Development and Assessment of Transparent Soil and Particle Image Velocimetry in Dynamic Soil- Structure Interaction

This research combines Particle Image Velocimetry (PIV) and transparent soil to investigate the dynamic rigid block and soil interaction. In order to get a low viscosity pore fluid for the transparent soil, 12 different types of chemical solvents were tested and the two best-matching pore fluids were identified. Transparent soil was adopted in the research as a substitute for natural sand. To examine the dynamic properties of transparent soil, a series of resonant column tests were carried out on dry silica gel under different confining pressures. The test results showed that transparent soil has a similar dynamic behavior as natural soil under low confining pressure. Hence, transparent soil can be used as an effective substitute for natural soil in the shake table test, in which the confining pressure is usually lower than 400 kPa. A neural network-based camera calibration algorithm was developed for the PIV technique. Its application was illustrated through a case study of a rectangular strip footing by modifying the MatPIV code. The neural network camera calibration model was also compared with the linear model and second-order polynomial model. The comparison proved that the neural network camera calibration model is the most effective method. Three shake table tests were conducted in this research. The free-field motion shake table test clearly showed the amplification effects as the wave propagated upward from the bottom. Two shake table tests conducted on a small-scale rigid wood model investigated the interaction between the block and the soil under the input of 2-Hz, 0.25inch and 2-Hz, 0.5-inch sinusoidal waves. The testing results from the shake table test showed that the rigid wood block failed by the bearing capacity type of failure. The larger amplitude of the input motion at the same frequency would more easily topple the rigid block. The shake table test has also showed the near-field and far-field effects due to the soil-structure interaction. The near-field soil motion was significantly influenced by the motion of the rigid block. The far-field soil motion was unaffected by the motion of the rigid block. This research shows that transparent soil combined with PIV can be a powerful tool for future research in the field of dynamic geomechanics.