Large biaxial laminar shear box for 1-g shaking table tests on saturated sand

1-g shaking table test is one of the most advanced and effective methods to investigate the dynamic behavior of soils and underground structures during earthquakes. A crucial requirement for shaking table tests on soil bodies is to reproduce the free-field conditions. In this contribution, a large biaxial laminar shear box (biLSB) was designed and utilized specifically for the shaking table tests of deep saturated sand deposits under bidirectional seismic loading. The new biLSB features multiple stacked octagonal frames that offer minimal resistance to shear movements. To ensure the desired equivalent shear-beam deformation mode, interlayer connectors were installed between adjacent frames, allowing translational movements while preventing additional rotation and bending. Additionally, to facilitate a standardized procedure for preparing saturated sand specimens, two types of auxiliary equipment, including a plane-type sand pluviator and a controllable saturation system, were devised and manufactured. Two tests were conducted, one on the empty box and another with a soil column, to assess the performance of the developed biLSB. A quantitative analysis confirms that the boundary effect of the box imposed on the soil specimen was insignificant, as required by the design.