季节冻土区保温法抑制铁路路基冻胀效果研究
摘要
模拟气候因素变化过程,得到不同时期冻土路基温度场分布,温度场随时间的变化可以反映出冻结相变区的变化;进一步分析表明,铺设保温板后,对路堤中心下冻结深度线的提升具有显著的作用,但对坡脚附近土体冻结深度线影响甚微,应当做好路基边坡防护工作。考虑土体体积力和土体冻结相变产生的膨胀力,采用热弹塑性冻胀计算模型,得到冻土路基冻胀时的变形和应力分布。在此基础之上,对冻土路基发生最大冻胀时的变形场和应力场进行分析,结果表明:利用保温法增大热阻,推迟或预防地基土的冻结,可明显减小路基冻胀隆起变形,使路基中拉应力(拉应变)减小;铺设保温板后路基坡脚附近天然地表下季节冻结层土体仍发生较大冻胀变形,其冻结时巨大的冻结膨胀力对路堤边坡仍有一定的破坏作用。建议与换填法相结合,改善坡脚附近冻胀敏感性土的土质,减弱其冻胀性,从而减小冻胀力对路堤的破坏作用。
By simulating the changing progress of climate features,the thermal regime of subgrade in seasonal frozen regions in each month is got.The variations of the thermal regime with time indicate the variations of the frost soil mass.Further analysis shows that the insulation board can obviously raise the frozen depth level below the center of the embankment with the little effect on that of the soil mass near the slope foot.So the side slope needs to be protected well.Taking into consideration the volumetric force and frozen-heave force of the soil mass and employing the thermo-elasto-plastic model,the author attained the deformation and stress distribution of the frost heave subgrade.The author analyzed the deformation and stress fields of the subgrade with the biggest frost heave deformation.Analysis results show as follows: Frost heave deformation can be obviously decreased by using the thermal-insulation method to increase thermal resistances and prevent the soil freezing,which decreases the tensile stress(tensile strain);however,the soil mass of the seasonal frozen layer under the natural ground surface near the slope foot is seen in large frost heave deformation and the huge expansion force generated in freezing causes damage to the side slope;the soil-replacing method is suggested to be adopted together with the thermal-insulation method to improve the soil with frost heave sensitive near the slope foot,reduce the frost heave ratio and lessen the damage of the frozen-heave force to the embankment.
By simulating the changing progress of climate features,the thermal regime of subgrade in seasonal frozen regions in each month is got.The variations of the thermal regime with time indicate the variations of the frost soil mass.Further analysis shows that the insulation board can obviously raise the frozen depth level below the center of the embankment with the little effect on that of the soil mass near the slope foot.So the side slope needs to be protected well.Taking into consideration the volumetric force and frozen-heave force of the soil mass and employing the thermo-elasto-plastic model,the author attained the deformation and stress distribution of the frost heave subgrade.The author analyzed the deformation and stress fields of the subgrade with the biggest frost heave deformation.Analysis results show as follows: Frost heave deformation can be obviously decreased by using the thermal-insulation method to increase thermal resistances and prevent the soil freezing,which decreases the tensile stress(tensile strain);however,the soil mass of the seasonal frozen layer under the natural ground surface near the slope foot is seen in large frost heave deformation and the huge expansion force generated in freezing causes damage to the side slope;the soil-replacing method is suggested to be adopted together with the thermal-insulation method to improve the soil with frost heave sensitive near the slope foot,reduce the frost heave ratio and lessen the damage of the frozen-heave force to the embankment.
引文
[1]HAYHOE H N,BALCHIN D.Field Frost Heave Meas-urement and Prediction during Periods of Seasonal Frost[J].Canadian Geotechnical Journal,1990,27(3):393-397.
[2]曹东伟,胡长顺.多年冻土区路基融沉变形的附加应力分析[J].重庆交通学院学报,2001,20(3):57-61.CAO Dong-wei,HU Chang-shun.Analysis for AdditionalStress in Pavement due to Thawing Settlement of Perma-frost Subgrade[J].Journal of Chongqing Jiaotong Univer-sity,2001,20(3):57-61.
[3]温智,盛煜,马巍,等.多年冻土区铁路保温路基变形特征研究[J].岩石力学与工程学报,2007,26(8):1670-1677.WEN Zhi,SHENG Yu,MA Wei,et al.Study on Deform-ation Character of Railway Insulated Embankment in Per-mafrost Regions[J].Chinese Journal of Rock Mechanicsand Engineering,2007,26(8):1670-1677.
[4]戴惠民,乐鹏飞,王兴隆.季冻区公路路基土冻胀性的研究[J].中国公路学报,1994,7(2):1-8.DAI Hui-min,LE Peng-fei,WANG Xing-long.FrostHeave Susceptibility of Highway Subgrade Soils in Season-al Frost Regions[J].China Journal of Highway and Trans-port,1994,7(2):1-8.
[5]童长江,管枫年.土的冻胀与建筑物冻害防治[M].北京:水利电力出版社,1985.
[6]Clarke E S,Krzewinski T G,Metz M C.The Trans Alas-ka Pipeline System Synthetically Insulated Workpad:AnEvaluation of Present Conditions[C]//Proceedings of theASME Energy Resources Technology Conference and Ex-hibition in Houston.Texas:ASME,1981.
[7]Metz M C,Krzewinski T G,Clarke E S.The Trans Alas-ka Pipeline System Workpad:An Evaluation of PresentConditions[C]//Proceedings of the 4th Canadian Perma-frost Conference.Ottawa:National Research Council ofCanada,1982.
