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Design Aids: Table of Contents

About the Design Aids
Table of Contents
Foreword
Preface
Acknowledgement


      CONTENTS


About the Handbook                                                                 xi
Contents                                                                           xiii
Acknowledgement                                                                    xix
Foreword                                                                           xxi
Preface                                                                            xxiii
1 Crushing Mills and Their Foundations - An Overview
1.1 Industrial Crushing Mills                                                      1-3
1.2 Crushing Mill Foundations                                                      1-3
1.2.1 Foundation Support System                                                    1.4
1.2.2 Foundation Design                                                            1-5
1.3 Dynamics Forces                                                                1-5
1.4 Field Performance and Feedback                                                 1-6


2 Dynamics of Mill Foundations
2.1 Crushing Mills and their Foundations                                           2-3
2.2 Theory of Vibrations - Dynamic Analysis                                        2-5
2.2.1 Vibration of a Spring Mass System                                            2-5
2.2.2 Vibration of a Spring Mass System with Translational Spring                  2-5
      2.2.2.1 Un-damped Spring Mass System                                         2-5
      2.2.2.2 Damped Spring Mass System                                            2-9
Example Problems - Basic Theory of Vibrations                                      2-14
      P 2.2-1 Undamped Spring Mass System - Translational Spring                   2-14
      P 2.2-2 Damped Spring Mass System - Vertical Translational Spring            2-15
2.3 Dynamic Considerations for Design of Mill Foundations                          2-17
2.3.1 Mass & Stiffness Parameters of Mill-Foundation System                        2-17
2.4 Dynamic Analysis                                                               2-18
2.4.1 Dynamic Analysis of Mill Pedestals                                           2-18
Example Problems - Mill Pedestal Vibrations                                        2-21
      P 2.4-1 Pedestal Supporting Machine                                          2-21
      P 2.4-2 Free Standing Pedestals                                              2-22
2.5 Dynamic Analysis of Mill Foundations                                           2-23
2.5.1 Dynamic Response Analysis of Mill Foundation                                 2-26
      2.5.1.1 Free & Forced Vibration                                              2-26
      2.5.1.1.1 Motion along Y (Vertical direction)                                2-27
      2.5.1.1.2 Motion about Y (Torsional Vibration)                               2-29
      2.5.1.1.3 Motion in X-Y Plane (Translation along X and Rocking about Z)      2-31
      2.5.1.1.4 Motion in Y-Z Plane: (Translation along Z and Rocking about X)     2-35
Example Problems - Mill Foundation Vibrations                                      2-40
      P 2.5-1 An Undamped Spring Mass System Supported by a Vertical Spring
      subjected to Vertical Dynamic Force                                          2-40
      P 2.5-2 An Undamped Spring Mass System supported by Torsional Spring
      subjected to Torsional Dynamic Moment                                        2-41
      P 2.5-3 Mill Foundation supported on Soil - Free Vibration -
      Foundation Natural frequencies                                               2-42
      P 2.5-4 Mill Foundation supported on Soil - Forced Vibration -
      Foundation Response                                                          2-45


