Structural bearings and expansion joints for bridges ( PDFDrive )

Structural Engineering Documents Gunter Ramberger Structural Bearings and Expansion Joints for Bridges I International Association for Bridge and Structural Engineering Association lnternationale des Ponts et Charpentes lnternationale Vereinigung fur Bruckenbau und Hochbau IABSE AIPC IVBH Copyright 02002 by International Association for Bridge and Structural Engineering All rights reserved No part of this book may be reproduced in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without permission in writing from the publisher ISBN 3-85748-105-6 Printed in Switzerland Publisher: IABSE-AIPC-IVBH ETH Honggerberg CH-8093 Zurich, Switzerland Phone: Int + 41-1-633 2647 Fax: Int + 41-1-633 1241 E-mail: secretariat@iabse.ethz.ch Web: http://www.iabse.ethz.ch Table of Contents Bearings 1.1 Introduction 1.2 The role of bearings 1.3 General types of bearings and their movements 1.4 The layout of bearings 1.5 Calculation of bearing reactions and bearing movements 1.6 Construction of bearings 1.7 Materials for bearings 1.8 Analysis and design of bearings Installation of bearings 1.10 Inspection and maintenance I Replacement of bearings I Codes and standards 1.13 References 7 16 19 29 33 37 38 39 41 42 Expansion Joints 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 2.10 Introduction The role of expansion joints Calculation of movements of expansion joints Construction of expansion joints Materials for expansion joints Analysis and design of expansion joints Installation of expansion joints Inspection and maintenance Replacement of expansion joints References 51 51 51 58 70 72 84 86 87 88 Dedicated to the commemoration of the late Prof Dr techn Ferdinand Tschemmernegg, University of Innsbruck Preface It is my hope that this treatise will serve as a textbook for students and as information for civil engineers involved in bridge construction My intent was to give a short guideline on bearings and expansion joints for bridge designers and not to mention all the requirements for the manufacturers of such products These requirements are usually covered by product guidelines, which vary between different countries Not all the references are related to the content of this document They are more or less a collection of relevant papers sometimes dealing with special problems I express many thanks to Prof Dr.-Ing Ulrike Kuhlmann, University of Stuttgart, chairperson of Working Commission of IABSE, who gave the impetus for this work; to her predecessor of the IABSE Commission, Prof Dr David A Nethercot, Imperial College of Science, Technology and Medicine, London, for reviewing the manuscript, and Prof Dr Manfred Hirt, Swiss Federal Institute of Technology, Lausanne, for his contributions and comments I wish to thank J S Leendertz, Rijkswaterstaat, Zoetermeer; Eugen Briihwiler, Swiss Federal Institute of Technology, Lausanne; Prof R J Dexter, University of Minnesota; G Wolff, Reissner & Wolff, Wels; Schimetta t, Amt der 00 Landesregierung, Linz; Prof B Johannsson, LuleA Tekniska Universitet, for amendments, corrections, remarks and comments I thank also my assistant Dip1.-Ing Jorgen Robra for his valuable contributions to the paper, especially for the sketches and drawings, and my secretaries Ulla Samm and Barbara Bastian for their expert typing of the manuscript Finally, I would like to thank the IABSE for the publication of this Structural Engineering Document Vienna, April 2002 Gunter Ramberger Bearings 1.1 Introduction All bridges are subjected to movements due to temperature expansion and elastic strains induced by various forces, especially due to traffic loads In former times our bridges were built of stones, bricks or timber Obviously, elongation and shortening occurred in those bridges, but the temperature gradients were small due to the high mass of the stone bridges Timber bridges were small or had natural joints, so that the full elongation values were subdivided into the elongation of each part On the other hand, the elongation and shortening of timber bridges due to change of moisture is often higher than that due to thermal actions With the use of constructional steel and, later on, of reinforced and prestressed concrete, bridge bearings had to be used The first bearings were rocker and roller bearings made of steel Numerous rocker and roller bearings have operated effectively for more than a century