[8]Lauren A Larsen M,Thomas G Krzewinski M,Jay BBergman M.Use of Rigid Insulation below Grade forRoadways and Parking Areas[C]//Proceedings of the 6thInternational Specialty Conference.New York:ASCE,1991:428-437.
[9]胡宇.EPS保温板在青藏高原多年冻土区路基工程中的应用研究[D].成都:西南交通大学,2003:39-52.
[10]LAI Yuan-ming,WANG Qiu-sheng,NIU Fu-jun.Three-Dimensional Nonlinear Analysis for Temperature Charac-teristic of Ventilated Embankment in Permafrost Regions[J].Cold Regions Science and Technology,2004,38(2/3):165-184.
[11]铁道第一勘查设计院.沈哈客运专线D3K690+700～D3K693+000地基处理及路堤坡面防护工程地质勘察报告[R].西安,铁道第一勘查设计院,2006.
[12]朱林楠.高原冻土区不同下垫面的附面层研究[J].冰川冻土,1988,10(1):8-14.ZHU Lin-nan.Study of the Adherent Layer on DifferentTypes of Ground in Permafrost Regions on the Qinghai-Tibet Plateau[J].Journal of Glaciology and Geocryology,1988,10(1):8-14.
[13]王钧.中国地温分布的基本特征[M].北京:地震出版社,1990.
[14]徐学组,陶兆祥,傅素兰.典型融冻土的热学性质[M]//中国科学院兰州冰川冻土沙漠研究所.中国科学院兰州冰川冻土沙漠所集刊(第2号).北京:科学出版社,1981:104-112.
[15]Sheppard M T,Kay B D,Loch J P G.Development andTesting of a Computer Model for Heat and Mass Flow inFreezing Soils[C]//Proceeding of the 3rd InternationalConference on Permafrost.Ottawa:National ResearchCouncil of Canada,1978:76-81.
[16]吴紫汪,马巍.冻土强度与蠕变[M].兰州:兰州大学出版社,1994.
[2]曹东伟,胡长顺.多年冻土区路基融沉变形的附加应力分析[J].重庆交通学院学报,2001,20(3):57-61.CAO Dong-wei,HU Chang-shun.Analysis for AdditionalStress in Pavement due to Thawing Settlement of Perma-frost Subgrade[J].Journal of Chongqing Jiaotong Univer-sity,2001,20(3):57-61.
[3]温智,盛煜,马巍,等.多年冻土区铁路保温路基变形特征研究[J].岩石力学与工程学报,2007,26(8):1670-1677.WEN Zhi,SHENG Yu,MA Wei,et al.Study on Deform-ation Character of Railway Insulated Embankment in Per-mafrost Regions[J].Chinese Journal of Rock Mechanicsand Engineering,2007,26(8):1670-1677.
[4]戴惠民,乐鹏飞,王兴隆.季冻区公路路基土冻胀性的研究[J].中国公路学报,1994,7(2):1-8.DAI Hui-min,LE Peng-fei,WANG Xing-long.FrostHeave Susceptibility of Highway Subgrade Soils in Season-al Frost Regions[J].China Journal of Highway and Trans-port,1994,7(2):1-8.
[5]童长江,管枫年.土的冻胀与建筑物冻害防治[M].北京:水利电力出版社,1985.
[6]Clarke E S,Krzewinski T G,Metz M C.The Trans Alas-ka Pipeline System Synthetically Insulated Workpad:AnEvaluation of Present Conditions[C]//Proceedings of theASME Energy Resources Technology Conference and Ex-hibition in Houston.Texas:ASME,1981.
[7]Metz M C,Krzewinski T G,Clarke E S.The Trans Alas-ka Pipeline System Workpad:An Evaluation of PresentConditions[C]//Proceedings of the 4th Canadian Perma-frost Conference.Ottawa:National Research Council ofCanada,1982.
[8]Lauren A Larsen M,Thomas G Krzewinski M,Jay BBergman M.Use of Rigid Insulation below Grade forRoadways and Parking Areas[C]//Proceedings of the 6thInternational Specialty Conference.New York:ASCE,1991:428-437.
[9]胡宇.EPS保温板在青藏高原多年冻土区路基工程中的应用研究[D].成都:西南交通大学,2003:39-52.
[10]LAI Yuan-ming,WANG Qiu-sheng,NIU Fu-jun.Three-Dimensional Nonlinear Analysis for Temperature Charac-teristic of Ventilated Embankment in Permafrost Regions[J].Cold Regions Science and Technology,2004,38(2/3):165-184.
[11]铁道第一勘查设计院.沈哈客运专线D3K690+700～D3K693+000地基处理及路堤坡面防护工程地质勘察报告[R].西安,铁道第一勘查设计院,2006.
[12]朱林楠.高原冻土区不同下垫面的附面层研究[J].冰川冻土,1988,10(1):8-14.ZHU Lin-nan.Study of the Adherent Layer on DifferentTypes of Ground in Permafrost Regions on the Qinghai-Tibet Plateau[J].Journal of Glaciology and Geocryology,1988,10(1):8-14.
[13]王钧.中国地温分布的基本特征[M].北京:地震出版社,1990.
[14]徐学组,陶兆祥,傅素兰.典型融冻土的热学性质[M]//中国科学院兰州冰川冻土沙漠研究所.中国科学院兰州冰川冻土沙漠所集刊(第2号).北京:科学出版社,1981:104-112.
[15]Sheppard M T,Kay B D,Loch J P G.Development andTesting of a Computer Model for Heat and Mass Flow inFreezing Soils[C]//Proceeding of the 3rd InternationalConference on Permafrost.Ottawa:National ResearchCouncil of Canada,1978:76-81.
[16]吴紫汪,马巍.冻土强度与蠕变[M].兰州:兰州大学出版社,1994.
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