Contenido Load Testing of Bridges: Proof Load Testing and the Future of Load Testing

Load Testing of Bridges, featuring contributions from almost fifty authors from around the world across two interrelated volumes, deals with the practical aspects, the scientific developments, and the international views on the topic of load testing of bridges.

Volume 13, Load Testing of Bridges: Proof Load Testing and the Future of Load Testing, focuses first on proof load testing of bridges. It discusses the specific aspects of proof load testing during the preparation, execution, and post-processing of such a test (Part 1). The second part covers the testing of buildings. The third part discusses novel ideas regarding measurement techniques used for load testing. Methods using non-contact sensors, such as photography- and video-based measurement techniques are discussed. The fourth part discusses load testing in the framework of reliability-based decision-making and in the framework of a bridge management program. The final part of the book summarizes the knowledge presented across the two volumes, as well as the remaining open questions for research, and provides practical recommendations for engineers carrying out load tests.

This work will be of interest to researchers and academics in the field of civil/structural engineering, practicing engineers and road authorities worldwide.

Table of Contents

Part I Proof Load Testing of Bridges

Chapter 1 Methodology for Proof Load Testing

Eva O. L. Lantsoght


1.1 Introduction
1.2 Determination of target proof load
   1.2.1.Dutch practice
   1.2.2.AASHTO Manual for Bridge Evaluation methods
1.3 Procedures for proof load testing
   1.3.1. Loading methods
   1.3.2. Monitoring bridge behavior during the test
   1.3.3. Stop criteria
1.4 Processing of proof load testing results
   1.4.1. On site data verification of stop criteria
   1.4.2. Final verification of stop criteria
1.5 Bridge assessment based on proof load tests
1.6 Summary and conclusions
References

Chapter 2 Load Rating of Prestressed Concrete Bridges without Design Plans by Nondestructive Field Testing
David V. Jauregui, Brad D. Weldon, and Carlos V. Aguilar

2.1 Introduction
    2.1.1. Load rating of bridges
    2.1.2. Load testing of bridges
2.2 Inspection and evaluation procedures
    2.2.1. In depth inspection and field measurements
    2.2.2. Magnel diagrams
    2.2.3. Rebar scan
       2.2.3.1. Double T-beam bridges
       2.2.3.2. Box beam bridges
       2.2.3.3. I-girder bridges
    2.2.4. Load testing
    2.2.5. Serviceability rating using proof test  results
    2.2.6. Strength rating using load rating software
    2.2.7. Final load ratings
2.3 Case studies
    2.3.1. Bridge 8761 ( Double T-Beam )
    2.3.2. Bridge 8825 ( Box beam )
    2.3.3. Bridge 8588 ( I-girder )
2.4 Conclusions
References

Chapter 3 Example of Proof Load Testing from Europe
Eva O. L. Lantsoght, Dick A. Hordijk, Rutger T. Koekkoek, and Cor van der Veen

3.1 Introduction to viaduct Zijlweg
    3.1.1. Existing bridges in the Netherlands
    3.1.2. Viaduct Zilweg
        3.1.2.1 General information and history
        3.1.2.2. Material properties
        3.1.2.3. Structural systems and description of tested spann
3.2 Preparation of proof load test
   3.2.1. Preliminary assessment
   3.2.2. Inspection
   3.2.3. Effect of alkali.silica reaction
      3.2.3.1. Efect of alkali-silica reaction on capacity
      3.2.3.2. Load testing of ASR-affected viaducts
      3.2.3.3. Monitoring results
   3.2.4. Determination of target proof load and position
      3.2.4.1 Finite element model
      3.2.4.2.Resulting target proof load
   3.2.5. Expected capacity and behavior
   3.2.6. Sensor plan
3.3 Execution of proof load test
   3.3.1. Loading protocol
   3.3.2. Measurement and observations
      3.3.2.1. Load-defection curves
      3.3.2.2  Deflection profiles
      3.3.2.3. Stains and crack width
      3.3.2.4. Movement in joint
      3.3.2.5. Influence of temperature
3.4 Post-processing and rating
   3.4.1. Development of final graphs
   3.4.2. Comparison with stop criteria
      3.4.2.1. ACI 437-2M acceptance criteria
      3.4.2.2. German guideline stop criteria
      3.4.2.3. Proposed stop criteria
   3.4.3. Final rating
   3.4.4. Lessons learned and recomendations for practice
   3.4.5. Discussion and elements for future research
 3.5 Summary and conclusions
Acknowledgments
References

