DESIGN AND PERFORMANCE OF A LARGE-SCALE SOIL LAMINAR SHEAR BOX IN SHAKING TABLE TEST

摘要

The liquefaction of saturate sand is an eye-catching problem in geotechnical earthquake engineering. Amongst the various remedial measures available, the use of stone columns is one of the most popular choices. This paper describes the design, fabrication and performance of a large-scale single axis laminar shear box to investigate the behavior of composite foundation of stone columns. A laminar shear box is a flexible container that can be placed on a shaking table to simulate vertical shear-wave propagation during earthquakes through a soil layer of finite thickness. Based on the seismic response of the semi-infinite free-field sand deposit, a large-scale laminar shear box, which can simulate prototype soil layer boundary conditions, is designed. The inner dimension of laminar shear box is 3m in length, 1.5m in width and 1.8m in height. The container consists of fifteen, rigid rectangular, laminar frames supported individually by bearings connected to an external frame so that the weight of the box is transferred off the table using an external frame. The bearings connected to external frame are used to facilitate smooth relative displacement between adjacent frames. The design details of the box are provided in addition to results of dynamic tests performed to commission the box. The results of this study show that the laminar box does not impose significant boundary effects and is able to maintain 1-D soil column behavior. Furthermore, the laminar box designed in this research can be adopted in other tests for seismic geotechnical problems.