FOUNDATIONS FOR INDUSTRIAL MACHINES

ปัญหาของฐานรากเป็นเรื่องใหญ่สำหรับโรงงานอุตสาหกรรม ยิ่งที่เกี่ยวข้องกับก๊าซ-สารเคมี การออกแบบต่างๆ ยิ่งจะต้องใช้ความระมัดระวังสูง ไม่ใช่แค่การประมาณ เรื่อง Dynamics Load แต่ต้องมีความชัดเจนเรื่องรอบของการสั่น และความต่อเนื่องของแรงด้วย (ISOLATE)

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

LINK to This Handbook : http://www.machinefoundation.com/book.html

Eng Tip Forum - Dynamic Loaded Machine Foundation

http://www.eng-tips.com/viewthread.cfm?qid=110197&page=6

Geotechnical Engineers Area

http://www.eng-tips.com/threadcategory.cfm?lev2=12

University, Hyderabad B.Tech SOIL DYNAMICS AND MACHINE FOUNDATION - Question paper บททดสอบ

http://www.indiastudychannel.com/exams/ExamPaper22862.aspx

CONTENTS ดูว่าที่เคยรู้ หรือที่มีอยู่ แตกต่างหรือเหมือนอย่างไร เพื่อหาความเข้าใจเพิ่มเติม  

About The Handbook
1 Machines and Foundations
1.1           An Overview
1.2           Design Philosophy
1.3           Machine Foundation System
1.4           Machines
1.5           Foundation
1.5.1         Block Foundation
1.5.2         Frame Foundation
1.5.3         Tuning of Foundation 
1.5.4         Foundation Material 
1.5.5         Foundation Analysis and Design
1.6           Soil
1.7           Vibration Isolation
1.8           Field Performance and Feedback
 
               PART - I
          THEORY OF VIBRATION 
BASIC UNDERSTANDING WITH SPECIFIC APPLICATION 
                  TO 
       MACHINE FOUNDATION DESIGN
2.             Single Degree of Freedom System 
2.1           Free Vibration
2.1.1         Undamped System - SDOF Spring Mass System 
2.1.2         Damped System
2.2           Forced Vibration
2.2.1         Undamped System - Dynamic Force Externally Applied
2.2.2         Damped System - Dynamic Force Externally applied
2.2.3         Damped System - Dynamic Force Internally Generated
2.2.4         Damped System - Dynamic Excitation Applied At Base 
2.2.5         Undamped System - Subjected to Impact Loads
2.2.6         Undamped System - Subjected to Impulsive Loads
Example Problems
 
 
3.             Multi-Degree of Freedom Systems
3.1           Two Degree of Freedom System - Free Vibration - Undamped
3.1.1         Two Spring Mass System- Linear Springs
3.1.2         A Rigid Block supported by Vertical and Translational Springs
3.1.3         A Rigid Block Supported by Vertical and Rotational Springs
3.1.4         A Rigid Block supported by Translational and Rotational Springs
3.1.5  Multiple Spring Mass Systems connected by a massless Rigid Bar
3.1.6  A Portal Frame supporting mass at Beam Center
3.2           Two Degree of Freedom System - Forced Vibration
3.2.1         Undamped Two Spring Mass System
3.2.2         Undamped Two Spring Mass System- Subjected to Impact Load
3.2.2         A Rigid Block supported by Translational & Rotational Springs 
3.2.4         Multiple Spring Mass Systems connected by a massless Rigid Bar
3.2.5  A Portal Frame supporting mass at Beam Center
3.3           Three Degree of Freedom System - Free Vibration
3.3.1         Three spring mass system
3.3.2         A Rigid Block supported by Vertical, Translational & Rotational Springs 
3.4           Three DOF System - Forced Vibration
3.4.1         Three Spring Mass System subjected to Harmonic Excitation
3.4.2         A Rigid Block supported by Vertical, Translational & Rotational Springs subjected to Harmonic Excitation
Example Problems
 
4.             Vibration Isolation
4.1.1         Principle of Isolation
4.1.2         Transmissibility Ratio
4.1.3         Isolation Efficiency
4.1.4         Isolation Requirements 
4.1.5         Selection of Isolators
Example Problems
               PART - II
           DESIGN PARAMETERS
5.             Design Sub-grade Parameters 
5.1           Introduction 
5.2           Soil Aspects Influencing Soil Structure Interaction
5.2.1         Energy Transfer Mechanism 
5.2.2         Soil Mass Participation in Vibration of Foundations
5.2.3         Effect of Embedment of Foundation 
5.2.4         Applicability of Hook’s Law to Soil 
5.2.5         Reduction in Permissible Soil Stress 
5.2.6         Damping in Soil
5.3           Dynamic Soil Parameters
5.3.1         Dynamic Soil Modulus
5.3.2         Coefficients of Subgrade Reaction
5.4           Design Soil Parameters
5.4.1         Variation with respect to static Stress or Overburden Pressure
5.4.2  Variation with respect to Base Contact area of Foundation
5.5           Equivalent Springs  
5.5.1         Foundation Supported Directly over Soil
5.5.2         Foundation Supported over an Elastic Pad
5.5.3         Foundation Supported on a Set of springs
5.5.4         Foundation Supported over Piles 
Example Problems
 