With the development of ageing-, ozone- and UV-radiation-resistant elastomers and plastics, new materials for bearings became available Various types of bearings were developed with the advantage of an area load transmission in contrast to steel bearings with linear or point load transmission, where elastic analysis leads theoretically to infinite compression stresses For the bearings the problems of motion in every direction and of load transmission were solved, but the problem of insufficient durability still exists Whilst it is reasonable to assume the life of steel bearings to be the same as that of the bridge, the life of a bearing with elastomer or plastic parts can be shorter 1.2 The role of bearings The role of bearings is to transfer the bearing reaction from the superstructure to the substructure, fulfilling the design requirements concerning forces, displacements and rotations The bearings should allow the displacements and rotations as required by the structural analysis with very low resistance during the whole lifetime Thus, the bearings should withstand all external forces, thermal actions, air moisture changes and weather conditions of the region 1.3 General types of bearings and their movements Normally, reaction forces and the corresponding movements follow a dual principle a non zero bearing force corresponds to a zero movement and vice versa An exception is given only by friction forces which are nearly constant during the movement, and by elastic restraint forces which are generally proportional to the displacement Usually, the bearing forces are divided into vertical and horizontal components Bearings for vertical forces normally allow rotations in one direction, some types in all directions If they also transmit horizontal forces, usually vertical forces are combined Bearings A special type of bearing transmits only horizontal forces, while allowing vertical displacements The following table (Table 1.3-1) shows the common types of bearings, including the possible bearing forces and displacements Friction and elastic restraint forces are not considered Symbol Function + Construction All translation fixed Rotation all round Point rocker bearing Pot bearing; Fixed elastomeric bearing; Spherical bearing Horizontal movement in one direction Rotation all around Constr point rocker sliding bearing; Constr pot sliding bearing; Const elastomeric bearing; Constr spherical sliding bearing Horizontal movement in all directions Rotation all round Free point rocker bearing; Free pot sliding bearing; Free elastomeric bearing; Free spherical sliding bearing; Link bearing with universal joints (tension and compression) All translation Line rocker bearing Leaf bearing fixed (tension and Rotation about one axis compression) Horizontal movement in one direction Rotation about one axis Roller bearing; Link bearing (tension and compression); Constant line rocker sliding bearing Horizontal movement in all direction Rotation about one axis Free rocker sliding bearing; Free roller bearing; Free link bearing ~ All horizontal tranal fixed Rotation all round HoriLontal force bearing Horizontal movement in one direction Rotation all round Guide bearing 1.4 The layout of bearings Tuble 1.3-1 8.2 1.4 The layout of bearings 1.4.1 General Bearings can be arranged at abutments and piers (fig 1.4.1-1 ; fig 1.4.1-2) under the webs of the main girders, under diaphragms (fig 1.4.1-3), and under the nodes of truss bracings The webs and the diaphragms of concrete bridges have to be properly reinforced against tensile splitting; steel bridges need stiffeners in the direction of the bearing reactions to transfer the concentrated bearing loads to the superstructure and the substructure Abutments and piers also have to be properly reinforced under the bearings against tensile splitting -77 Fig I I - I : Bearings at an abutment I - , ~- ~ I Fig 1.4.1-2: Bearings at u pier I7 Fig 1.4.1-3: Bearing at a single pier 10 Bearings The layout of the bearings should correspond to the structural analysis of the whole structure (super- and substructure together!) If the settlement and the deflection of the substructure can be neglected the structural analysis of the superstructure, including the bearings, can be separated from that of the substructure Sometimes the model for the analysis, especially of the superstructure, will be simplified by assuming the following: bearings are situated directly on