为研究交通、波浪等荷载产生的主应力轴循环旋转应力路径对土体性状的影响,研制了可以在轴力、扭矩中高频率下共同变载的空心圆柱仪(HCA),并分析了设备的技术参数和性能指标.在静态试验环境下,设备的内外围压、轴力和扭矩均可独立控制;在动态试验环境下,轴力和扭矩可作任意波形周期变化,变载频率可达5Hz.传感器工作性能稳定,测量精度高,有多重校合,并配备了非接触式水下应变传感器.通过开发专用切样装置,利用该设备对原状黏土样进行初步试验,分别验证了仪器实现主应力轴旋转特殊应力路径以及在中、高频率下轴力和扭矩的任意波形变载功能,说明此空心圆柱仪具备模拟包括主应力轴旋转在内的复杂应力路径的工作能力.
A novel hollow cylinder apparatus (HCA) was developed to investigate the influence of cyclic principal stress rotation induced by traffic or wave loads on soil's properties, which could afford a combined axial-torsional loading system at medium-high frequency. And the HCA's technical index and loading characteristics were analyzed. This apparatus can control the inner, outer pressure, axial load and torque independently under static tests; and it can achieve the periodical change of axial load and torque in the predefined random form under high dynamic tests (5 Hz). The transducer system works stably and has high accuracy and multiple checking, moreover the non-contact underwater proximity sensors are equipped. A special cutting device was designed to investigate the apparatus' performance of realizing the special principal stress rotation stress path and the random vibration of axial load and torque at mediumhigh frequency with the intact clay samples, separately. The results proved the HCA's capability of simulating the complicated stress path including principal stress rotation.