一种新型真三轴仪的研制与开发

真三轴仪是一种真实模拟主应力状态,且在任意应力路径下测试土力学特性的试验仪器。介绍了研制的一种新型真三轴仪,它具有轴向刚性板加载、侧向双轴液压柔性囊加载的三向加载方式;侧向双轴相邻液压囊之间采用径向弹性伸缩、平面弹性转动的薄壁钢板有效隔离技术;伺服步进电机驱动滚珠丝杆推进活塞产生压力的液压/体变控制器独立施加三向主应力的自动控制系统。真正实现了三向独立加载、互不干扰。经测试分析,仪器系统性能稳定。新型真三轴仪具有结构简单,操作方便,应力状态真实,应变测试准确,试验过程易于控制的特点。

Development of a new true tri-axial apparatus

A true tri-axial apparatus is usually applied to measure the mechanical characteristics of soil under the three-dimensional principle stress condition. A new true tri-axial apparatus with a new structural cell is developed by Geotechnical Engineering Institute of Xi’an University of Technology. By comparing loading ways of different true tri-axial apparatuses at home and abroad, the characteristics of the new true tri-axial apparatus are summarized as follows: ① A kind of hydraulic and volume apparatus with stepper motor servo-driven is developed, which is used to load independently the principal stress, and the corresponding automatic control system is developed. ② The cubic sample is loaded by a pair of vertical steel plate and two pairs of lateral latex film vesicas. ③ The neighboring vesicas are separated by the steel plate, which can flex elastically in the radial direction and turn elastically on the horizontal plane. Furthermore, the true tri-axial tests on remolded loess are executed by use of the new true tri-axial apparatus. The characteristics of the stress-strain curve of the true tri-axial tests on the remolded loess and the strength of the loess remodeling are analyzed under different water contents. The new true triaxial apparatus is simple in structure, convenient in operation, true in stress state, exact in measuring the strain state and manageable in testing process.