Amplification Factors for Equipment Design Subjected to Seismic Loading

Abstract

A mathematical technique is developed to evaluate the seismic response of primary equipment supported directly by the main structure and also the response of secondary equipment supported by the primary equipment. The method can be used for structures ranging from the simple to the complex, and is amenable to calculations based on standard spreadsheet or numerical software or, if desired, can be programmed. The technique can be used to develop amplification factors for seismic motion between ground, structure, and equipment. Alternatively, the method can be utilized to develop the ground response (or structure motion) spectra for various structural damping ratios and also floor response (or equipment response) spectra directly from a ground motion spectrum given as datum. The results are compared with the results from other well-established methods. The proposed method has an advantage over the other methods in that it enables direct computation of the third level response, i.e., response of the secondary equipment supported by the primary equipment; also, the method can be readily applied to any shape of ground motion response spectrum given as datum.