XAGT-1型真三轴压力室结构完善和饱和砂土真三轴试验

介绍了西安理工大学开发的XAGT-1型真三轴仪。分析了该仪器在进行砂土真三轴试验过程中存在的问题,并提出了相应的完善措施。介绍了使用该仪器所进行的砂土的不同b值的应力路径试验。从试验结果发现,固结围压较低时,随着中主应力比增大,广义剪应力与广义剪应变曲线有硬化型逐渐转化为软化型;π平面上饱和砂土的破坏曲线轨迹比较接近于松冈—中井准则。固结围压较小时,随着中主应力比增大,强度试验点与松冈—中井准则的差异逐渐增大,固结围压较大时,达到200 kPa时,强度试验点与松冈—中井准则基本一致。

The complete of XAGT-1 type true tri-axial pressure chamber structure and the results of saturated sand

XAGT-1 type true tri-axial apparatus was developed by Xi"an University of Technology. The problems during the process of true tri-axial tests of sand by the true tri-axial apparatus were analyzed, and the corresponding improvement measures were proposed. Finally, the stress path tests of sand in different b values were carried out by the equipment. The experimental results show that when the confining pressure is low, with increasing of the principal stress ratio, the generalized shear stress and the generalized shear strain curve change gradually from hardening into softening; the damage curve of saturated sand in the plane is close to Matsuoka-Naikai criterion, when confining pressure is small, with the increasing of principal stress ratio, tests points are different from Matsuoka criterion, but when confining pressure is high to 200kPa, the strength test points are well with Matsuoka criteria.