Monitoring earthquake-induced loading with camera networks: case study in Sherman Oaks, California

Abstract

The advent of high speed, CCD-based camera technologies opens new possibilities for field monitoring applications. In particular, under natural or man-made loading conditions, applying these new technologies towards the monitoring of building interiors may substantially help rescue and reconnaissance crews during post-event evaluations. To test such a methodology, we have developed a specialized network of high-speed cameras and supporting hardware for monitoring and tracking nonstructural elements subjected to vibration loading, within building structures. Teamed with the University of California, Los Angeles, a full-scale vibration experiment is conducted on a vacant structure damaged during the 1994 Northridge Earthquake. The building of interest is a four-story office building located in Sherman Oaks, California. The investigation has two primary objectives: (1) to characterize the seismic response of an important class of equipment and building contents and (2) to study the applicability of tracking the response of these equipment and contents using arrays of image-based monitoring systems. In this paper, we describe the image acquisition (hardware and software) system and the experimental field set-up are described. In addition, the underlying communication, networking and synchronization of the camera sensor system are discussed.