基于泊松效应抑制低液限粉土填料冻胀效果试验研究

Experimental Study on Restraining Frost Heave of Silt Filler with Low Liquid Limit Based on Poisson Effect

通过室内单向冻结试验,进行在路基中设置应力释放孔、利用泊松效应抑制低液限粉土填料冻胀效果的研究。结果表明:应力释放孔能有效地抑制土体竖向冻胀,且抑制效果随孔洞率增大而更加显著,当初始含水率为22.6%时,孔洞率为1%,2%和4%的试样对应的冻胀变形分别为3.70,2.85和1.03mm,仅为未设置应力释放孔试样冻胀变形的50.48%,38.88%和14.05%;初始含水率为20.7%时,孔洞率为1%,2%和4%的试样对应的冻胀变形分别为2.81,2.05和0.83 mm,仅为未设置应力释放孔试样冻胀变形的48.36%,35.28%和14.29%;含水率是影响冻胀的最主要因素,当试样的孔洞率一定时,初始含水率越高,土体的冻胀变形越大;设置应力释放孔对土样冻结后水分迁移的影响较小,水分迁移规律基本与未设置应力释放孔试样一致。

Through indoor unidirectional freezing tests,the effect of setting stress releasing holes in subgrade and using Poisson effect to restrain the frost heave of silt filler with low liquid limit was studied.Results show that the stress releasing holes can effectively restrain the vertical frost heave of soil,and the effect is more significant with the increase of hole ratio.When the initial moisture content is 22.6%,the corresponding frost heave deformation of the specimens with the hole ratios of 1%,2% and 4%is 3.70,2.85 and 1.03 mm respectively,which is only 50.48%,38.88% and 14.05% of the specimens without stress releasing holes.When the initial moisture content is 20.7%,the corresponding frost heave deformation of the specimens with the hole ratios of 1%,2% and 4%is 2.81,2.05 and 0.83 mm respectively,which is only 48.36%,35.28% and 14.29% of the specimens without stress releasing holes.Moisture content is the most important factor affecting frost heave.When the hole ratio of specimen is certain,the higher the initial moisture content,the greater the frost heave deformation of soil.The stress releasing hole has little effect on moisture migration after soil freezing,and the law of moisture migration is basically the same as that of the specimen without stress releasing hole.