Part II Testing of Buildings

Chapter 4 Load Testing of Concrete Building Constructions
Gregor Schacht, Guido Bolle, and Steffen Marx

4.1 Historical development of load testing in Europe
   4.1.1. Introduction
   4.1.2. The role of load testing in the development of reinforced concrete construction in Europe
   4.1.3. Development of stanfards and guidelines
   4.1.4. Proof load testing overshadowed by structural analysis
   4.1.5. Futher theoretical and practical developments of the recent past
4.2 Load testing of existing concrete building constructions
   4.2.1. Principal safety considerations
   4.2.2. Load testing in Germany
      4.2.2.1. Introduction
      4.2.2.2. Basics and range of application
      4.2.2.3. Planning of loading tests
      4.2.2.4. Execution and evaluation
   4.2.3. Load testing in the United States
   4.2.4. Load testing in Great Britain
   4.2.5. Load testing in other countries
   4.2.6. Comparison and assessment
4.3 New developments
   4.3.1. Safety concept
   4.3.2. Shear load testing
4.4 Practical recommendations
4.5 Summary and conclusions
References

Part III Advances in Measurement Techniques for Load Testing

Chapter 5 Digital Image and Video-Based Measurements
Mohamad Alipour, Ali Shariati, Thomas Schumacher, Devin K. Harris, and C. J. Riley

5.1 Introduction
5.2 Digital image correlation (DIC) for deformation measurements
   5.2.1. Theory
   5.2.2. Equipment
   5.2.3  Strengths and limitations
      5.2.3.1. Strengths
      5.2.3.2. Limitations
   5.2.4.Case study
      5.2.4.1. Structural system details and instrumentation
      5.2.4.2. Testing
      5.2.4.3. Load testing sequence
      5.2.4.4. Results
5.3 Eulerian virtual visual sensors (VVS) for natural frequency measurements
   5.3.1. Theory
   5.3.2. Equipment
   5.3.3. Strengths and limitations
      5.3.3.1. Strengths
      5.3.3.2. Limitations
   5.3.4. Case studies
      5.3.4.1. Estimation of cable forces on a lift bridge using natural vibration frequencies
      5.3.4.2. Identifiying bridge natural vibration frequencies with forced vibration test
5.4 Recommendations for practice
   5.4.1. Digital image correlation ( DIC ) for deformation measurements
   5.4.2. Eulerian virtual visual sensors (VVS) for natural frequency measurements
5.5 Summary and conclusions
5.6 Outlook and future trends
Acknowledgments
References

Chapter 6 Acoustic Emission Measurements for Load Testing
Mohamed ElBatanouny, Rafal Anay, Marwa A. Abdelrahman, and Paul Ziehl

6.1 Introduction
6.2 Acoustic emission–based damage identification
   6.2.1. Definitions
   6.2.2. AE parameters for damage detection
   6.2.3. Damage indicators
      6.2.3.1. Intensity analysis
      6.2.3.2. CR-LR plots
      6.2.3.3. Peak cumulative signal strength ratio
      6.2.3.4. Relaxation ratio
      6.2.3.5. B-value analysis
      6.2.3.6. Modified index of damage
6.3 Source location during load tests
   6.3.1. Types of source location
   6.3.2. Zonal and one-dimensional source location
   6.3.3. 2D source location
   6.3.4. 3D source location and moment tensor analysis
      6.3.4.1. 3D source location  and moment tensor analysis
      6.3.4.2. Crack classification and moment tensor analysis
6.4. Discussion and recommendations for field applications
References

Chapter 7 Fiber Optics for Load Testing
Joan R. Casas, António Barrias, Gerardo Rodriguez Gutiérrez, and Sergi Villalba

7.1 Introduction
   7.1.1. Blackground of fiber optics operation
   7.1.2. Distributed optical fiber sensors ( DOFS )
   7.1.3. Scattering in  optical fibers
   7.1.4. State of the art of fiber optic sensors in load testing
   7.1.5. Advantages and disadvantages of fiber optic sensors versus other sensors for load testing
7.2 Distributed optical fibers in load testing
   7.2.1. Introduction
   7.2.2. Experiences in laboratory:validation of the system
      7.2.2.1. Bending testsof concrete slabs
      7.2.2.2. Shear tests of partially prestressed concrete beams
   7.2.3. Aplication of DOFS in real structures
      7.2.3.1. San Cugat bridge in Barcelona
      7.2.3.2. Sarajevo bridge en Barcelona
      7.2.3.3. Lessons learned from the field tests
7.3 Conclusions
Acknowledgments
References

