冻融循环作用下宽级配砾质土的渗透特性
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摘要
针对西北地区特殊的气候条件和砾质土料源丰富的实际情况,提出采用宽级配砾质土代替黏土作为土工合成材料膨润土垫(GCls)的保护层共同构成垃圾填埋场复合防渗系统的构想。文中选取宁夏银川地区冲-洪积作用形成的天然砾质土料,经人工掺和制配成满足规范对GCls防渗垫保护层渗透系数要求的宽级配砾质土样,在实验室对该土样进行了冻融循环作用下的渗透性能试验研究。结果显示,随着冻融次数的逐渐增加,土样的冻胀率逐渐变大,渗透系数也相应增大,经过12次冻融循环后,渗透系数约增大1~2个数量级;冻融循环初期,冻融作用对土样的影响最为剧烈,随着冻融循环次数的增加以及时间的延续,土样性状逐渐趋于稳定。由于宽级配砾质土对冻融循环作用的敏感性小于粉质黏性土,故采用宽级配砾质土作为Cls/GM的保护层共同组成填埋场复合防渗系统是值得期待的。
The design conception of composite liners is consisted of a geomembrane( GM),geosynthetic clay liners( GCls) and compacted gravel soils in landfills. This conception is presented on the basis of the climate characteristics,gravel soils material rich in nature,and GCls that have been exported all over the world for various applications. The artificially graded gravel soils are taken from natural sediment zone for flood alluvial at Yinchuan suburb in Ningxia. The gravel soil is figured out to meet the requirement of permeability coefficient through the compaction and penetration experiment. The frost-heaving ratio and hydraulic conductivity of gravel soil samples are tested under freeze-thaw cycling in this paper. The test results indicate that the frost-heaving ratio increases as the number of freeze-thaw increases. As the number of freeze-thaw increases,the permeability coefficient also increases.The permeability coefficient is increased by one to two orders of magnitude after 12 cycles of freezing-thawing. At the beginning of freeze-thaw cycle,it has an influence on the soil samples. The influence tends to be relatively stable state as the number of freeze-thaw cycles increases. The sensitivity of gravel soils under freeze-thaw cycling is less than that of the silt clay. It is acceptable to undertake the landfill composite liners which will be comprised of GCls / GM and compacted gravel soils together.
The design conception of composite liners is consisted of a geomembrane( GM),geosynthetic clay liners( GCls) and compacted gravel soils in landfills. This conception is presented on the basis of the climate characteristics,gravel soils material rich in nature,and GCls that have been exported all over the world for various applications. The artificially graded gravel soils are taken from natural sediment zone for flood alluvial at Yinchuan suburb in Ningxia. The gravel soil is figured out to meet the requirement of permeability coefficient through the compaction and penetration experiment. The frost-heaving ratio and hydraulic conductivity of gravel soil samples are tested under freeze-thaw cycling in this paper. The test results indicate that the frost-heaving ratio increases as the number of freeze-thaw increases. As the number of freeze-thaw increases,the permeability coefficient also increases.The permeability coefficient is increased by one to two orders of magnitude after 12 cycles of freezing-thawing. At the beginning of freeze-thaw cycle,it has an influence on the soil samples. The influence tends to be relatively stable state as the number of freeze-thaw cycles increases. The sensitivity of gravel soils under freeze-thaw cycling is less than that of the silt clay. It is acceptable to undertake the landfill composite liners which will be comprised of GCls / GM and compacted gravel soils together.
引文
Anderson R,Rayhani M T,Rowe R K.2012.Laboratory investigation ofGCL hydration from clayey sand subsoil[J].Geotextiles andGeomembranes,31:31~38.
Barroso M,Touze-Foltz N,von Maubeuge K,et al.2006.Laboratoryinvestigation of flow rate through composite liners consisting of ageomembrane,a GCL and a soil liner[J].Geotextiles andGeomembranes,24(3):139~155.
Bouazza A.2002.Geosynthetic clay liners[J].Geotextiles andGeomembranes,20(1):3~17.
Bradshaw S L,Benson C H,Scalia V J.2013.Hydration and cationexchange during subgrade hydration and effect on hydraulicconductivity of geosynthetic clay liners[J].Journal of Geotechnicaland Geoenvironmental Engineering,139(4):526~538.
He J,Wan J,Wang Y.2012.Desiccation cracks and hydraulicperformance of compacted clay liner via laboratory wet-dry cyclingtests[J].Journal of Engineering Geology,20(3):397~402.
Hewitt R D,Daniel D E.1997.Hydraulic conductivity of geosyntheticclay liners after freeze-thaw[J].Journal of Geotechnical andGeoenvironmental Engineering,123(4):305~313.
Huang W R,Guo Z P.2000.Experimental research on preventingdesiccation cracking of compacted clay liner in municipal solid wastelandfill[J].Journal of Hohai University(Natural Sciences),28(6):19~22.
Joseph Scalia IV S M,Benson C H.2011.Hydraulic conductivity ofgeosynthetic clay liners exhumed from landfill final covers withcomposite barriers[J].Journal of Geotechnical andGeoenvironmental Engineering,137(1):1~13.
