Using laser displacement transducer scanning technique in centrifuge modeling of reverse fault-foundation interaction

摘要

Reverse fault deformation can cause severe damages of structures built on shallow foundations as observed in previous earthquakes. Centrifuge modeling has been a good approach to investigate the interaction mechanisms of reverse fault and shallow foundation due to the lack of well-documented field data. Displacement measurements of are of critical importance in centrifuge tests for observing responses of soils and shallow foundations. In this paper, Laser Displacement Transducer (LDT) scanning technique was applied to access multi-points (targets) and multi-directions (horizontal, vertical, and rotational) displacement measurements of sand and shallow foundations on ground surface in centrifuge modeling of reverse fault-foundation interaction. Besides, PIV (Particle Image Velocimetry) technique was adopted as well to measure displacements of sand from the front side. The results show that LDT scanning technique has enough accuracy to measure the displacements of sand and foundations on the ground surface. It tackles the limitations of displacement measurements by PIV and LVDT, e.g. underestimated displacements measured by Ply technique due to wall friction, and single point and single direction displacement measurements of LVDTs. The combination of LDT scanning technique and PIV technique is able to obtain more comprehensive displacement information of sand and foundations both at the ground surface and the front side of the soil container.