Chapter 8 Deflection Measurement on Bridges by Radar Techniques
Carmelo Gentile

8.1 Introduction
8.2 Radar technology and the microwave interferometer
8.3 Accuracy and validation of the radar technique
   8.3.1. Laboratory test
   8.3.2. Comparison with position transducer data
8.4 Static and dynamic tests of a steel-composite bridge
   8.4.1. Description of the bridge
   8.4.2. Load test experimental procedures and radar results
   8.4.3. Ambient vibration test experimental procedures and radar results
8.5 A challenging application: structural health monitoring of stay cables
8.6 Summary
   8.6.1. Advantages and disadvantages of microwave remote sensing of deflections
   8.6.2. Recommendations for practice
   8.6.3. Future developments
Acknowledgments
References

Part IV Load Testing in the Framework of Reliability-Based Decision-Making and Bridge Management Decisions

Chapter 9 Reliability-Based Analysis and Life-Cycle Management of Load Tests
Dan M. Frangopol, David Y. Yang, Eva O. L. Lantsoght, and Raphael D. J. M. Steenbergen

9.1 Introduction
9.2 Influence of load testing on reliability index
   9.2.1. General principles
   9.2.2. Effect of degration
   9.2.3. Target reability index and applied loads
9.3. Required target load for updating reability index
   9.3.1 Principles
   9.3.2. Example viaduct De Beck.-information about traffic is not available
      9.3.2.1. Description of viaduct De Beck
      9.3.2.2. Determination of required target load
      9.3.2.3. Discussion of results
   9.3.3. Example Halvemaans Bridge- information about traffic is modeled
      9.3.3.1 Description of Halvemaans Bridge
      9.3.3.2.Determination of proof load
9.4 Systems reliability considerations
9.5 Life-cycle cost considerations
9.6 Summary and conclusions
References

Chapter 10 Determination of Remaining Service Life of Reinforced Concrete Bridge Structures in Corrosive Environments after Load Testing
Dimitri V. Val and Mark G. Stewart

10.1 Introduction
10.2 Deterioration of RC structures in corrosive environments
10.3 Reliability-based approach to structural assessment
10.4 Corrosion initiation modeling
   10.4.1. Carbonation-induced corrosion
   10.4.2. Chloride-induced corrosion
10.5 Corrosion propagation modeling
   10.5.1. Corrosion rate
   10.5.2. Cracking of concrete cover
      10.5.2.1. Time to crack initiation
      10.5.2.2. Time to excessive cracking
   10.5.3. Effect of corrosion on bond between concrete and reinforcing steel
   10.5.4. Effect of corrosion on reinforcing steel
      10.5.4.1. Loss of cross sectional area due to general corrosion
      10.5.4.2. Loss of cross-sectional area due to pitting corrosion
10.6 Effect of spatial variability on corrosion initiation and propagation
10.7 Influence of climate change
10.8 Illustrative examples
     10.8.1. Simple-span RC bridge-case study description
     10.8.2. Reliability-based assessment of remaining service life of the bridge subject to carbonation
     10.8.3. Reliability-based assessment of remaining service life of the bridge subject to chlorique contamination
10.9 Summary
References

Chapter 11 Load Testing as Part of Bridge Management in Sweden
Lennart Elfgren, Bjorn Täljsten, and Thomas Blanksvärd

11.1 Introduction
11.2 History
  11.2.1. Overview of development of recommendations
  11.2.2. Which aim of load test in provided
  11.2.3. Development of recommendations
11.3 Present practice
  11.3.1. Inspection regime of structures
  11.3.2. Levels of assessment of structures
  11.3.3. Configuration of the vehicles
  11.3.4. Development of the traffic
  11.3.5  Examples of load testing
11.4 Future
  11.4.1. Bridge management
  11.4.2. Numerical tools
  11.4.3. Fatigue
  11.4.4. Strengthening
  11.4.5. Full-scale failure tests
11.5 Conclusions
Acknowledgments
References

Chapter 12 Load Testing as Part of Bridge Management in the Netherlands
Ane de Boer

12.1 Introduction
12.2 Overview of load tests on existing structures
12.3 Inspections and re-examination
12.4 Conclusions and outlook
References

Part V Conclusions and Outlook

Chaper 13 Conclusions and Outlook
Eva O. L. Lantsoght

13.1 Current body of knowledge on load testing
13.2 Current research and open research questions
13.3 Conclusions and practical recommendations