高纬度林区软土的低温力学特性试验研究

EXPERIMENTAL STUDY ON LOW TEMPERATURE MECHANICAL PROPERTIES OF SOFT SOIL IN HIGH LATITUDE FOREST AREA

为了研究高纬度林区低温情况下软土的力学特性,以大兴安岭地区呼玛县淤泥质软土为试验对象,通过温控三轴仪进行不同负温下的不固结不排水试验,以及采用改装后的温控固结仪进行不同温度下的固结试验,试验结果表明,淤泥质软土的剪切峰值、黏聚力、摩擦角及弹性模量均随着试验温度的升高而出现下降趋势,并且在-2~-1℃之间变化最为明显;温度由负到正,淤泥质软土的固结压缩量显著增大。研究结果表明了淤泥质软土在负温条件下抗剪强度高,压缩性低,与季冻区公路工后沉降随季节变化趋势相对应,为类似工程提供参考。

Taking the muddy soft soil in Huma County in Daxing'anling area as the object,the unconsolidated and undrained experiments under different negative temperatures are carried out by temperature controlled triaxial apparatus to study the mechanical properties of soft soil under low temperature in high latitude forest area.The consolidation tests at different temperatures are also carried out by modified temperature controlled consolidation ap-paratus.The results show that the shear peak value,cohesion force,friction angle,and elastic*modulus decreased with the increase of testing temperature,which changed most obviously from -2℃to -1℃ From negative to positive temperature,the consolidation compression of mucky soft soil increases significantly.The mucky soft soil has high shear strength and low compressibility under negative temperature,which corresponds to the seasonal variation trend of highway post construction settlement in seasonal freezing area,providing a reference for similar projects.