Monitoring interstory drift in buildings under seismic loading using MEMS inclinometers

Accurate measurements of interstory drift are of great importance to the emerging performance-based structural health monitoring (SHM). Previous studies have shown the potential of obtaining interstory drift via rotation measurements. In the present study, an optimal layout of Micro Electro Mechanical Systems (MEMS) inclinometers is proposed to improve the monitoring accuracy. First, detailed study on the deformation mode of a single column in both elastic and elastoplastic stages was carried out with emphasis on the development of the plastic hinge in reinforced concrete (RC) columns. The optimal layout for deploying inclinometers on a column was put forward with acceptable monitoring error anticipated using the deformation mode. Then, tests on three identical RC columns installed with inclinometers according to the optimal layout showed stable inclinometer performance and verified the feasibility of the proposed monitoring method by comparing with drift monitored by displacement transducers. The test also verified the deformation mode in theoretical analysis and proved that the development of plastic hinge length can roughly be monitored by the inclinometers. Finally, the influence of various factors on the monitoring error was discussed in detail.