Technical guide - Loading tests on road bridges and footbridges
This guide is intended to the building owners, the project superintendents, the engineers of the engineering and design departments and of the laboratories, which have to order, design, organize, carry out, and interpret the tests under load of the road and pedestrian bridges.
It describes the whole of the operations of preparation, realization and checking of the load tests, which make it possible to ascertain the good behaviour of the structures before their reception
This guide is intended to the building owners, the project superintendents, the engineers of the engineering and design departments and of the laboratories, which have to order, design, organize, carry out, and interpret the tests under load of the road and pedestrian bridges.
It describes the whole of the operations of preparation, realization and checking of the load tests, which make it possible to ascertain the good behaviour of the structures before their reception.
While awaiting the regulations of Eurocode >EN 1991-2, the tests of the road bridges are presently performed according to the Booklet 61 Title II of the common Specifications.
This guide is also meant to prepare the transition towards Eurocode, and to constitute the base of a normative document that will go with it.
In the mean time, the regulations of this guide must be included in the contracts binding the operators to the building owner. For this purpose, it includes standard clauses, which will have to be inserted in the administrative and technical parts of the engineering and construction contracts.
Contents
1 – The objective of the test............................................................................................................................................................... 9
1.1 – Purpose of this guide.................................................................................................................................................... 9
1.2 - The tests and the acceptance of structures...................................................................................................................... 9
1.2 - The objectives of the tests........................................................................................................................................... 10
1.3 - Regulatory context...................................................................................................................................................... 11
1.4 - Bridges subjected to testing......................................................................................................................................... 11
1.5 - Repaired or strengthened bridges................................................................................................................................. 12
2 - Test loads and physical measurements.................................................................................................................................... 13
2.1 - Pavement loads.......................................................................................................................................................... 13
2.1.1 - General static loads.................................................................................................................................................. 13
2.1.2 - General dynamic loads............................................................................................................................................. 13
2.1.3 - Local traffic loads..................................................................................................................................................... 14
2.2 - Footpaths and cycle lanes........................................................................................................................................... 14
2.3 - Pedestrian and cycle bridges....................................................................................................................................... 15
2.4 - Measured physical quantities....................................................................................................................................... 15
3 - Organization of the tests by the project manager .................................................................................................................... 16
3.1 - The role of tests in bridge construction.......................................................................................................................... 16
3.2 - The nature of the tests................................................................................................................................................. 16
3.3 - The actors engaged in the tests.................................................................................................................................... 17
3.4 - The conduct of the tests.............................................................................................................................................. 18
3.4.1 - The calculation note................................................................................................................................................. 18
3.4.2 - The test programme and the organization of loading operations.................................................................................... 18
3.4.3 - The resources employed to conduct the measurements............................................................................................... 18
3.4.4 - Preliminary inspection of the structure........................................................................................................................ 18
3.4.5 - Verification of the applied loads................................................................................................................................. 19
3.4.6 - Loading the bridge and measurements....................................................................................................................... 19
3.4.7 - Inspection after the tests........................................................................................................................................... 20
3.4.8 - Analysis of results and validation after the tests........................................................................................................... 20
3.4.9 - The case of certain bridges....................................................................................................................................... 21
4 - Calculation note for tests and analysis of results.................................................................................................................... 22
4.1 - Design hypotheses for the tests.................................................................................................................................... 22
4.2 - Calculation note for the tests........................................................................................................................................ 23
4.3 - Analysis of results....................................................................................................................................................... 24
5 - Taking of measurements and presentation of results ............................................................................................................. 25
5.1 - Data required for effective instrumentation..................................................................................................................... 25
5.1.1 - Geometrical and topographical characteristics............................................................................................................ 25
5.1.2 - Measurement programme......................................................................................................................................... 25
5.2 - Possible types of measurement.................................................................................................................................... 26
5.2.1 - General comments concerning metrological characteristics (based on NF X07-001 - December 94)................................. 26
5.2.2 - Displacement measurements.................................................................................................................................... 26
5.2.3 - Deformation measurements...................................................................................................................................... 26
5.2.4 - Rotation measurements............................................................................................................................................ 26
5.2.5 - Vibration measurements........................................................................................................................................... 27
5.2.6 - Weighing operations................................................................................................................................................. 27
5.3 - Presentation of results................................................................................................................................................. 27
6 - Test programmes for standard bridges..................................................................................................................................... 28
6.1 - Rigid frame bridges and frames.................................................................................................................................... 29
6.1.1 - Preliminary inspection of the bridge............................................................................................................................ 29
2.1.2 - Hypothesis note....................................................................................................................................................... 29
6.1.3 - Calculation note....................................................................................................................................................... 29
6.1.4 - Loading programme................................................................................................................................................. 29
6.1.5 - Interpretation........................................................................................................................................................... 29
6.1.6 - Possibility of simpler tests......................................................................................................................................... 29
6.2 - Slab bridges, wide rib bridges...................................................................................................................................... 30
6.2.1 - Preliminary inspection of the bridge............................................................................................................................ 30
6.2.2 - An example of a loading programme.......................................................................................................................... 30
6.3 - Paved beam bridges................................................................................................................................................... 32
6.3.1 - Preliminary inspection of the bridge............................................................................................................................ 32
6.3.2 - Hypothesis note....................................................................................................................................................... 32
6.3.3 - Calculation note....................................................................................................................................................... 32
6.3.4 - Loading programme................................................................................................................................................. 32
7 - Specific features of non-standard bridges................................................................................................................................ 33
7.1 - Decks that rest on rigid supports.................................................................................................................................. 33
7.1.1 - Torsionally rigid and transversally indeformable decks................................................................................................. 33
7.1.2 - Torsionally flexible and transversally rigid decks.......................................................................................................... 34
7.1.3 - Transversally deformable decks................................................................................................................................ 34
7.1.4 - Curved and skew bridges.......................................................................................................................................... 34
7.2 - Complex bridges......................................................................................................................................................... 34
7.3 - Local behaviour.......................................................................................................................................................... 36
7.4 - The measurement of reactions at support...................................................................................................................... 36
8 - Annex 1......................................................................................................................................................................................... 37
8.1 - Structure for which no deformation measurement is required ()........................................................................................ 37
8.1.1 - The objectives of the tests......................................................................................................................................... 37
8.1.2 - Organization of the tests........................................................................................................................................... 37
8.1.3 - Test loads............................................................................................................................................................... 37
8.1.4 - Calculation note....................................................................................................................................................... 38
8.1.5 - Test programme....................................................................................................................................................... 38
8.2 - Structure for which measurements of different types are required (5)................................................................................. 39
8.2.1 - The objectives of the tests......................................................................................................................................... 39
8.2.2 - Organization of the tests........................................................................................................................................... 39
8.2.3 - Test loads............................................................................................................................................................... 39
8.2.4 - Design hypotheses................................................................................................................................................... 40
8.2.5 - Calculation note....................................................................................................................................................... 40
8.2.6 - Test programme....................................................................................................................................................... 41
8.2.7 - Articles that relate specifically to various structures...................................................................................................... 42
8.2.8 - Test reports............................................................................................................................................................. 43
8.2.9 - Validation of the tests............................................................................................................................................... 44
9 - Annex 2................................................................................................................................................................................
