土体真三轴仪的边界效应试验

为了研究刚性、半刚性、柔性3种边界对试验结果的影响,使用河海大学TSW-40型真三轴仪对粗粒土试样进行保持水平向应力不变、竖直向应力增加的单向加荷试验。结果表明:对高宽比为1∶1的立方体试样,刚性边界对试样的约束作用很明显;在试样顶部使用竖向刚性、水平向柔性的半刚性边界可显著减小边界对试样的约束作用;增大试样高度与底边的比值可有效减小刚性边界对试样端部的约束;半刚性复合加压块及柔性水囊对试验结果的影响很小。

Boundary effect tests of true triaxial apparatus for soil

In order to study the influences of rigid,half-rigid,and flexible boundaries on test results,unilateral loading tests on coarse-grained soil,with invariable horizontal stress and increasing vertical stress,were performed using the TSW-40 true triaxial apparatus developed by Hohai University. The results show that the restriction of the rigid boundary is clear on a cubic sample with the depth-width ratio of 1:1;using a half-rigid boundary on the top of a sample,with the rigid boundary in the vertical direction and the flexible boundary in the horizontal direction,can remarkably decrease the restriction of the boundary on the sample;the restriction of the rigid boundary on a sample can be effectively decreased by increasing the depth-width ratio of the sample;and half-rigid compound blocks and flexible water bags have a lesser influence on the test results.