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Analysis of wave propagation within buildings in response to earthquakes enables the tracking of changes in dynamic characteristics using impulse response functions. The velocity of traveling shear waves and the intrinsic attenuation of buildings can be retrieved, providing valuable input for system identification. The Factor Building at the University of California, Los Angeles campus (henceforth referred to as the UCLA Factor Building), an instrumented 15-story steel moment frame structure, is selected for dynamic response characterization. Shear wave travel time and attenuation are computed from wave propagation using seismic interferometry applied to recorded motions, with deconvolved waves used to compute these parameters. In this study, the natural logarithm of the envelopes of waveforms deconvolved with the basement signal provided the measure of attenuation. Additionally, the waveforms deconvolved with the basement motion, indicating the building’s fundamental mode. The frequency and time decay further constrained the shear velocity and attenuation. Shear velocity was determined using arrival times measured from deconvolved waves, resulting in an average velocity of 147.1 m/s. The observed quality factor was 10.8, with a corresponding damping ratio of 5%. The shear wave velocity and damping ratio estimates derived from deconvolved waves showed consistency with those obtained from basement deconvolved waveforms. This consistency validates wave deconvolution as an effective method for isolating building response from excitation and ground coupling. By incorporating the resonant frequencies and damping ratios derived from previous analyses into a refined element model, this study underscores the potential of wave deconvolution for extracting building dynamic characteristics, thereby enhancing our understanding of their responses to earthquakes.

Seismometer self-noise levels were determined using Sleeman's three-sensor method in combination with the Welch method for different parameter combinations. The self-noise levels decreased with the increasing segment window length, which is equivalent to the subwindow length, and with the increasing segment overlap rate for different frequency points at a fixed band. After the statistical examination of 9800 different parameter combinations, a zone of reasonable self-noise calculation parameter combinations was identified. Reasons for the unsuitability of certain parameter combinations were explored with respect to their distortion of the seismometer's self-noise levels.

The sensor orthogonality and azimuth accuracy of a seismometer at a seismic station are generally important parameters for data quality control. These parameters can be estimated using suitable methods with an appropriately defined coordinate system and related angle set. We compare three methods with synthetic data and real data to investigate their validity and consistency. Using synthetic data generated from real records of an instrument system (which is composed of an STS2.5 seismometer connected to an Q330HRS recorder), numerical experiments reveal relationships between estimation errors and statistical noise level, as well as timing error. Because the original method described by Tasič and Runovc (2013) discards some possible solutions, it can lead to an ambiguous azimuth result. This can be avoided by taking into account complete solutions, as well as by constraining the vertical inclination and orthogonal deviation solutions to quadrants I and IV. This can lead to results that are closer to possible physical conditions. Real records at stations BJT, Jiujiang, and Mengcheng are processed, including microseism and earthquake event data. All three methods yield consistent results once the method of Tasič and Runovc (2013) is modified to consider the complete solutions and the constraints of physical conditions. If different data recorders are used for the reference and test seismometers, sample time shifts can affect the estimated vertical axis inclination angle; this can be used to assess timing offset between the two recorders. [ABSTRACT FROM AUTHOR]