“Dynamic Analysis of Large Compressor Foundations in Industrial Plants”


 
by
Dr. Song F. Jan, P.E.
Bechtel Corporation
Houston, TX
 

Abstract

Over the past decade, the capacities of large process compressors have increased substantially.  Subsequently, the concrete structures and pedestals supporting these units are becoming taller and larger - resisting higher static and dynamic loads.  Moreover, in industrial plants such as refineries, chemical plants, gas plants and power plants, it's normal practice to support multiple compressors on a common mat due to space limitations.  For this case, the effect of interaction between units on dynamic responses can be significant and should be considered in the design.  For plants located in high seismic zones, a dynamic response spectra analysis adds even greater complexity.  Therefore, the design of a compressor pedestal becomes one of the most challenging and sophisticated foundation designs on an industrial project.

 

This paper presents analytical and design steps for designing multiple dynamic equipment foundations on a common mat using GT STRUDL.  The powerful dynamic analysis and concrete design capabilities in GT STRUDL simplify and automate the complex design task that will save the project significant design time.

The analysis and design of a foundation supporting two large units of compressor and gas turbine will be used to illustrate the design steps.

The following design steps will be presented:

§Machine data

§Seismic loads and design spectra

§Geotechnical data

§Design loads

§Design criteria

§Sizing pedestals and foundation

§Finite element modeling

§Harmonic analysis for vibration responses

§Seismic response spectra analysis

§Static analysis with UBC earthquake loads

§Evaluating seismic design forces based on steps 9 and 10

§Reinforced concrete design with ACI seismic provisions

The required GT STRUDL input data and commands will be discussed during the presentation.
 


Biographical Data

Dr. Song Jan is Principal Engineer at Bechtel Corporation for 28 years. He is expert in the areas of structural dynamics, finite element analysis, steel and reinforced concrete design. He has extensive design experiences in refineries and chemical plants, LNG structures, Delayed coker units, nuclear and conventional power plants.

Education

Ph.D.   Engineering Mechanics, University of Texas at Austin, 1971

M.S.    Civil Engineering, Texas A&M University, 1966