Kim W H,Daniel D E.1992.Effects of freezing on hydraulic conductivityof compacted clay[J].Journal of Geotechnical Engineering,118(7):1083~1097.
Koerner R M,Narejo D.1995.Bearing capacity of hydrated geosyntheticclay liners[J].Journal of Geotechnical Engineering,121(1):82~85.
Koerner R M.2000.Emerging and future developments of selectedgeosynthetic applications[J].Journal of Geotechnical andGeoenvironmental Engineering,126(4):291~306.
Kraus J E,Benson C H,Chamberlain E J.1997.Freeze-thaw cycling andhydraulic conductivity of bentonitic barriers[J].Journal ofGeotechnical and Geoenvironmental Engineering,123(3):229~238.
Lian J B,Zhang A J,Guo M X,et al.2010.Influence of iterativefreezing-thawing on void ratio and permeability coefficient ofloess[J].Yangtze River,41(12):55~58.
Liu C L,Zhang Y,Wang X Y,et al.2000.A lining system of wastelandfilling site adequate for current situation in China[J].Journal ofEngineering Geology,8(1):118~122.
Peng W W.1988.Experimental study of frost susceptibility of sandygravel with different contents of fine-grained soil[J].Journal ofGlaciology and Geocryology,10(1):22~27.
Qi J L,Zhang J M,Zhu Y L.2003.Influence of freezing-thawing on soilstructure and its soil mechanics significance[J].Chinese Journal ofRock Mechanics and Engineering,22(S2):2690~2694.
Rayhani M T,Rowe R K,Brachman R W I,et al.2011.Factors affectingGCL hydration under isothermal conditions[J].Geotextiles andGeomembranes,29(6):525~533.
Rowe R K,Mukunoki T,Bathurst R J,et al.2007.Performance of ageocomposite liner for containing Jet A-1 spill in an extremeenvironment[J].Geotextiles and Geomembranes,25(2):68~77.
Rowe R K,Orsini C.2003.Effect of GCL and subgrade type on internalerosion in GCls[J].Geotextiles and Geo-membranes,21(1):1~24.
The Professional Standards Complilation Group of People's Republic ofChina.2007.Technical code for liner system of municipau solidwaste landfill[S].Beijing:China Architecture&Building Press.
Wang H Y,Zhang X K,Yang Y W.2010.A study of the feasibility ofgravel soils material as a protector of the GCls/GM barrier[J].Hydrogeology and Engineering Geology,37(5):102~107.
Xiong X B,Shi B,Zhang L.2000.The recent development ofgeotechnical research on municipal waste sanitary landfill in foreigncountries[J].Journal of Engineering Geology,8(3):345~350.
Yang C S,He P,Cheng G D,et al.2003.Testing study on influence offreezing and thawing on dry density and water content of soil[J].Chinese Journal of Rock Mechanics and Engineering,22(S2):2695~2699.
何俊,万娟,王宇.2012.压实黏土干燥裂隙及渗透性能研究[J].工程地质学报,20(3):397~402.
黄婉荣,郭志平.2000.填埋场压实黏土衬垫防干裂试验研究[J].河海大学学报,28(6):19~22.
连江波,张爱军,郭敏霞,等.2010.反复冻融循环对黄土孔隙比及渗透性的影响[J].人民长江,41(12):55~58.
刘长礼,张云,王秀艳,等.2000.适合国情的垃圾填埋场衬垫系统[J].工程地质学报,8(1):118~122.
彭万巍.1988.不同掺合料砂砾石的冻胀实验研究[J].冰川冻土,10(1):22~27.
齐吉琳,张建明,朱元林.2003.冻融作用对土结构性影响的土力学意义[J].岩石力学与工程学报,22(增2):2690~2694.
王红雨,张学科,杨燕伟.2010.宽级配砾石土作为GCls/GM防渗垫保护层的可行性研究[J].水文地质工程地质,37(5):102~107.
熊孝波,施斌,张凌.2000.国外城市垃圾填埋场岩土工程研究的最新进展[J].工程地质学报,8(3):345~350.
杨成松,何平,成国栋,等.2003.冻融作用对土体干容重和含水量影响的试验研究[J].岩石力学与工程学报,22(增2):2695~2699.
中华人民共和国行业标准编写组.2007.生活垃圾卫生填埋场防渗系统工程技术规范(CJJ113—2007)[S].北京:中国建筑工业出版社.
Barroso M,Touze-Foltz N,von Maubeuge K,et al.2006.Laboratoryinvestigation of flow rate through composite liners consisting of ageomembrane,a GCL and a soil liner[J].Geotextiles andGeomembranes,24(3):139~155.
Bouazza A.2002.Geosynthetic clay liners[J].Geotextiles andGeomembranes,20(1):3~17.
Bradshaw S L,Benson C H,Scalia V J.2013.Hydration and cationexchange during subgrade hydration and effect on hydraulicconductivity of geosynthetic clay liners[J].Journal of Geotechnicaland Geoenvironmental Engineering,139(4):526~538.
He J,Wan J,Wang Y.2012.Desiccation cracks and hydraulicperformance of compacted clay liner via laboratory wet-dry cyclingtests[J].Journal of Engineering Geology,20(3):397~402.