3 Design Parameters
3.1 Mill (Machine) Parameters                                                      3-3
3.1.1 Machine Static Loads                                                         3-4
3.1.2 Machine Dynamic Loads (DL) for Dynamic Response                              3-5
3.1.3 Machine Operational Loads for Strength Design                                3-6
3.1.4 Vibration Limits for Crushing Mills                                          3-7
3.1.5 Machine Data Template (TP-M) for Machine Parameters                          3-8
3.2 Foundation Parameters                                                          3-10
3.2.1 Foundation Material                                                          3-10
3.2.2 Reinforced Cement Concrete (RCC)                                             3-10
3.2.3 Reinforcement                                                                3-12
3.2.4 Foundation Sizing                                                            3-12
3.2.5 Foundation Rigidity                                                          3-14
3.2.6 Foundation Mass Ratio                                                        3-14
3.2.7 Foundation Eccentricity                                                      3-14
3.2.8 Foundation Tuning                                                            3-15
3.2.9 Vibration Limits for Mill Foundation                                         3-16
3.2.10 Foundation Strength Design                                                  3-17
3.2.11 Minimum Reinforcement                                                       3-17
3.2.12 Foundation Data Template (TP-F) for Foundation Parameters                   3-18
3.3 Geo-Technical Parameters                                                       3-18
3.3.1 Foundations Supported over the Soil                                          3-18
3.3.1.1 Design Soil Parameters                                                     3-19
      3.3.1.1.1 Correlations between Various Dynamic Soil Parameters               3-19
      3.3.1.1.2 Corrections for Static Stress or Overburden Pressure               3-20
      3.3.1.2 Soil Damping                                                         3-21
      3.3.1.3 Soil Stiffness - Equivalent Soil Springs                             3-22
      3.3.1.3.1 Equivalent Soil Springs using Coefficients of Sub-grade
      Reactions                                                                    3-22
      3.3.1.3.2 Equivalent Soil Springs using Elastic Half Space Model             3-30
3.3.2 Foundation Supported over Piles                                              3-34
      3.3.2.1 Design Pile Parameters                                               3-35
      3.3.2.2 Pile Stiffness                                                       3-35
      3.3.2.3 Group Effect on Pile Stiffness                                       3-37
      3.3.2.4 Pile Damping                                                         3-38
      3.3.2.5 Equivalent Pile Stiffness                                            3-38
3.3.3 Data Template (TP-G) for Geo -Technical Parameters                           3-43
Example Problems Equivalent Soil Springs / Pile Stiffness                          3-44
      P 3.3-1 Vertical Vibration Resonance Test - Equivalent Soil Springs          3-44
      P 3.3-2 Cyclic Plate Load Test - Equivalent Soil Springs                     3-46
      P 3.3-3 Foundation on Piles - Equivalent Pile Stiffness                      3-48


4 Modeling and Analysis
4.1 Modeling                                                                       4-4
4.1.1 Machine                                                                      4-4
4.1.2 Foundation (Base Raft + Pedestals)                                           4-4
4.1.3 Equivalent Soil/Pile Springs                                                 4-5
4.1.4 Boundary Conditions                                                          4-6
4.1.5 Material Data                                                                4-6
4.1.6 Degree of Freedom Incompatibility                                            4-6
4.1.7 Vibration Isolation                                                          4-7
4.2 Dynamic Analysis                                                               4-7
4.2.1 Free Vibration Analysis                                                      4-7
4.2.2 Forced Vibration Response                                                    4-9
      4.2.2.1 Steady-State Response at Machine Operating Speeds                    4-9
      4.2.2.2 Response at Gear-Mesh Frequency                                      4-10
      4.2.2.3 Transient Response                                                   4-10
4.3 Strength Analysis & Design                                                     4-11
4.3.1 Load Cases and Load Combinations


5 Design of Crushing Mill Foundations
5.1 Design Methodic for Crushing Mill Foundations                                  5-3
5.1.1 Design Step 1 - System Data                                                  5-3
5.1.2 Design Step 2 - FE Modeling                                                  5-4
5.1.3 Design Step 3 - Soil/ Pile Springs for FE/SD Modeling                        5-4
      5.1.3.1 Foundation directly supported over soil - Equivalent Springs         5-4
      5.1.3.2 Foundation supported over Piles - Equivalent Pile Springs            5-4
5.1.4 Design Step 4: Foundation Sizing & Eccentricity                              5-4
      5.1.4.1 Foundation Sizing                                                    5-4
      5.1.4.2 Foundation Eccentricity                                              5-5
5.1.5 Design Step 5 - Free Vibration Analysis                                      5-5
      5.1.5.1 Pedestal Natural Frequencies                                         5-5
      5.1.5.2 Foundation Natural Frequencies                                       5-5
5.1.6 Design Step 6 - Forced Vibration Analysis                                    5-6
      5.1.6.1 Steady-State Response at Machine Operating Speeds                    5-6
      5.1.6.2 Response at Gear-Mesh Frequency                                      5-7
      5.1.6.3 Transient Response                                                   5-7
5.1.7 Design Step 7 - Strength Design                                              5-7
5.2 Design of a Typical Mill Foundation (Sample Problem)                           5-8
      P 5.2.1 Example Problem: A Typical Foundation comprising
      of a Base Raft and a few Pedestals supporting dynamic machines
      directly Supported over the Soil.                                            5-8
5.3 Design of Foundation                                                           5-10
5.3.1 Design using Finite Element Method (FEM)                                     5-10
      5.3.1.1 Design Step 1 - System Data                                          5-10
      5.3.1.2 Design Step 2 - FE Modeling                                          5-12
      5.3.1.3 Design Step 3 - Soil Springs for FE Modeling                         5-12
      5.3.1.4 Design Step 4 - Foundation Sizing & Eccentricity                     5-12
      5.3.1.5 Design Step 5 - Free Vibration Analysis                              5-13
      5.3.1.6 Design Step 6 - Forced Vibration Analysis                            5-16
      5.3.1.7 Summary of FEM Analysis - Natural Frequencies &
              Steady-State Response                                                5-19
5.3.2 Design using Structural Design Method (SDM)                                  5-20
      5.3.2.1 Design Step 1 System Data                                            5-20
      5.3.2.2 Design Step 2 Modeling                                               5-20
      5.3.2.3 Design Step 3 Foundation Sizing & Eccentricity                       5-20
      5.3.2.4 Design Step 4 - Soil Springs for FE Modeling                         5-20
      5.3.2.5 Design Step 5 - Free Vibration Analysis                              5-20
      5.3.2.6 Design Step 6 - Forced Vibration Analysis                            5-21
      5.3.2.7 Summary of SDM - Natural Frequencies & Steady-State
              Response                                                             5-22
5.3.3 Comparative Results of FEM & SDM results                                     5-23
5.3.4 Learnings from the Study                                                     5-25


