Development Centre forApplied Dynamics
Machine Foundation Design
Competency Centre for Frame and Block Foundation
Rotary, Reciprocating, Impact Machines and Vibration Isolation
Note to Industry
The cost of machine foundation is but a small fraction of that of the equipment and inadequately constructed foundations may result in failures and shutdowns exceeding many times the cost of the capital investment required for properly designed and built foundations.
The importance of machine foundation design was not recognised in the past. Simple methods of calculation were used most often involving the multiplication of static loads by an estimated Dynamic Factor , the result being treated as an increased static load without any knowledge of the actual safety factor. Because of this uncertainty, the value of the adopted dynamic factor was usually too high, although practice showed that harmful
deformations resulted during operation even when these excessive factors were used.
This necessitated a deeper scientific investigation of dynamic loading.
The performance, safety and stability of machines depend largely on their design, manufacturing and interaction with environment. In principle machine foundations should be designed such that the dynamic forces of machines are transmitted to the soil through the foundation in such a way that all kinds of harmful effects are eliminated. Many scientists have contributed to the field of machine foundation laying great emphasis on vibration response of machine foundation system and contributed greatly to the practical and theoretical development of the subject. Study of vibration problems associated with machine foundations necessitated investigations to determine the natural frequencies of foundations.
The design aids/methodologies provide insight in to the dynamic behaviour of foundation
and its components for satisfactory performance of the machine thus suggesting the need
for the complete knowledge of load transfer mechanism from the machine to the foundation and the knowledge of excitation forces and associated frequencies for correct evaluation of machine performance.
The Observations from the Failure Analysis Investigations and Review of Machine Foundations Behaviour conducted on various types of machines for various industrial projects viz. Petrochemicals, Refineries, Power plants etc. over the last few decades, suggest need for improvement in the design of foundations for better performance of machines. The outcome suggests the need for more comprehensive evaluation of Site Soil Data, better understanding of Machine Data and improvement in the Design Philosophy. These in turn call for improvement in:
- Modeling Technique
- Analysis Technique
- Structural Design Process, and
- Construction Technology
The rich experience of the author, in analysis, design and field investigations of variety of machine foundations during last about 45 years, is available for sharing with the practicing engineers engaged in design of machine foundation. Emphasis is laid to provide deeper understanding to the practicing engineers about the physical understanding of the dynamic behaviour of machine foundation system.
The rich experience has also been translated into a handbook
on design of machine foundation for practicing engineers. This book covers basic fundamentals necessary for understanding and evaluating dynamic response of machine foundation system. Stress is laid on detailed dynamic analysis for evaluating the response. Use of Finite Element packages, commercially available in the market, for analysis and design of the foundation are recommended. The author has carried out extensive field investigations on many foundations the findings of which are presented for comparison with analytical results.
This book is written with the sole objective of making the practicing engineer physically understand and feel the dynamics of machine foundation system.