Hewitt R D,Daniel D E.1997.Hydraulic conductivity of geosyntheticclay liners after freeze-thaw[J].Journal of Geotechnical andGeoenvironmental Engineering,123(4):305~313.
Huang W R,Guo Z P.2000.Experimental research on preventingdesiccation cracking of compacted clay liner in municipal solid wastelandfill[J].Journal of Hohai University(Natural Sciences),28(6):19~22.
Joseph Scalia IV S M,Benson C H.2011.Hydraulic conductivity ofgeosynthetic clay liners exhumed from landfill final covers withcomposite barriers[J].Journal of Geotechnical andGeoenvironmental Engineering,137(1):1~13.
Kim W H,Daniel D E.1992.Effects of freezing on hydraulic conductivityof compacted clay[J].Journal of Geotechnical Engineering,118(7):1083~1097.
Koerner R M,Narejo D.1995.Bearing capacity of hydrated geosyntheticclay liners[J].Journal of Geotechnical Engineering,121(1):82~85.
Koerner R M.2000.Emerging and future developments of selectedgeosynthetic applications[J].Journal of Geotechnical andGeoenvironmental Engineering,126(4):291~306.
Kraus J E,Benson C H,Chamberlain E J.1997.Freeze-thaw cycling andhydraulic conductivity of bentonitic barriers[J].Journal ofGeotechnical and Geoenvironmental Engineering,123(3):229~238.
Lian J B,Zhang A J,Guo M X,et al.2010.Influence of iterativefreezing-thawing on void ratio and permeability coefficient ofloess[J].Yangtze River,41(12):55~58.
Liu C L,Zhang Y,Wang X Y,et al.2000.A lining system of wastelandfilling site adequate for current situation in China[J].Journal ofEngineering Geology,8(1):118~122.
Peng W W.1988.Experimental study of frost susceptibility of sandygravel with different contents of fine-grained soil[J].Journal ofGlaciology and Geocryology,10(1):22~27.
Qi J L,Zhang J M,Zhu Y L.2003.Influence of freezing-thawing on soilstructure and its soil mechanics significance[J].Chinese Journal ofRock Mechanics and Engineering,22(S2):2690~2694.
Rayhani M T,Rowe R K,Brachman R W I,et al.2011.Factors affectingGCL hydration under isothermal conditions[J].Geotextiles andGeomembranes,29(6):525~533.
Rowe R K,Mukunoki T,Bathurst R J,et al.2007.Performance of ageocomposite liner for containing Jet A-1 spill in an extremeenvironment[J].Geotextiles and Geomembranes,25(2):68~77.
Rowe R K,Orsini C.2003.Effect of GCL and subgrade type on internalerosion in GCls[J].Geotextiles and Geo-membranes,21(1):1~24.
The Professional Standards Complilation Group of People's Republic ofChina.2007.Technical code for liner system of municipau solidwaste landfill[S].Beijing:China Architecture&Building Press.
Wang H Y,Zhang X K,Yang Y W.2010.A study of the feasibility ofgravel soils material as a protector of the GCls/GM barrier[J].Hydrogeology and Engineering Geology,37(5):102~107.
Xiong X B,Shi B,Zhang L.2000.The recent development ofgeotechnical research on municipal waste sanitary landfill in foreigncountries[J].Journal of Engineering Geology,8(3):345~350.
Yang C S,He P,Cheng G D,et al.2003.Testing study on influence offreezing and thawing on dry density and water content of soil[J].Chinese Journal of Rock Mechanics and Engineering,22(S2):2695~2699.
何俊,万娟,王宇.2012.压实黏土干燥裂隙及渗透性能研究[J].工程地质学报,20(3):397~402.
黄婉荣,郭志平.2000.填埋场压实黏土衬垫防干裂试验研究[J].河海大学学报,28(6):19~22.
连江波,张爱军,郭敏霞,等.2010.反复冻融循环对黄土孔隙比及渗透性的影响[J].人民长江,41(12):55~58.
刘长礼,张云,王秀艳,等.2000.适合国情的垃圾填埋场衬垫系统[J].工程地质学报,8(1):118~122.
彭万巍.1988.不同掺合料砂砾石的冻胀实验研究[J].冰川冻土,10(1):22~27.
齐吉琳,张建明,朱元林.2003.冻融作用对土结构性影响的土力学意义[J].岩石力学与工程学报,22(增2):2690~2694.
王红雨,张学科,杨燕伟.2010.宽级配砾石土作为GCls/GM防渗垫保护层的可行性研究[J].水文地质工程地质,37(5):102~107.
熊孝波,施斌,张凌.2000.国外城市垃圾填埋场岩土工程研究的最新进展[J].工程地质学报,8(3):345~350.
杨成松,何平,成国栋,等.2003.冻融作用对土体干容重和含水量影响的试验研究[J].岩石力学与工程学报,22(增2):2695~2699.
中华人民共和国行业标准编写组.2007.生活垃圾卫生填埋场防渗系统工程技术规范(CJJ113—2007)[S].北京:中国建筑工业出版社.