基于透明黏土的取土器贯入扰动变形试验研究

为了解取土器贯入过程中黏土体的扰动变形特性,采用由Aristoflex AVC制成的新型透明黏土及粒子图像测速(PIV)技术,通过可视化模型试验装置进行了不同尺寸的取土器贯入试验。试验结果表明:取土器贯入过程中各截面不同位置处的土体变形规律基本一致,距离管壁越远,变形越小；取土器下部土体整体性较好,且距离中轴线约0.19倍取土器内径范围内的土体剪应变较小,室内试验可切取这部分土体；取土器贯入引起的土体扰动变形主要由侧壁摩阻力及刃脚挤土效应引起,增大取土器内径能有效减小取土器内土体的压缩变形。

Experimental study on disturbance deformation of soil sampler penetration based on transparent clay

In order to understand the disturbance and deformation characteristics of clay during the penetration of soil sampler, the novel transparent clay made by Aristoflex AVC and the particle image velocimetry (PIV) technique were used to carry out the penetration tests of soil sampler with different sizes through the visual model test device. The test results show that the deformation distribution characteristics of soil in different sections are nearly the same, and the deformation decreases as it distances away from the tube wall. The soil at the lower part of the sampler has good integrity, and the shear strain of the soil within about 0.19 times the core diameter from the central axis of sampler is small, which is suitable for doing the laboratory experiment. Sampler penetration disturbance is mainly caused by the frictional resistance of the sidewall and the squeezing effect of edged foot, so increasing the inner diameter of soil sampler can effectively reduce the compressive deformation of soil in the sampler.