the neutral axis of the girder (fig 1.4.1-6),the motion of the bearings occurs without restraint, bearings have no clearance, etc In this case we must consider the correct system (fig 1.4.1-5) at least for the design of the bearings and take into account the influence of the simplifications on the structure & Fig I 4.1-4: Reality A Fig I 4.1-5: Correct system On the abutments or separating piers it is normal to use at least two vertical bearings to avoid torsional rotations At intermediate piers one or more vertical bearings may be used If more than one bearing is used the rotational displacement at the pier is restrained More than three vertical supports of the superstructure lead to statically indeterminate bearing conditions, but even the simplest bridge has at least four vertical bearings If the torsional stiffness of the superstructure is low (e.g open cross sections) it may be neglected and the layout with four bearings becomes isostatic If the torsional stiffness is not negligible (e.g box girders) we have to take it into account for the structural analysis, especially for skewed and curved bridges On a bridge with n > vertical supports, n - bearing reactions can be chosen freely within a reasonable bandwidth This possibility can be used to prestress the superstructure and to distribute the bearing reactions as desired If the bearings are situated (nearly) in a plane we need at least one horizontally fixed and one horizontally moveable bearing The moving direction must not be orthogonal 11 I The layout of bearings to the polar line from the fixed to the moveable bearing If more than two bearings in the horizontal direction are necessary, the basic principle should be that an overall uniform extension, caused by temperature or shrinkage, shall be possible without restraint In general, there are two possibilities for the arrangement of the bearings: a) arrangement in a horizontal position (fig 1.4.1-7) b) arrangement in a position parallel to the road or rail surface (fig 1.4.1-8) I -_ -, a Fig 1.4.1 -7: Horizontal arrangement of the bearings (case a) -(I f= I ,,displaced bridge ( Fig 1.4.1-8: Inclined arrangement ofthe bearings (case b) Case a) has the advantage that only vertical bearing reactions and no permanent horizontal reactions result from vertical loads, but it has the disadvantage that bridges with inclined gradients require a step at the expansion joint due to movements in the superstructure The greater the elongation or shortening, the greater the step required Case b) has the advantage that the slope of the expansion joint is independent of the movement of the bridge The inclination of the surface of support gives the direction of the normal force Besides vertical reaction forces, also horizontal reaction forces result from vertical loads Permanent horizontal actions can lead to a displacement by creep of the concrete and the soil and, thus, to crooked piers 12 Bearings 1.4.2 The layout for different types of bridges For single span girders the layout of the bearings is straightforward One fixed and one moveable bearing is provided on each abutment, all other bearings are just vertical supports, moveable in any horizontal direction For wide bridges the horizontally fixed bearings are located in or near the bridge axis Formerly, the “classical” arrangement of the bearings for a bridge with two main girders consisted of one fixed and one lengthwise moveable bearing at one abutment and one lengthwise moveable and one free bearing at the other abutment (fig 1.4.2-1) This layout has the advantage that longitudinal horizontal forces (braking and traction forces) can be distributed into the two bearings at the abutment, but it has the disadvantage that horizontal forces in the cross direction (wind) and temperature differences cause horizontal restraint forces, provided that bearings have no clearance on the abutments The author prefers the statically determinate system with only one lengthwise restrained bearing at the abutment concerned because the actual clearance of a bearing is not determinable in reality (fig 1.