Abstract:
To study ground deformations induced by earthquake, this paper aims to present an efficient sensing technique for capturing both translation and rotation of soil mass. The proposed magnetic tracking system uses permanent magnets as trackers and magnetom-eters as receivers. When permanent magnets, deployed within the soil to serve as excitation sources, move with the soil body during an earthquake, they generate static magnetic fields whose flux densities are related to the positions and orientations of the magnets. Magnetom-eters are used to detect the generated magnetic fields, which can be further used in calculating the magnets’ locations and orientations based on appropriate algorithms. For verification purpose, shaking table tests are performed and comparison between the sensing results with those obtained from a linear variable differential transducer (LVDT) shows excellent accuracy. Errors in the detection and frequency limit for capturing motion are analyzed. Finally, further applications of the proposed system are discussed.