A Novel Bidirectional Dynamic Triaxial Instrument and Its Applications

This article reports the development of a novel bidirectional dynamic triaxial instrument. According to the seismic analysis of soil mechanics for major geotechnical engineering projects, there is an absence of instrumentation to simulate level and horizontal earthquake loads and hence a new design is reported here. The bidirectional dynamic triaxial instrument was built using a hydraulic servo system, which had excellent dynamic response and generated bidirectional excitation force/stress with designed amplitude ratios, phases, and waveforms. Advanced digital image measurement was used to characterize the dynamic deformation of soil in three dimensions. The application of the digital image processing is described in detail. The axial average length, radial average diameter, average cross-sectional area, and volume of soil were easily determined. This non contact measurement is an innovation showing that bidirectional excitation with varying amplitude and phase were satisfactory. The deformation of the so...