‘4.2-2) LA-:” ++11, %I, _- - - I ;c Fig 1.4.2-1: “Classical” layout Fig 1.4.2-2: Horizontally statically determinate system (better than classical layout) - _ - _ _ - - - - Fig 1.4.2-3: System with separated vertical and horizontal bearings (statically determinate system) 75 2.6 Analysis and design of expansion joints Fatigue design Failure due to fatigue is the main reason for the observed damage Three types of fatigue fractures have been observed (fig 2.6.2-5): 1) Failure of the welded joint between rail and support beam 2) Failure of the support beam ) Failure of the rail Fig.2.6.2-5: Possible cracks due to fatigue For the fatigue design, the stress range is of interest At first it is determined by using the loads given in the standards The horizontal forces due to rolling friction, slope of bridge and acceleration or deceleration must be considered However, they are smaller than the horizontal force due to acceleration and braking The factor consists of three parts: = 5s + R -k E against driving dmcilon gs gR gE Factor due to slope Factor due to rolling friction Factor due to locomotive acceleration/deceleration Q again~tdriving direction Fig.2.6.2-6: Determination of the factors - E [%I tS,kRand cE accelerat,O" 76 Expansion Joints The vertical load acting on an intermediate or edge profile is Fv.k.star The horizontal loads are determined as follows: Intermediate profile: Fh,k.stat = Fv,k,stat Fig.2.6.2-7:Dynamic loading of a rail The contact time t, of the wheel depends on the contact length LR,the velocity v and the width of the profile b b+L, t, =V T half period) The circular frequency is: The impact load is sine-shaped (t, = -; The impact causes a damped sinusoidal vibration (fig 2.6.2-8) For the ultimate limit state analysis the response in the fundamental mode of the system is of interest It is considered by the dynamic value given in the applicable standards Fatigue of material is caused by the stress range Normally, only the first and second amplitude of Fv,k,dyn exceed the constant amplitude fatigue limit 77 2.6 Analysis and design of expansion joints Fig.2.6.2-8: Dynamic loading and response of system Fig.2.6.2-9: Dynamic model The static bending moments in the vertical direction can be determined on the supported continuous beam It depends on the stiffness of the springs if it has to be taken into account or if the springs can be assumed to be rigid In the horizontal direction the consideration of the elastic fixing is essential (fig 2.6.2- 10) Fig.2.6.2-10: Vertical and horizontal static system 78 Expansion Joints It is important to use the dynamic stiffness of the springs because it differs from the static value Both the spring stiffness and the damping coefficient are determined by overrun-tests The frequency fh and the damping coefficient can be determined from the recorded time-deformation curve The spring stiffness Ch,dyn in the model is varied until the lowest natural frequency according to the experiments is observed The logarithmic decrement D of the damping coefficient of a spring-linked expansion joint amounts to approximately 10 % Further possibilities to determine the lowest natural frequency are an analysis by FEM or approximate methods The following method leads to satisfactory solutions The fundamental vibration mode shape of the vertical direction can be described by the static bending line of a continuous girder A sinusoidal loading causes the following bending deflection curve: The following formula leads to the stiffness of the spring: The application of the formulae of the frequency and the rotational frequency leads to the natural frequency of the vertical system: 2= -c (Jj m With known chdyn and equal span widths the frequency fh of the horizontal direction can be determined in the same way But the system is an elastically-supported continuous girder The following figures show some calculated results 79 2.6 Analysis and design of expansion joints F fh fh 450 -8 L 450 L lh=lO@10 m 400 400 350 350 300 300 250 250 1,80 rn 200 2.00 rn 2,20rn 150 100 200 150 100 9 1011 c , ~ ~ - 1[N/ml 0~ Ch,dyn L L 4501 1,40 m Ih= 300.108 m>1m45m 450 rn 4oo 1,80 rn 350 2.00 rn 300 ,1.60 400 l o6 “/mI 10 m 15 m Ih=40@10 m Om I0 rn I0 m 2.20 rn 200 150 100 C h.dyn 1011 “/mI o6 C h.dyn’ 1011 [N/m] Fig.2.6.2- I I : Lowest natural frequencies of an elastically supported continuous girder m Massofrail [kg/m] L Single span [m] Ih Moment of inertia [m4] Ch.dyn Dynamic stiffness of spring [N/m] fh Lowest natural frequency [Hz] The dynamic values cp, and cp2 of the first and second modes of the system are added to the value Acp With an assumed logarithmic damping coefficient of 10 %, the following diagrams give directly the impact factors Acp (fig 2.6.2-12) Either the first or second figure can be