Development and application of novel hollow cylinder apparatus

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 medium-high frequency with the intact clay samples, separately. The results proved the HCA's capability of simulating the complicated stress path including principal stress rotation.