Center for Embedded Network Sensing
Forced Vibration Testing of a Four-Story Reinforced Concrete Building Utilizing the nees@UCLA Mobile Field Laboratory
- Author(s): Yu, Eunjong
- Skolnik, Derek
- Whang, Daniel H.
- Wallace, John W.
- et al.
Published Web Locationhttps://doi.org/10.1193/1.2991300
The nees@UCLA mobile ﬁeld laboratory was utilized to collect forced and ambient vibration data from a four-story reinforced concrete (RC) building damaged in the 1994 Northridge earthquake. Both low amplitude broadband and moderate amplitude harmonic excitation were applied using a linear shaker and two eccentric mass shakers, respectively. Floor accelerations, interstory displacements, and column and slab curvature distributions were monitored during the tests using accelerometers, linear variable differential transformers (LVDTs) and concrete strain gauges. The use of dense instrumentation enabled veriﬁcation of common modeling assumptions related to rigid diaphragms and soil-structure-interaction. The ﬁrst six or seven natural frequencies, mode shapes, and damping ratios were identiﬁed. Signiﬁcant decreases in frequency cor responded to increases in shaking amplitude, most notably in the N-S direction of the building, most likely due to preexisting diagonal joint cracks that formed during the Northridge earthquake. DOI: 10.1193/1.2991300