used They are suitable for the vertical and horizontal direction 80 Expansion Joints Distance of frequency d The horizontal axis of the diagram (b) contains the natural frequency of the system This version shows the frequency of resonance as the maximum of the graph of the design velocity The values Acp of the resonance frequency are comparatively high Natural system frequencies near the resonance must be avoided at least for the vertical bending The recommended distance from the resonance frequency is also indicated in the diagram With a known design velocity a maximum span of the rails can be determined Longer spans cause higher values Acp, leading to a higher stress range Another disadvantage is an increasing number of stress cycles exceeding the cut-off limit, which means that more than two modes of the system must be considered With the values Acpv and AT,, the dynamic difference moments can be calculated Mv.k.dyn = 'Vv Mv.k.stat Mh.k.dyn = '(Ph ' Mh.k.stat The stress range is determined as follows: 'Ok.rnan.dyn - k dyn + AMh.k.dyn WV wh The design load of an axle is higher than the actual load The nominal stresses should be reduced by the factor fredto get the actual design loads The value of the factor depends on the ratio between design load and loading due to the real traffic situation The determination of the actual traffic situation requires extensive data for the real loads and their frequency (fig 2.6.2-13) Infrequent high loads exert an advantageous influence on the fatigue behaviour (overloading effect) The maximum load for fatigue design must be determined considering the real frequency of the actual traffic loads (e.g there may be load components occurring only in one of a thousand cases) Instead of the nominal stress also the design load could be reduced 81 2.6 Analysis and design of expansion joints In 0.2 0.4 0.6 0.8 7,O A i Amax Fig.2.6.2-13: Example of a typical loading sequence The stress ranges up to the chosen limit are used to determine a constant amplitude stress range that causes the same damage (fig 2.6.2-15) log Ao log U R 4 +=2 MIO , No= Mi0 NL= i W MID log N Fig 2.6.2-14: Fatigue strength curve , R D N= , MIO No- Mi0 NL=100 MIO Ndarn* log N Fig 2.6.2-15: Constant amplitude stress range This value when compared with the stress range A q m a dyn x provides the factor that allows the fatigue analysis with design loads given in the standards to be used For instance, [20] recommends the factor fred= 0.75 for the conditions of traffic in Germany, to be applied to the loads of German Standard DIN 1072 A maximum stress determined in this way is exceeded in only one of a thousand cases The fatigue design has to fulfil the following equation: YFt Partial safety factor of the fatigue loading (yFf= I O) ?/Mf Partial safety factor of fatigue strength (yMf= 1.15) A o ~ 1110 , = a,,,,,.A o ~ Constant ~ ~amplitude ~ ~ stress ~ ~ range for 100 million cycles 82 Expansion Joints Can be ascertained by the analyses of the real sequence using the Palmgren-Miner summation (aloe = 0.4) Fatigue strength for 100 million cycles AOL The construction members of the expansion joint are three-dimensional and compact The fatigue strength A q can be taken from the standard used if it contains a suitable detail category, otherwise tests become necessary The following testing arrangements were recently used with success (fig 2.6.2-16) The required number of tests is normally indicated by the standards Fig.2.6.2-16: Recommended arrangement of the tests The lifetime of a construction can be calculated as a statistical value It is only applicable for the evaluation of that type of construction y - Ndarnage 365 DTLV DAAL p Yd Ndamage DTLV DAAL = P Design life - time in years The number of cycles exceeding the cut-off limit The average of daily lorry traffic in one direction The average number of axles of each lorry The distribution of the DTLV on several lanes p = 1.O in case of one lane p = 0.85 in case of two lanes p = 0.80 in case of three or more lanes 2.6.3 Elastomeric cushionjoint The loads for the ultimate limit state analysis and the reduced loads for the fatigue analysis are determined in the same way as for the seal expansions joints In the vertical direction the analysed element transfers a portion of the wheel load, depending on the zone of influence Horizontal loads are determined from the vertical loads using the factor Intermediate profile: Edge profile: Fh.k.stat Fh.k.stat = = Rv.k.stat ’ Fv.k.