6.             Design Machine Parameters 
6.1           Parameters for Rotary Machines
6.1.1         Dynamic Forces
6.1.2         Transient Resonance  
6.1.3         Critical Speed of Rotors 
6.1.4         Rotor Bearing Supports 
6.1.5         Forces due to Emergency and Faulted Conditions 
6.1.6         Coupling of Machines
6.2           Parameters for Reciprocating Machines
6.2.1         Dynamic Forces
6.2.2         Transient Response 
6.2.3         Forces due to Emergency and Faulted Conditions 
6.2.4         Coupling of Machines
6.3           Parameters for Impact Machines
6.3.1         Machines producing repeated Impacts - Forgs Hammers
6.3.2         Machines producing Impulse/Pulse Loading
6.4 Amplitudes of Vibration
Example Problems
 
 
7.             Design Foundation Parameters
7.1           Foundation Type
7.2           Foundation Material
7.2.1         Concrete
7.2.2         Reinforcement
7.3           Foundation Eccentricity
7.4 Foundation Tuning
7.4.1         Under-tuned Foundation
7.4.2         Over-tuned Foundation
7.5 Foundation Stiffness and Mass Parameters
7.6 Other Miscellaneous Effects
7.7 Vibration Limits in Machine Foundation Design
7.8 Block Foundation
7.8.1         Foundation Sizing
7.8.2         Foundation Stiffness
7.8.3         Strength Design
7.8.4  Minimum Reinforcement
7.9 Frame Foundation
7.9.1         Foundation Sizing
7.9.2         Stiffness Parameters
7.9.3         Strength Design
7.9.4  Minimum Reinforcement
               PART - III
         DESIGN OF FOUNDATIONS
         FOR REAL LIFE MACHINES
8.             Modelling and Analysis
8.1           Manual Computational Method
8.1.1         Block Foundation
8.1.2         Frame Foundation
8.2           Finite Element Method
8.2.1         Mathematical Modeling
8.2.2         Machine
8.2.3         Foundation
8.2.4         Soil
8.2.5         Dynamic Forces
8.2.6         Boundary Conditions
8.2.7         Material Data
8.2.8         Degree of Freedom In-compatibility
8.3 Dynamic Analysis
8.3.1         Free Vibration Response
8.3.2         Forced Vibration Response
8.4 Strength Analysis and Design
8.4.1         Block Foundation
8.4.2         Frame Foundation
Example Problems
 
 
9.             Foundations for Rotary Machines
9.1           Design of Block Foundation
9.1.1         Dynamic Analysis
9.1.2         Amplitudes of Vibration
Design Example- Foundation for Low Speed Machine
9.2 Design of Frame Foundation
9.2.1  Dynamic Analysis
9.2.2  Lateral Mode of Vibration
9.2.3  Vertical Mode of Vibration
9.2.4  Lateral Vibrations Coupled with Torsional Vibrations
Design Example- Foundation for Turbo Generator
 
 
10.           Foundation for Reciprocating Machines
10.1 Design of Block Foundation
10.1.1  Dynamic Analysis
10.1.2  Amplitude of Vibration
Design Example- Foundation for a Reciprocating Engine
Design of Frame Foundation
Design Example- Foundation for a Reciprocating Compressor
 
 
11.           Foundation for Impact and Implusive Load Machines
11.1 Hammer Foundation
11.1.1  Foundation Sizing
11.1.2  Dynamic Analysis
Design Example- Foundation for a Drop Hammer
11.2 Foundation for Machines Producing Impulsive Loads
11.2.1  Foundation Sizing
11.2.2  Dynamic Analysis
Design Example- Machine Producing Implusive Loads Applied at Repeated Interval
               PART - IV
         DESIGN OF FOUNDATIONS
                 WITH
       VIBRATION ISOLATION SYSTEM
12. Vibration Isolation System
12.1 Vibration Isolation Design
12.1.1  Sizing of Inertia Block
12.1.2  Selection of Isolators
12.1.3  Location of Isolators
12.1.4  Dynamic Analysis
Design Example- Vibration isolation for a Fan Foundation
Design Example- Vibration isolation for a Crusher Foundation
               PART - V
 CONSTRUCTION ASPECTS & CASE STUDIES
13. Construction Aspects
13.1 Construction Joints
13.2 Embedded Parts
13.3 Placing/Laying of Concrete
13.4 Grouting
 
 
14. Case Studies
14.1 Introduction
14.2 Case Studies
Example- High Vibrations of a Motor Compressor Unit
Example- 210 MW Turbo-Generator unit - High Vibration Problems
Example- Reciprocating Compressor on Isolation pads
Example- Vibration Isolation of FD Fan Foundation