Effect of ground motion processing and filtering on the response of rocking structures

Abstract

With growing interest in rocking structures, it is important to quantify the effects of ground motion processing schemes on rocking response. To this end, this paper studied the influence of different ground motion correction schemes and parameter values on the rocking displacement spectrum. When the problem is treated on an individual ground motion basis, then it seems that ground motion correction does have an influence on the rocking response, especially for more slender blocks. This influence is larger for causal filtering. However, no specific trend related to the cut off period of the filter can be observed (at least for cut off periods longer than or equal to 10 s) or on the type of the recording device (analog or digital). On the other hand, when treating the problem statistically (by comparing the statistics of the response due to sets of ground motion, not a single ground motion), the effect is significantly reduced: The processing schemes do not induce any significant bias to the rocking response and the motion‐to‐motion variability seems more important than the ground motion correction method. This conclusion applies to both analog and digital records, both causal and acausal filters, and to all near field pulse like, near field no pulse like, and far field records.

Ground Motion Processing in Rocking Structures

“…The nature of noise and baseline tilts in analog records are very distinct from digital records [22]. A discussion of this different nature is offered in [22,26]. In digital records, the velocity trace noise typically appears to have a linearly increasing baseline offset.…”

“…It is also worth mentioning that discussions about usable spectral periods (often expressed relative to the filter corner period) are irrelevant to the rocking oscillator since its "period" is amplitude dependent and can take values from zero to infinity [1]. Verification of the adopted processing scheme is presented in [26]. Notably, in this study, the Zero Order Corrected (ZOC) record refers to the record with mean removed (mean of the pre-event portion as discussed earlier).…”

Displacement‐based design procedures for rigid block isolation

“…1 Further studies 2 highlighted the complexity of the rigid block response to real earthquakes, pointing out the high sensitivity to geometry and ground motion of this type of system. Recently, rigid block modeling has received attention for the assessment of the seismic vulnerability [3][4][5] of masonry structures [6][7][8][9] and nonstructural elements. [10][11][12][13][14][15] Further, a variety of experimental tests have been conducted to investigate the response of rocking objects during earthquakes, such as art objects, 16,17 and hospital cabinets.…”

Material Testing of Micro-Concrete and 3d-Printed Reinforcement for Use in Small-Scale Seismic Testing of Rc Structures

“…In an opinion paper by Bradley [2], these global level assumptions have been identified as a major source of error in numerical modeling of earthquake engineering problems. Uncertainty in earthquake engineering can be categorized into two main classes; ground motion uncertainty (e.g., [3], among others) and modeling uncertainty (e.g., [4][5][6], among others). Currently, time history analysis is considered as the state of the art in modeling the seismic response of RC structures at the system level.…”