Table of Contents
Laminated elastomeric bearings – Use on bridges, viaducts and similar structures - Technical guide
Contents
Foreword
Chapter 1 - Introduction
1.1 – Why replace the 2000 guide?
1.2 – Scope and content
1.3 – Application of the standard NF EN 1337-3 in the Frenchnational context
1.4 – Scope
1.5 – Notations and symbols
Chapter 2 - Composition and description
2.1 – General principles of composition
2.2 – Component parts
2.2.1 - Composition
2.2.2 – The elastomeric material
What are the criteria for choosing one origin over another?
2.2.3 – Steel plates
2.2.4 – Sliding elements that may be required
2.2.4.1 - Composition
2.2.4.2 – Horizontal force
2.2.4.3 – Slide plate dimensions
2.2.5 – Anti-slipping and anti-lifting devices
2.3 – Manufacturing methods
Chapter 3 – Behaviour and dimensioning
3.1 - Introduction
3.2 – The characteristics of bearings
3.2.1 – Geometric definition
3.2.2 – The characteristics of elastomer
3.2.3 – The characteristics of internal plates
3.2.4 – The characteristics of external plates
3.2.5 – The characteristics of slide plates
3.3 – Dimensioning bearings
3.3.1 - Principles
3.3.2 – Bearing behaviour
3.3.2.1 – Behaviour under axial force
3.3.2.2 – Behaviour under a horizontal force
3.3.2.3 – Behaviour under a horizontal axis rotation
3.4 – Dimensioning verifications
3.4.1 – Basic verification
3.4.1.1 – Limiting distortion
3.4.1.2 - Traction in the metal plates
3.4.1.3 – Rotation limit condition
3.4.1.4 – Buckling stability
3.4.1.5 – Non-slip condition
3.4.1.6 – Pressure on the contact planes
3.4.2 – Assessment of actual contact surfaces and pressure to be distributed in thesupports
3.4.2.1 – Experimental results
3.4.2.2 – The assessment method proposed
3.5 – Layout on supports
Chapter 4 – Design principles for a structure with bearings
4.1 – General points – The regulatory context
4.2 - Dimensioning
4.2.1 - Introduction
4.2.2 – The area of the bearing
4.2.3 – The net height of the elastomer
4.2.4 – Plan dimensions
4.2.5 – Buckling stability
4.2.6 – Respecting the deformation limit
4.2.7 – Rotation stability
4.2.8 - Verifying the non-slip condition
4.2.9 – Plate dimensioning
4.2.10 – Determining pressure on supports
4.2.10.1 – A fully compressed bearing
4.2.10.2 – The case of a partial unsticking
4.3 – Calculating horizontal force on support heads on a structurewith typical bearings
4.3.1 – General points
4.3.2 – Determining force on support heads
4.3.2.1 - Deformation
4.3.2.2- Breaking force (dynamic)
4.3.2.3 – Digital application
4.4 - Calculating horizontal force on a structure with slidingbearings
4.4.1 – General points
4.4.1.1 – Numerical design values
4.4.1.2 – Operating loads to be applied for the calculation of horizontal force
4.4.1.3 - Friction coefficient for sliding bearings
4.4.1.4 - Horizontal force due to breaking
4.4.2 – Example of a calculation
4.4.2.1 – Characteristics of the structure.
4.4.2.2 – Pre-dimensioning bearings
4.4.2.3 – Horizontal force for sliding bearings
4.4.2.4 - Horizontal force for non-sliding bearings
4.4.3 - Conclusion as regards calculations on structures with sliding bearings
Chapter 5 - Controls
5.1 – General principles
5.2 – Production controls prior to CE marking
5.2.1 – The content of the CE certification
5.2.2 – Test methods
5.2.2.1 – Behaviour to short-term effects
5.2.2.2 - Behaviour to long-term effects
5.2.2.3 – Behaviour to environmental influences
5.2.2.4 –Behaviour to dynamic effects
5.2.3 – Compliance to the standard
5.3 – Controls on reception
5.4 – Controls on installation
5.4.1 – The drafting of prior documents
5.4.1.1 – The existence of specific procedures
5.4.1.2 – The provisional operating state of bearings
5.4.2 – Controls during construction
5.5 – Controls of behaviour in service
Chapter 6 – The pre-dimensioning and verification program
Appendix 1 – Calculations for laminated elastomericbearings for use in seismic zones
A1-1 – Regulatory framework
A1-2 – Design combinations and direction accumulation
A1-2.1 – Seismic action
A1-2.2 - Combinations with other load cases
A1-3 - Dynamic calculation model
A1-3.1 - Shear modulus G
A1-3.2 - Modelling of bearingsFigure A2: mass beam design modelWhen a deck lies on laminated elastomeric bearings, it is the bearings that provide the most flexibility to the structure. It istherefore essential that they are taken into account in the dynamic model that enables the natural periods to be calculated. Intheory, the bearing should be modelled by a multi-directional spring that functions both in traction-compression androtation, that is, by six stiffnesses (figures A2 and A3).
A1-4 – Using a behaviour factor
A1-4.1 – The two seismic design methods
A1-4.2 – Elastomeric bearings on all the supports
A1-4.3 - Elastomeric bearings on part of the supports
A1-5 - Recommendations
A1-5.1 – Maximum distortion
A1-5.1.1 – Total distortion
A1-5.1.2 - Distortion due to horizontal force
A1-5.2 - Buckling
A1-5.3 - Slippage
A1-6 – Further construction measures
A1-6.1 – Elastomeric bearing that take up seismic forces
A1-6.1.1 – Seismic couplings as safety stops
A1-6.1.2 – Elastomeric bearings supplemented by a blocking device taking up seismicforces
A1-6.1.3 – Elastomeric bearings in conjunction with a sliding device
A1-6.2 – Minimum support rest
Appendix 2 – The durability of laminated elastomericbearings with a sliding plane
A2-1 – The characteristic quantity of the functioning of a slidingbearing
A2-2 – Measures to be taken at the design stage
A2-3 – Measures to be taken at the manufacturing stage
A2-4 – Measures to be taken as part of the monitoring process
A2-5 - Conclusion
Appendix 3 - Table of dimensions
Type B bearing with e = half-sheet
Appendix 4 – Assistance with drafting Particular TechnicalClauses (CCTP)
A4.1 - Examples of clauses to be included in the chapter "quality ofmaterials"
A4.2 - Examples of clauses to be included in the chapter "designprinciple”
A4.3 - Examples of clauses to be included in the chapter"implementation"
Bibliography
General documents
Standards
Bibliography specific to Appendix 1
