Title: Elevated Foundations for Rotating Machines for High Speed Balancing Facilities

Author(s): Pericles C. Stivaros and Pablo A. Bruno

Publication: Symposium Paper

Volume: 348

Issue:

Appears on pages(s): 106-124

Keywords: machine foundations, dynamic loads, vibration, resonance, pile foundations

DOI: 10.14359/51732682

Date: 3/1/2021

Abstract:
This paper presents a case study involving the structural analysis and design of an elevated foundation plinth to support multiple pieces of rotating machines with different operating weights and speeds. The equipment is used to operate a high-speed balancing testing facility for turbines and rotors that are located within an adjacent testing chamber. This project comprised of several layout and design challenges, including vibration and resonance concerns, effects of multiple operating frequencies, plinth shape, and pile foundation effects. Major concern was to maintain the high precision and strict tolerance limitations required by the high-speed balancing operations. Elevated machine foundations integral with other structures possess many natural frequencies, both locally and globally. The traditional design rules-of-thumb are not adequate for analyzing and designing elevated machine foundations. A computer-based finite element analysis method is required to identify the multiple natural frequencies of a complicated foundation structure. The strength design of a machine foundation can become very challenging when trying to implement code requirements that are mostly applicable to building elements and not to massive concrete foundations. This study recognizes the need for the development of a design standard to include special design requirements for mass concrete machine foundations.