Evaluation of Soil Dynamic Properties Using Shake Table Tests on Laminar Shear Box and Its Numerical Verification

A simplified, single-axis laminar box, which consists of a lightweight aluminum alloy hollow novel sectional configuration, was designed, fabricated, and tested in-house. Laminates were placed one above another, and ball bearings were positioned between two frames for free movement of the frames in one direction. Shake table tests were then carried out by fixing the base of the box on the table to study the propagation of vertical seismic waves through dry sand of the Sabarmati River. This work deals with design details of the box and experimental evaluation of the soil dynamic characteristics when the laminar box is subjected to sine-wave excitation and real earthquake excitation. It was observed that the influence of boundary effects in the laminar box was negligible. Furthermore, the fundamental frequency of the soil was observed to be in the range of 11–13 Hz, and near the surface of the soil, the maximum amplification factor of the input motion was about 4.2. There was an increase in the soil damping ratio with increasing excitation levels. Numerical simulation was carried out using both a 1-D model with free-field boundary conditions and a 3-D finite-element model of the laminar box. It was observed that the 1-D analysis with free-field boundary conditions gave conservative results.