Measurement and interpretation of dynamic loads in bridges

European Commission Directorate-General For The Information Society And Media Directorate-General For Research And Innovation

Description

Phase 3: Fatigue behaviour of orthotropic steel decks
Industrial research and development

Informations

• Publié par: EUROPEAN-COMMISSION-DIRECTORATE-GENERAL-FOR-THE-INFORMATION-SOCIETY-AND-MEDIA-DI
• Nombre de lectures: 37
• Langue: English
• Poids de l'ouvrage: 2 Mo

Extrait

Commission of the European Communities
technical steel research
Properties and service performance
Measurement and interpretation of dynamic
loads in bridges
Phase 3
Fatigue behaviour of orthotropic steel decks
Synthesis Report
EUR 13378 EN 3
Commission of the European Communities
technical steel research
Properties and service performance
Measurement and interpretation of dynamic
loads in bridges
Phase 3
Fatigue behaviour of orthotopic steel decks
Edited by:
A. Bruls
Service 'Ponts et Charpentes'
Université de Liège
Quai Banning 6
B-4000 Liège
Contract No 7210-KD/119/201 /317/411 /609/807
(1 July 1986 to 31 December 1988)
Synthesis report
Directorate-General
Science, Research and Development PARI [UROP Biblioth.
1991 N.C. EUR 13378 EN Published by the
COMMISSION OF THE EUROPEAN COMMUNITIES
Directorate-General
Telecommunications, Information Industries and Innovation
L-2920 Luxembourg
LEGAL NOTICE
Neither the Commission of the European Communities nor any person acting
on behalf of then is responsible for the use which might be made of
the following information
Cataloguing data can be found at the end of this publication
Luxembourg: Office for Official Publications of the European Communities, 1991
ISBN 92-826-0532-9 Catalogue number: CD-NA-13378-EN-C
© ECSC-EEC-EAEC, Brussels • Luxembourg, 1991
Printed in Belgium SUMMARY.
This research, carried out with the financial help of the ECCS, concerned the
fatigue strength of orthotropic steel decks of road bridges. It followed two
phases that were concerned with the collection of traffic data and measurement
of stresses produced in bridges. Fatigue tests under constant and variable
amplitude were carried out on stiffener-plate connections, stiffener-stiffener
connections with U and V shapes, and stiffener cross-beam connections. From
the tests results and calculations some conclusions can be drawn which are
directly usable in bridge design. However, some unexpected behaviour occured
and some connections need more investigation.
Résumé.
Cette recherche, réalisée avec l'aide financière de la CECA, concernait la
résistance à la fatigue des dalles orthotropes de ponts-routes. Elle faisait
suite à deux phases qui se sont concentrées sur la collecte de données
relatives aux charges du traffic et aux contraintes produites dans les ponts.
Les essais de fatigue sous amplitude constante et variable ont été réalisés
sur les assemblages raidisseur en U-tôles, les assemblages
raidisseur-raidissèur en U et en V, les assemblages raidisseurs-entretoise.
Les résultats des essais et les calculs ont permis de tirer des conclusions
directement applicables au calcul des ponts-routes. Néanmoins des
comportements imprévisibles s'étant manifestés, certains assemblages demandent
des investigations complémentaires.
Zusammenfassung.
Dieses Forschungsvorhaben wurde mit finanzieller Unterstützung der EGKS
durchgeführt und betraf das ErmUdungsverhalten orthotroper Platten von
Strassenbrüchen. Es folgte auf zwei Phasen, in denen hauptsachlich Daten über
Verkehrslasten sowie Beanspruchungen von Brücken gesammelt wurden.
Ermüdungsversuche unter konstanten und variablen Amplituden wurden für
folgende Verbindungen durchgeführt : U-Längsverstelfung/Blech, U-und
V-Längsversteifung, und Längsversteifung/Quertrager. Die Ergebnisse der
Versuche und der Rechnungen erlaubten Schussfolgerungen, die direkt für die
Auslegung von Brücken anwendbar sind.
Aufgrund unerwarteter Verhaltenswesen der untersuchten Bauteile sind jedoch
zusatzliche Forschungen notwendig. This report is a synthesis of the final reports performed
by each Laboratory that has participated
to the common research :
1. H.LEHRKE, Fraunhofer Institut fUr Betriebsfestigkeit, Bartningstrasse H7 _
6100 Darmstadt - Germany. [1]
2. A. BRULS, E. POLEUR, Service "Ponts.et Charpentes", Université de Liège,
6, quai Banning - 1)000 Liège - Belgique. [2]
3. A. BIGNONNET, I.R.S.I.D. 78105 Saint-Germain-en-Laye - France, and
J. CARRACILLI, B. JACOB, L.C.P.C., 58, Bd. Lefebvre - 75732 Paris - France.
C3]
k. S. CARAMELLI, P. CROCE, M. FR0LI, L. SANPAOLESI, Istituto di Scienza delle