6 Foundation for a Real-Life Crushing Mill Supported Directly
over the Soil 
6.1 Foundation for a Real-Life Crushing Mill                                       6-3
6.1.1 Mill Machine Data                                                            6-3
6.1.2 Foundation Data                                                              6-6
6.1.3 Geotechnical Data                                                            6-7
6.2 Foundation Design                                                              6-7
6.2.1 Design Step 1 - System Data                                                  6-7
6.2.2 Design Step 2 - FE Modeling                                                  6-9
6.2.3 Design Step 3 - Soil Springs for FE Modeling                                 6-9
6.2.4 Design Step 4 - Foundation Sizing & Eccentricity                             6-10
6.2.5 Design Step 5 - Free Vibration Analysis                                      6-15
      6.2.5.1 Pedestal Natural Frequencies                                         6-15
      6.2.5.2 Foundation Natural Frequencies                                       6-17
6.2.6 Design Step 6 - Forced Vibration Analysis                                    6-19
      6.2.6.1 Permissible Vibration Amplitude/ Velocity                            6-19
      6.2.6.2 Steady State Response at Machine Operating Frequencies               6-20
6.2.6.3 Response at Gear-Mesh Frequency                                            6-24
6.2.7 Design Step 7 - Strength Design                                              6-25


7 Foundation for a Real-Life Crushing Mill on Piles
7.1 Foundation Design of a Real-Life Crushing Mill                                 7-3
7.1.1 Mill Machine Data                                                            7-3
7.1.2 Foundation Data                                                              7-6
7.1.3 Geotechnical Data (Pile Parameters from Geo-Technical Report)                7-7
7.2 Foundation Design                                                              7-7
7.2.1 Design Step 1 - System Data                                                  7-7
7.2.2 Design Step 2 - FE Modeling                                                  7-8
7.2.3 Design Step 3 - Pile Springs for FE Modeling                                 7-9
7.2.4 Design Step 4 - Foundation Sizing & Eccentricity                             7-10
7.2.5 Design Step 5 - Free Vibration Analysis                                      7-12
      7.2.5.1 Pedestal Natural Frequencies                                         7-12
      7.2.5.2 Foundation Natural Frequencies                                       7-13
7.2.6 Design Step 6 - Forced Vibration Analysis                                    7-16
      7.2.6.1 Permissible Vibration Amplitude/ Velocity                            7-17
      7.2.6.2 Steady State Response at Machine Operating Frequency                 7-17
      7.2.6.3 Response at Gear-Mesh Frequency                                      7-20
7.2.7 Design Step 7 - Strength Design                                              7-21


8 Construction Aspects
8.1 Construction Joints                                                            8-5
8.2 Embedded Parts                                                                 8-5
8.3 Placing / Laying of Concrete                                                   8-6
8.3.1 Quality plan                                                                 8-6
8.3.2 Cold Joints                                                                  8-6
8.3.3 Segregation                                                                  8-6
8.3.4 Mass Concreting                                                              8-6
8.4 Grouting                                                                       8-7
8.5 Anchor Bolts                                                                   8-7
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