Generation of synthetic accelerograms for telecommunications equipment: fragility assessment of a rolling isolation system

This paper assesses the safety of a double conical rolling isolation system designed for protecting telecommunications equipment using a probabilistic approach. Due to the limited number of input accelerograms in the GR-63-CORE guideline for telecommunications equipment (only one), eight different filters are optimized to best capture the required response spectrum. The fitted filters are incorporated into an easy-to-implement framework, which is used to generate several suites of accelerograms for the probabilistic analyses. The results of these analyses are analyzed and discussed to reveal the shortcomings of the GR-63-CORE guideline, which in general are the limited number of accelerograms and ignoring the potentially important low frequency accelerations in the prescribed accelerogram. It is shown that the prescribed accelerogram may not be representative of excitations that are expected to be experienced by telecommunications equipment or the isolation systems protecting them, and is, hence, not conservative. Moreover, the results of the probabilistic analyses are presented in the form of fragility curves that can guide the design of rolling isolation systems.