Field Testing & Monitoring of Structural Performance

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The George E. Brown, Jr. Network for Earthquake Engineering Simulation (NEES) Program is a project funded under the NSF Major Research Equipment Program. This cooperative agreement, under the NEES Program, establishes at the University of California, Los Angeles (UCLA), a NEES equipment site for field testing and monitoring of structural performance. UCLA will design, construct, install, commission, and operate a mobile field laboratory for forced-vibration testing and earthquake aftershock monitoring of full-scale structures. This equipment will be operational by September 30, 2004 or earlier and will be managed as a national shared-use NEES equipment site, with teleparticipation capabilities, to provide new earthquake engineering research capabilities through field experimentation and monitoring through 2014. This NEES equipment site will be connected to the NEES collaboratory through the University's Abilene Internet2 connection, with 1 Gb/sec capabilities. Shared-use access and training will be coordinated through the NEES Consortium. This award is an outcome of the peer review of proposals submitted to program solicitation NSF 00-6, "NEES: Earthquake Engineering Research Equipment." The following equipment is provided under this award: (1) four state-of-the-art forced vibration sources that include one omni-directional eccentric mass vibrator with maximum force of 10 kips (continuous operation) and 20 kips (intermittent operation) over a frequency range of 0.1-4.2 Hz, two uni-directional eccentric mass vibrators with maximum force of 100 kips and frequency range of 0-25 Hz, and one linear inertial shaker with maximum force of 5 kips and programmable arbitrary force (or acceleration) time histories over a wide frequency range (0-60 Hz), (2) wireless sensor and data acquisition system (accelerometers, LVDT's, fiber optic gage readout unit, digitizers, routers, and workstations), (3) a cone penetration truck, equipped with a seismic piezocone, 20-ton hydraulic push capacity, side augers, and in situ soil vibration sensors, and (4) networking equipment (data concentrator, satellite uplink station) to allow for real-time data acquisition, processing, and world wide web broadcasting of experimental results. Large arrays of sensors will be placed in buildings and the surrounding foundation soils to obtain high spatial and temporal resolution response data at levels of detail that have not been previously possible. These structures will be excited in the linear and nonlinear range using linear and eccentric shaker systems, or in some cases, using quasi-static loading with actuators. The data obtained will lead to a better understanding of linear and nonlinear response mechanisms (including damage localization, soil-structure-foundation interaction effects, and nonstructural participation), and will aid in the development and verification of improved numerical models indispensable for the full realization of the performance-based earthquake engineering paradigm. The equipment can also be used for forced vibration experiments and aftershock monitoring of structures in the event of a large earthquake. UCLA will integrate this field testing facility into its undergraduate and graduate curricula and research program, post-earthquake reconnaissance involving students under the guidance of a mentor, and provide training opportunities for outside researchers.