The wear behaviour of arch bridge bearings The first Van Brienenoord Bridge Author: Naveen Narain Stud.nr: 4035607 Date: 27/11/2012 Delft University of Technology Faculty of Civil Engineering and Geosciences Master of Science thesis report Student: Naveen Narain (4035607) Civil Engineering Structural Engineering Steel and Timber Structures Graduation committee: Prof.ir. F.S.K. Bijlaard (Delft University of Technology) Dr. M.H. Kolstein (Delft University of Technology) Dr.ir. M.A.N. Hendriks (Delft University of Technology) Ir. L.J.M. Houben (Delft University of Technology) Dr.Ing. J.S. Leendertz (Rijkswaterstaat) Page i Preface This thesis study was performed in order to finalize my Master of Science program in Civil Engineering with the track ‘Timber and Steel Construction’ within ‘Structural Engineering’ at the Delft University of Technology. To do so, I was offered an opportunity to analyse the wear behaviour of bridge bearings in the main office of Rijkswaterstaat, located in Utrecht, the Netherlands. This opportunity was made possible by Dr. Ing. H. Leendertz, who is part of the graduation committee as well as the committee of the European standards regarding structural bearings. During my graduation thesis I was able to acquire more knowledge about, for example, finite element modelling, bridges and their bearings. I therefore would like to thank Rijkswaterstaat and the graduation committee, which also provided for support and critical judgment. Naveen Narain Delft, November 2012 Page iii Summary Structural bearings are connections between the substructure and superstructure of the bridge and may allow translations and rotations. They also transmit the external forces, acting on the superstructure, to the foundation. In the past years the traffic loads and intensity on the European traffic system has continuously increased. Bridge bearings are therefore more subjected to the wear. Structural bearings are not only designed and fabricated according to the European standards NEN- EN 1337, but they are also tested according to these standards. The bearings are however not tested with the forces, translations and rotations which occur in practice. To make a critical judgement regarding these standards, the wear behaviour of a large arch bridge, the first Van Brienenoord Bridge, is analysed. The analysis is performed by means of a linear elastic, finite element model. The bridge model is then subjected to a modified fatigue load model based on the European standards for traffic loads NEN-EN 1991-2 and traffic measurements at the Moerdijk Bridge. Translations and rotation were consequently found along with the simultaneously occurring reaction forces. These results are compared to the qualification tests included in parts 2 (Sliding elements) and 5 (pot bearings) of the European standards for structural bearings. After the comparison between the obtained results from the finite element model and the tests values from the European standards for structural bearings, there is concluded that: the wear behaviour of arch bridge bearings can successfully be obtain by means of the analysis method used for this study; the slide paths in the tests are reached in one or two year, which is a very short time period; the there is no clear relationship between the test values and the service life of structural bearings; large resistant moment may occur due to restraining of the bearings by means of the friction force. The resistant moment, however, could not be analysed since friction could not be implemented better for the linear elastic model. According to this study, the following are recommended: The finite element model constructed for this study can be used for the analysis of dynamic amplifications and is therefore also recommended to do so; It is recommended to simulate the traffic crossing the first Van Brienenoord Bridge to gain more insight about the occurring slide paths since the lorry distance and the number of lorry simultaneously crossing bridge affects the final slide paths; A nonlinear analysis should be performed in order to study the effect of resistant moments on the global behaviour of the superstructure; Even though large slide paths are also found in the direction perpendicular to the main sliding direction, NEN-EN 1337-2 does not include tests for that direction. It is therefore recommended that bearings are tested in two directions; Since the finite element model is constructed such that also a fatigue analysis can be performed, it is recommended that this analysis should indeed be performed. Page v Table of contents 1. INTRODUCTION........................................................................................................................ 1 2. OBJECTIVE .................................................................................................................................. 2 3. PRECONDITIONS AND SCOPE OF THIS MASTER THESIS ............................................ 3 4. RESEARCH STRATEGY ............................................................................................................ 4 5. LITERATURE STUDY ............................................................................................................... 5 5.1. General ...................................................................................................................................................... 5 5.2. Rijkswaterstaat in brief .............................................................................................................................. 5 5.3. Structural bearings in historic perspective (1) ........................................................................................... 6 5.4. Structural bearings .................................................................................................................................. 12 5.4.1. Elastomeric bearings ....................................................................................................................... 13 5.4.2. Steel bearings ................................................................................................................................. 14 5.4.3. Pot bearings .................................................................................................................................... 14 5.4.4. Spherical PTFE bearings .................................................................................................................. 15 5.5. The European standards concerning pot and spherical bearings............................................................ 16 5.5.1. The NEN-EN 1337............................................................................................................................ 16 5.5.2. The relevant test for sliding elements (NEN-EN 1337-2) ................................................................ 16 5.5.3. The relevant test for pot bearings (NEN-EN 1337-5) ...................................................................... 19 5.6. Earlier studies .......................................................................................................................................... 20 5.6.1. Mechanical behaviour of the structural bearings of the Dintelhaven Bridge ................................. 20 5.6.2. Mechanical behaviour of the structural bearings of a steel plate-girder bridge ............................ 20 5.7. Summary.................................................................................................................................................. 21 6. THE FIRST VAN BRIENENOORD BRIDGE ....................................................................... 22 6.1. General .................................................................................................................................................... 22 6.2. Selection of the bridge ............................................................................................................................ 22 6.3. Location of the bridge ............................................................................................................................. 22 6.4. History of the bridge ................................................................................................................................ 23 6.5. Global geometry and description of the bridge ...................................................................................... 25 6.6. Layout of the bridge deck ........................................................................................................................ 28 Page vii 6.7. Support system ........................................................................................................................................ 28 6.8. Summary.................................................................................................................................................. 29 7. THE FINITE ELEMENT MODEL .......................................................................................... 30 7.1. General .................................................................................................................................................... 30 7.2. Requirements of the finite element model ............................................................................................. 30 7.3. Modelling of structural transitions .......................................................................................................... 34 7.4. Modelling the supports ..........................................................................................................................