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INFLUENCES OF TEMPERATURE AMPLITUDES AND TIME INTERVALS ON FROST HEAVE
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摘要: 选取冻胀敏感性粉质黏土，利用人工冻土一维冻胀试验系统进行不同变温幅度和间歇时间作用下的后间歇冻结试验，以试样冻深达到稳定阶段为初始时刻分析冻结锋面、冻胀量及温度梯度变化曲线，得到冷端变温幅度和间歇时间对土体冻胀的影响规律。结果表明：不同变温幅度作用下的冻结锋面、冻胀量曲线呈周期性变化，变化周期为240 min，与间歇时间相同。随着变温幅度的增大，冻胀量分别为3.38，2.55 mm，与连续冻结模式相比，冻胀量分别减少了23.2%，42.0%。相同变温幅度，间歇时间为2，4，8 h的土体冻胀量曲线分别呈抛物型、阶梯型和折线型增长趋势，冻胀量分别为2.82，2.55和1.81 mm。土体冻胀量随着间歇时间的增大而减小，但间歇时间不宜大于8 h，否则分凝冰层融化，冻胀量衰减，对于实际冻结工程，则会影响冻土壁强度。Abstract: In this paper,frost heave tests using frost susceptible silty clay were carried out by 1-D frost heaving test system with different temperature amplitudes and time intervals in continuous-intermittent freezing mode.Freezing front,frost heave and temperature gradient were analyzed when frost depth reached in stable stage.The influences of temperature amplitudes and time intervals on frost heave were acquaired.The results show that,in different temperature amplitudes,the curves of freezing front and frost heave fluctuate periodically and the period is 240 min which is equal to time intervals.Frost heave is 3.38 mm and 2.55 mm in different temperature amplitudes.With the increase of temperature amplitudes,frost heave reduce 23.2% and 42.0% respectively than that in continuous freezing mode.In different time intervals,frost heave increase in the parabolic,step and broken line type.Frost heave is 2.82 mm,2.55 mm and 1.81 mm when time intervals are 2 h,4 h and 8 h respectively.It is clear that frost heave reduces with the increase of time intervals.However,if time intervals are longer than 8 h,segregation ice and frost heave decrease.In that case,the strength of frozen wall will decrease in artificial freezing project.
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[2] 周晓敏,苏立凡,贺长俊,等.北京地铁隧道水平冻结法施工[J].岩土工程学报,1999,21(35):319－322. 陈瑞杰,程国栋,李述训,等.人工地层冻结应用研究进展和展望[J].岩土工程学报,2000,22(1):40－44. [3] 王文顺,王建平,井绪文,等.人工冻结过程中温度场的试验研究[J].中国矿业大学学报,2004,33(4):388－391. [4] 童长江,管枫年.土的冻胀与建筑物冻害的防治[M].北京:水利电力出版社,1985:1. [5] 王建平.人工冻土冻胀融沉规律的研究[D].徐州:中国矿业大学,1999. [6] Everest D H.The Thermodynamics of Frost Damage to PorousSolids[J].Trans.Faraday Soc.,1961,57:1541－1551. [7] Miller R D.Freezing and Heaving of Saturated and UnsaturatedSoils[J].Highway Research Record,1972(393):1－11. [8] Miller R D.Lens Initiation in Secondary Frost Heaving[C]∥Int.Symp.on Frost Action in Soils,1977. [9] Harlan R L.Analysis of Coupled Heat-Fluid Transport in PartiallyFrozen Soil[J].Water Resources Research,1973,9(5):1314－1323. [10] ONell K,Miller R D.Exploration of a Rigid-Ice Model of FrostHeave[J].Water Resources Research,1985,21:281－296. [11] Konrad J M,Morgenstern N R.The Segregation Potential of aFreezing Soil[J].Canadian Geotechnical Journal,1981,18:482－491. [12] Konrad J M,Morgenstern N R.A Mechanistic Theory of Ice LensFormation in Fine-Grained Soils[J].Canadian GeotechnicalJournal,1980,17:473－486. [13] Nixon J F.Discrete Ice Lens Theory for Frost Heave in Soils[J].Canadian Geotechnical Journal,1991,28:843－859. [14] 曹宏章,刘石,姜凡,等.饱和颗粒土一维冰分凝模型及数值模拟[J].力学学报,2007,39(6):848－857. [15] 周扬,周国庆,周金生,等.饱和土冻结透镜体生长过程水热耦合分析[J].岩土工程学报,2010,32(4):578－585. [16] 周国庆.间歇冻结抑制人工冻土冻胀机理分析[J].中国矿业大学学报,1999,28(5):413－416. [17] 商翔宇.冻土冻胀与冻结模式关系的试验与数值模拟研究[D].徐州:中国矿业大学,2004. [18] 周金生,周国庆,马魏,等.间歇冻结控制人工冻土冻胀的试验研究[J].中国矿业大学学报,2006,35(6):708－712. [19] 胡坤,周国庆,张琦,等.不同间歇冻结模式土体冻胀控制试验研究[J].西安建筑科技大学学报,2010,42(2):278－282. -
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