~tat 2.6 Analysis and design of expansion joints 83 The horizontal loading of edge profiles and their fixings are analysed considering the complete wheel load Edge profiles and fixings can be analysed in the same way as for multiple seal joints A possible intermediate profile can be treated as a single span beam (fig 2.6.3-1) I ,213 ,113 , ,I13 213 Fig.2.6.3-1: Calculation of the intermediate profile The elastomeric parts of elastomeric cushion joints have to withstand stresses and stress ranges due to traffic loads Their strength can be ascertained by tests The following testing arrangement is recommended Fig.2.6.3-2: Recommended arrangement of the test The specimen is of the same character as the planned construction and has a length of at least 1200 mm The loads are applied through an elastomeric disk of 50 mm thickness which is situated in the middle of the cushion element LR and BR are the dimensions of the load area according to the applicable standard If the width of sample is smaller than LR, only a reduced load acts on the joint construction It can be considered by a smaller disk and a force than P The inclination of P depends on the factor It considers the sliding friction or the roller friction, the slope of the bridge and the locomotive’s acceleration and is different for the ultimate limit and fatigue tests The applied force P has the following value for the ultimate limit test: 84 Expansion Joints Fvk 5tdf Wheel load of the standard For the fatigue test the loads are reduced by the factor fred 'red = fie, P The construction is applicable if experiments prove that the full load P can be supported as a static load, the reduced load Predfor millions of cycles 2.6.4 Cantilever-toothedjoint and rolling leaf joint The Bernoulli-Euler theory of bending gives correct results provided that the height to length ratio of a beam is at least 1/5 Fingers of cantilever-toothed joints are often not within this range If this requirement is satisfied the ultimate load can be calculated easily Otherwise tests become essential The fatigue behaviour must be determined by tests anyway because of the three dimensional character of the connection cantilever / edge element The testing arrangement and the applied loads are the same as for cushion joints (fig 2.6.4-1) Maximum stresses are caused when the joint expansion is maximum Fig.2.6.41 : Recommended arrangement of the test The behaviour of a rolling leaf joint should be checked in the same way In most cases neither the application of the Bernoulli-Euler theory of bending is possible nor the standards contain suitable detail categories for the fatigue design The loads must be placed in the most disadvantageous position 2.7 Installation of expansion joints The design of an expansion joint is performed by determination of the extreme values of the expected movements and the position of installation The installation data depends on the planned construction sequence The expansion joint is adjusted by means of an auxiliary construction For a spring linkage prestressing is necessary (fig 2.7-1) It is recommended to instal the expansion joint in the early morning when the temperature is distributed almost uniformly over the whole bridge 85 2.7 Installation of expansion joints Immediately before the installation the actual temperature of the bridge is measured If it is not within the considered tolerance the adjustment must be corrected After that the expansion joint is flushed and fixed temporarily In the case of a steel bridge it is provisionally bolted or tack-welded The auxiliary construction must be removed immediately After carrying out the final fixing, the protection against corrosion is completed In concrete bridges the expansion joints are provisionally fixed by welding together reinforcement and anchoring The concrete pour should be at least of the same strength as the adjacent material of the superstructure While pouring the concrete the joint construction should be protected by a cover Adjustable auxiliary construction ;a’/ \ / Reinforcement Reinfdcement ’ Fig.2.7-1: Possible auxiliary constructionfor the installation In the case of a steel bridge the date of installing the expansion joints has no influence on the expected range of movement In the case of a concrete bridge or a composite bridge, single unidirectional movements (shortening due to creep and shrinkage) occur These