冻融循环对土体强度变形参数的影响

Effects of freeze-thaw cycles on soil strength and deformation parameters

在寒区工程建设中,冻融循环会引起土强度和变形特性发生改变。为了研究多次冻融循环后土的强度和变形参数的变化量,本文以冻融和非冻融的粉质粘土饱和试样为研究对象,通过固结排水三轴剪切试验、三轴等向压缩试验和弹性模量试验,比较了冻融循环对土样强度参数和变形参数的影响。试验结果显示:冻融和非冻融试样的应力应变关系曲线均呈应变硬化型,对于原状试样冻融作用破坏了其结构性;冻融作用导致土体强度的降低,主要体现在粘聚力的降低,约降低了55.6%;冻融循环对变形参数有明显的影响,其中最明显的是弹性模量的降低,降低了31.2%。该研究结论可为工程冻害处理提供参考,也可为相关研究的数值计算提供试验参数。

The change of soil strength and deformation parameters caused by the freeze-thaw cycle is one of the important issues with engineering works in the cold area.In order to investigate the change of strength and deformation parameters,with the saturated silty clay samples taken after and before the freeze-thaw cycle as the research object,the triaxial shear test after consolidation and drainage,triaxial isotropic compression test and elastic modulus test were carried out to analyze the effects of freeze-thaw cycles on soil strength and deformation parameters.The research results can be used as reference for the treatment of frost damage in engineering works and also as testing data for numerical simulation.