不排水强度随固结度增长特性试验研究

Experimental research of undrained strength with the increasing of consolidation degree

土体的固结程度对土的强度影响很大,采用等应变速率的直剪仪研究了饱和高岭土在各级固结压力作用下的直剪强度随固结度的变化规律,研究表明:各级固结压力下的直剪强度均随固结度的增长呈近似线性增长。利用微型十字板剪切仪研究了各级固结压力作用下的微型十字板强度随固结度的变化规律,同时考虑到尺寸效应的影响,研制了配合微型十字板剪切仪使用的小直径固结仪,研究表明:微型十字板强度同样随固结度的增长而呈线性增长;将以上两种试验结果进行比较分析,发现具有很好的一致性,验证了用微型十字板剪切仪来研究饱和软粘土抗剪强度变化规律是可行的。

Degree of consolidation of soil has a great influence on the strength of the soil.Direct shear apparatu with constant strain rate is applied to investigate direct shear strength change law with the increase of consolidation degree by saturated kaolin at all levels of consolidation pressure.Results show that direct shear strength increases linearly with the increase of degree of consolidation at all levels of consolidation pressure.Then,miniature vane shear apparatus is performed to study the micro vane strength changing rules.At the same time,considering the size effect,a small diameter consolidation apparatus cooperated with miniature vane shear apparatus is developed.Studies show that miniature vane shear strength grows linearly with the increase of consolidation degrees.Comparing the above two kinds of test results,it is found that they have good consistency.It confirms that miniature vane shear apparatus studying the shear strength change law of saturated soft clay is feasible.