Structure-soil interaction for framed structures under dynamics loading caused by reciprocating compressor

Abstract

Gas compressors are key components of industrial plants in oil refining, mainly acting as mechanical energy suppliers to chemical processes. Among the types of compressors, the reciprocating ones are highlighted. Due to mandatory demands of chemical process and industrial arrangement, such equipment is commonly installed on framed structures. This condition and the typical movement of mechanical parts of the compressors generate dynamic loads which frequently cause unacceptable vibrations. The work aim at evaluate the dynamic behavior of a system consisting of a framed structure, a reciprocating compressor, foundation in piles and the soil itself. For this purpose, parametric study is developed from a finite element model and field measurements. The parametric study goal is to establish ranges of local soil parameters within which the dynamic behavior of a system can be understood and measured. The parameters so-called constant coefficient of horizontal reaction (nh) of natural soil which typically occurs in an industrial area located in Araucária, Paraná state, Brazil, are then evaluated. The evaluation of the dynamic behavior of the system through the developed models is benchmarked by field measurements of effective velocity of vibration in the actual structure, obtained by instrumentation. The soil parameters are obtained by back analysis of tests results by using a model widely used in design offices: model proposed by Miche[1]. It takes into account the variation of the soil parameters with depth. Yet the other goal is to evaluate the influence of the soil parameters obtained by static and cyclic horizontal loading tests, the later ones being proposed to simulate the dynamic effect on the soil. Finally, the article presents comparisons of the results provided by the finite element model in terms of natural frequencies of vibration.