黏性土剪切带的形成与其屈服的内在联系的探索

Study on internal relations between formation of shear bands and its yield in clay

为了深入了解黏性土的应力应变特性,对黏性土进行了量测侧向变形的不排水平面应变压缩试验。分析试验结果发现,黏性土局部化变形的起始点与黏性土样中的孔隙水压力的突然增长的转折点非常接近,而孔隙水压力开始急剧增长变化的转折点为其屈服点,说明黏性土剪切带开始形成的偏应力为其屈服点,超过此点后黏性土局部化变形加剧,这个发现将有助于土体在强度理论、变形和稳定分析等方面的深入研究。

In order to find a thorough stress-strain characteristic in clay, a series of consolidation undrained plane strain compression experiments were made. Local lateral non-homogeneous deformation in the samples were recorded. Through analysis for the experimental results, it is found that characteristic values of localized deformation began to form are very close to suddenly increased turning point of the pore water pressure, But the suddenly increased turning point of the pore water pressure is its yield point in clay soil. It is shown that the deviator stress of shear band began to form is very close to its yield point in clay soil. Exceeding this point, the localized deformation speeds up. The discovery will conduce to a thorough study on strength theory, deformation and stability analysis in soil.