movements begin with the erecting of the construction and stop within some weeks / months / years Creep is caused by compressive stresses, especially due to prestressing The movement due to prestessing forces occurs during the prestressing work The joint construction has to accommodate the movements which occur after the installation Therefore, the dimension and, by this, the costs of a joint construction can be reduced by a late installation The variation of creep and shrinkage is shown in the following figures by means of the coefficient of creep cp(-,t,) and the shrinkage value E,, In various standards, t = years (= 1800 days) to t = 20 years is set equal t o t = m 86 Expansion Joints 500 1000 1500 2000 500 1000 1500 Fig.2.7-3: Variation of creep 2000 Time Id1 Time [dl Fig.2.7-4: Variation of shrinkage The maximum increments of shrinkage and creep occur immediately after completion or after prestressing For example after 100 days (about months), about 50 % of the expected creep deformations and 25 % of the shrinkage deformation have taken place 2.8 Inspection and maintenance Expansion joints should be checked regularly by means of visual inspection The frequency depends on the sensitivity of the construction Before the inspection the joint is cleaned, and cover-plates may need to be removed The check should involve the following items: - Damage of the anticorrosive protection This should be repaired before advanced rust formations appear The new coating must be compatible with the existing one - Visible cracks due to fatigue in the steel members - Damages to the seals The soiled water of the carriageway can lead to the deterioration and corrosion of the bearings, the substructure and possible the linkages - Workability of the linkage If it does not fulfil its function, damage of the seals may result - Obstruction or damage of the drainage system The adjacent carriageway pavement should also be checked A jutting joint construction due to wheelers enhances the impact loading If it is not possible to repair the entire pavement, asphalt ramps should be erected to protect the joints Service-free expansion joints are often demanded by the manufacturers Nevertheless, it is recommended to clean the gaps from grit and silt to protect seals and linkage The drainage should also be cleaned regularly 87 2.9 Replacement of expansion joints 2.9 Replacement of expansion joints The lifetime of an expansion joint should be the same as the lifetime of the carriageway pavement A complete replacement becomes necessary if the steel parts exhibit advanced fatigue damage On steel bridges only the bolted or welded connections are removed A replacement on concrete bridges is more expensive More frequent is the replacement of single members, especially of the elastomer components Seals should be replaceable from the carriageway site Manufacturers offer different systems for easy replacement (fig 2.9-1) Edge or intermediate beam Edge or intermediate beam Grooved dowel Clamping strip ic ,-/' Polychloroprene sealing element Polychloroprene sealing element Fig.2.9-I: Possiblefixings to the seal The gap width must be opened to at least 25 mm In the case of an elastic linkage, smaller widths are possible because the rails can be displaced On the other hand the seals must not be stretched fully Expansion joints for large movements should be accessible from the underside to change members of the linkage like elastomeric springs In the case of a road with several lanes it is desirable to change the seals of the expansion joint in sections It is possible to join the seals by vulcanization on site If a replacement of the rails becomes necessary they can also be joined on site However, the joints should be situated in zones with minimal stress range and must be welded very carefully because of the high fatigue loads 88 Expansion Joints 2.10 References Books about expansion joints for bridges: Lee D.J.: Bridge Bearings and Expansion Joints Second edition by E & FN Spon, London, Glasgow, New York, Tokyo, Melbourne, Madras 1994 Papers: Price, A.R (1982): The service performance of fifty buried type expansionjoints TRRL Report SR 740, Transport and Road Research Laboratory, Crowthorne Price, A.R ( I 983): The performance of nosing type bridge deck expansion joints TRRL Report LR 1071, Transport and Road Research Laboratory Crowthorne Price, A.R (1984): The performance in service of bridge expansionjoints TRRL