Costruzioni, Università di Pisa, Via Diotisalvi, 2 - 56126 Pisa - Italy.
cu
5. H. KOLSTEIN, J. DE BACK, Stevin Laboratory, Universiteit van Delft, 2628 CN
Delft, Nederland. [5]
6. C. BEALES, Transport and Road Research Laboratory, Old Wokingham Road,
Crowthorne, United Kingdom [6].
Coordination : A. BRULS
IV CONTENTS
Page
SUMMARY 111
RESUME
ZUSAMMENFASSUNG
1. INTRODUCTION 1
1.1 Orthotropic steel deck
1.2 Details tested
2. METHODOLOGY OF FATIGUE PREDICTION 5
2.1 Traffic loads and effects on bridges
2.2 Classical life calculation 6
2.3 The fracture mechanic approach 9
3. CONNECTION STIFFENER-PLATE 12
3.1 Types of connection
3.2 Stress determination
3.3 Fatigue testing and results5
3.4 Fatigue life calculation9
3.5 Crack propagation and lifetime calculations 20
3.6 Conclusion 2
4. CONNECTION STIFFENER-STIFFENER 4
4.1 Types of connections
4.2 Stress determination
4.3 Test results of the University of Pisa2
4.4 Test results of the T.U. DELFT
4.5 Comparison with other research programs 51
4.6 Conclusions 5
5. CONNECTION STIFFENER-CROSSBEAM 70
.5.1 Types of connection
5.2 Stress determination
5.3 Test results of TRRL2
5.4ts of the T.U. Delft5
5.5 Test results of the L.B.F.7
5.6 Conclusions 79
6. ORTHOTROPIC DECK TO CROSSBEAM CONNECTION 106
7. APPLICATIONS 111
8. CONCLUSIONS
BIBLIOGRAPHY5 1. INTRODUCTION.
1.1. ORTHOTROPIC STEEL DECKS (Fig. 1.1).
Orthotropic steel decks are used in bridges with long spans and
in movable bridges in which dead weight has to be as low as possible.
The upper part of these decks is composed of a plate on which the
traffic runs. This plate is covered by a thin surfacing (7 to 12 mm) or an
asphalt surfacing (MO to 70 mm).
Longitudinal stiffeners are welded to the under part of the deck
plate, approximately 300 mm. apart, parallel to the direction of the
traffic lanes. They are usually closed sections with trapezoidal or "V"
shapes although open sections are sometimes used. The stiffeners transmit
loads to crossbeams to which they are connected.
Crossbeams are normally spaced at 3 to 5 meters and are connected
to main girders or diaphrams.
Orthotropic steel decks are very sensitive to fatigue damage
because they are directly subjected to the actions of wheel loads which
give rise to stress ranges which are high compared to the dead load
stresses especially if the surfacing is thin.
In order to understand the fatigue behaviour of orthotropic steel
decks, the path of the traffic loads must be considered. Under the action
of wheels, the deck plate acts as a beam on elastic supports (the stiffener
webs). The elasticity of the supports decrases with the spacing of the
crossbeam. The web of the stiffeners are subjected to normal forces
(support reaction) and to bending moment if stiffeners have closed
sections.
Longitudinally the stiffeners are subjected to shear forces,
bending and torsion moments. The butt-welds connecting the longitudinal
stiffeners and the stiffener to crossbeam connection bear these effects.
1.2. Details tested.
This research concerns the study of the fatigue strength of
orthotropic decks with closed stiffeners. Bibliographical researches and
bridge examinations made during the two first phases have enabled us to
define details which are most sensitive to fatigue damage (Fig. 1.1).
- 1 -* detail 1 stiffener to deckplate connection,
* detail 2 r to stiffener,
stiffener to crossbeam connection, * detail 3
* detail H bolted connection crossbeam-orthotropic plate.
For each detail, the stress field was studied by calculation
and/or by measurement in the laboratory. Afterwards constant amplitude
fatigue tests were carried out to define the S-N curves. Finally specimens
were tested under variable amplitude load cycles simulating traffic
effects.
Distribution of the work between laboratories was as follows :
* detail 1 : stiffener to deck plate connection :
- University of Liège analysed local stresses with the help of
a finite band program and tested the connection under constant
and variable amplitude loading ;
- IRSID carried out constant amplitude tests on this connection
with a different welding procedure to that in the University of
Liège.
- L.C.P.C. developed and applied a fracture mechanics model.
* Detail 2 : stiffener to stiffener connection :
- University of Pisa measured and calculated stresses on a full
size orthotropic deck ;
- University of Liège calculated stress histograms produced by
traffic loads using the results of the 1st and 2nd phases ;
- University of Pisa and T.U. Delft tested different designs of
thi