of slip zone soil under wetting-drying cycles[J].Rock and Soil Mechanics,2019,(to be Pressed).(in Chinese))
[28]SHEAR D L,OLSEN H W,NELSON K R.Effects of desiccation on the hydraulic conductivity versus void ratio relationship for a natural clay[R].Washington D C:National Academy Press,1993:1 365-1 370.
[29]程允,韦昌富,牛庚.干湿循环作用对岩溶区红黏土剪切强度的影响[J].岩土力学,2017,38(增2):191-196.(CHENG Yun,WEI Chanfu,NIU Geng.Effect of wetting and drying cycles on shear strength of karst red clay[J].Rock and Soil Mechanics,2017,38(Supp.2):191-196.(in Chinese))
[30]万勇,薛强,吴彦,等.干湿循环作用下压实黏土力学特性与微观机制研究[J].岩土力学,2015,36(10):2 815-2 824.(WANYong,XUE Qiang,WU Yan,et al.Mechanical properties and micromechanisms of compacted clay during drying-wetting cycles[J].Rock and Soil Mechanics,2015,36(10):2 815-2 824.(in Chinese))
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