Report LR 104, Transport and Road Research Laboratory, Crowthorne Department of Transport (1989): Expansion joints for use in highway bridge decks Departmental Standard BD 33/88 Department of Transport (1989): Expansion joints for use in highway bridge decks Departmental Advice Note BA 26/88 Koster W (1969): Expansion Joints in Bridges and Concrete Roads Maclaren and Sons Busch, G.A (1986): A review of design practice and performance of fingerjoints Paper presented to the 2nd World Congress on Joint Sealing and Bearing Systems for Concrete Structures, San Antonio, Texas, September Watson, S.C (1972):A review of past performance and some new considerations in the bridge expansion joint scene Paper presented to regional meetings of the AASHO Committee on Bridges and Structures, Spring Koster W (1986): The principle of elasticity for expansion joints Paper presented to 2nd World Congress on Joint Sealing and Bearing Systems for Concrete Structures, San Antonio, Texas, September [ 101 Lee, D.J (1971): The Theory and Practice of Bearings and Expansion Joints for Bridges, Cement and Concrete Association [ I I ] Demers, C.E and Fisher, J.W., Fatigue Cracking of Steel Bridge Structures, Volume I : A Survey of Localized Cracking in Steel Bridges - 1981 to 1988, FHWA Publication No FHWA-RD-89- 166, McLean, VA, 1990 [ 121 Standard Specifications For Highway Bridges 15th edition, American Association of State Highway and Transportation Officials, Washington, D.C., 1992 [ 131 Tschemmernegg, F., The Design of Modular Expansion Joints, Proceedings of the 3rd World Congress on Joint Sealing and Bearing Systems for Concrete Structures, Toronto, 1991 [14] Dexter, R.J., Kaczinski, M.R., and Fisher, J.W.; Fatigue Testing of Modular Expansion Joints for Bridges, Proceeding of the 1995 IABSE Symposium, Volume 7312, San Francisco, CA, 1995 [ 151 TL/TP-FU 92, Technische Liefer- und Priifvorschriften fur wasserundurchlassige Fahrbahnubergange von Strassen- und Wegbriicken Bonn: Bundesministerium fur Verkehr, Ausg 1992 2.10 References 89 - RVS 15.45, Briickenausriistung - Ubergangskonstruktion Wien: Forschungsgesellschaft fur das Verkehrs- und Strassenwesen, Arbeitsgruppe c>, Arbeitsausschuss >, Ausg Januar 1995 [ 171 Braun, Chr.: Verkehrslastbeanspruchungvon Ubergangskonstruktionen in Strassenbriicken Bauingenieur 67 (l992), P 229-237 [ 181 Tschemmernegg, F (a.0.): Ermudungsnachweis von Fahrbahnubergangen nach ENV-1993-1 Stahlbau (1995), P 202-210 [ 191 Pattis, A.: Dynamische Bemessung von wasserdichten FahrbahnubergangenModulsysteme (Dynamic Design of Waterproof Modular Expansion Joints) Ph.D dissertation Department of Civil Engineering and Architecture, University of Innsbruck, Austria (Dec 1993) [20] Herleitung eines Lastmodells fur den Betriebsfestigkeitsnachweis von StraBenbrucken Forschung Strassenbau und Strassenverkehrstechnik Heft 430, 1984 [2 11 Ramberger, G.: Bearings, expansion joints and hydraulic equipment for bridges, IABSE, IS Kongress-Bericht Copenhagen, 1996 [22] Fisher, J.W., Kaczinski, M.R and Dexter, R.J Field and Laboratory Experience with Expansion Joints IABSE, 15 Kongress-Bericht Copenhagen, 1996 [23] Braun, C.: The Design of Modular Joints for Movements up to 2000 mm IABSE, 15 Kongress-Bericht Copenhagen, 1996 [24] Nielsen, H.B.: The Storebaelt West Bridge Railway Expansion Joints IABSE, 15 Kongress-Bericht Copenhagen, 1996 [25] Crocetti, Roberto: Modular Bridge Expansion Joints - Loads, Dynamic Behaviour and Fatigue Performance Thesis for the degree of Licentiate of Engineering Department of Structural Engineering, Division of Steel and Timber Structures Chalmers University of Technology, 1998 [26] Barnard, C.P., Cuninghame, J.R.: Practical guide to the use of bridge expansion joints Application guide 29, Transport research laboratory, UK 1997 [ 161 Richtlinie ... role of expansion joints Calculation of movements of expansion joints Construction of expansion joints Materials for expansion joints Analysis and design of expansion joints Installation of expansion. .. April [ 1091 Lee, D.J (1 97 1): The Theory and Practice of Bearings and Expanison Joints for Bridges, Cement and Concrete Association [ 101 Buchler, W (1 98 7): Design of Pot Bearings, American Concrete... transfer the horizontal forces only at the abutments The same considerations are suitable also for skewed and curved bridges (fig 1.4.2- 6) Bearings for horizontal forces and guide bearings which transfer