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Dynamic Performance Investigation of Base Isolated Structures

By Ather K. Sharif


Contents

Introduction, Objectives and Outline of Thesis
1.1 Introduction
1.2 Objectives
1.3 Outline of Thesis

Railway-induced Vibration - Source and Propagation Characteristics
2.1 Introduction
2.2 Source Characteristics
2.3 Propagation Characteristics
2.4 Prediction of Groundborne Noise and Vibration
2.5 Conclusions

Effects of Railway-induced Vibration on Buildings
3.1 Introduction
3.2 Effects of Vibration on the Building Structure
3.3 Evaluation of Human Response to Vibration in Buildings
3.3.1 UK Guidance
3.3.2 Validity of VDV guidance in BS6472 (1992) for evaluating Train Vibration
3.3.3 Review of International Experience
3.4 Evaluation of Human response to Noise in Buildings
3.5 Effects of Vibration on Equipment
3.6 Conclusions

Alternative Vibration Control Measures
4.1 Alternative Vibration Control Measures
4.2 At Source
4.3 In Propagation Path
4.4 At Receiver
4.5 Discussion
4.6 Conclusions

Theoretical Aspects of Isolation
5.1 Theory of Isolation (SDOF model)
5.2 Alternative Damping Models
5.3 Alternative Methods to Estimate Damping Properties
5.3.1 Logarithmic decrement
5.3.2 Bandwidth of half power points
5.3.3 Nyquist Plot for Circle Fits
5.4 SDOF Base Isolation Models
5.5 MDOF Base Isolation models
5.6 Modal Density
5.7 Dynamic Vibration Absorber
5.8 Transient Pulses
5.9 Starting Transients / Steady State Response
5.10 Wave Interaction
5.11 Conclusions

Instrumentation and Data Processing
6.1 Introduction
6.2 Transducer
6.3 Digital Data Acquisition Considerations
6.4 Instrumentation
6.5 Signal to Noise ratio
6.6 Considerations for site deployment of Instrumentation
6.7 Post Processing for Spectral Representation
6.8 Transmissibility
6.9 Errors in Estimates
6.9.1 Random and Bias Errors on Auto Spectra
6.9.2 Random Error on Transmissibility
6.9.3 Propagation delays
6.9.4 Non-Stationary Data
6.10 Conclusions

Dynamic Performance Investigation - Case Study 1

Dynamic Performance Investigation - Case Study 2

Dynamic Performance Investigation - Case Study 3
9.1 Introduction
9.2 The Site
9.2.1 Isolated Structure - Eland House
9.2.2 Un-isolated Structure - Watney House
9.3 Measurement Locations
9.4 Instrumentation
9.5 Vertical Measurements
9.6 Horizontal Measurements
9.7 Comparison of Mean Results - Vertical & Horizontal
9.8 Groundborne Noise
9.9 Conclusions

Outline of Proposed International Standard
10.1 Standards Process - General Principles
10.2 Development of a British Standard
10.3 Development of an International Standard
10.4 Legal Status of Standards
10.5 Existing Standard Concerned with Base Isolation
10.6 The Need for an Additional Standard

Conclusions and Recommendations

DRAFT ISO Guidelines for the Measurement, Evaluation and Implementation of Base Isolation Systems to Attenuate Ground Vibration