User guide - Masonry Arch Analysis Software
Contents
1. e eee eei eee rese eere r e rese reae ee 23 Salt TYPES OR ANATIYSIS cu geo a eo te A Pete 33 SAT Normal analysis uta e qute tud egets eiectus te date tah ate le 33 842227 Rte adel qe Eee te 33 8 2 THESOLDVER t E tete cete dei A pte ede diede e ET Dp Ru 34 8 3 ANALYSIS eoe ete Veo vue deese e eene 34 8 3 1 Collapse load factor ite retento Reese Darse 34 63 27 No solution fourid 34 8 3 3 Troubleshooting ise Re die ek Bre EE 35 9 SCREEN DISPLAY 8 2 52 52 55 8 e Fono c 36 9 1 1 Anonim 36 9 E2 Current MOUSE POSION ze oe cie eite te trc e ree eee see etie eR eae ORTU EYE TEN E RET Pe ERE EE Ua 36 PNIS EET Wr PEE LEER 36 9 1 4 Magnify displacements ee eee ee ed ere Ra eee tere ete dao dee den 36 9 2 VIEW DIFFERENT LOAD CASES nietos esee senec ee eek e oet eR ee seed p eoo ee eek eoa tu b ende us E Sv E 37 10 1 VIEWING REPORT OUTPUT 38 11 VALIDAT2. which means that only one bridge project file can be open in RING at a given time However several instances of RING can be opened simultaneously if required each of these may contain a separate bridge project file This version imposes the following limits on the number of spans rings blocks etc that can be included in an analysis Item Maximum number Spans 6 Rings in a given span 6 Blocks ina given ring those in supporting left hand pier 160 Load cases 20 Vehicles 20 Vehicles in a given load case 6 Axles in a vehicle 20 User defined fill profile points 20 RING User Guide 3 2 Getting started 2 Installation 2 1 1 Installation from CD e Under most versions of Windows a menu will appear a few seconds after inserting the CD Then simply select Install Software from the menu and you will be guided through the installation process e Ifthe menu does not appear on the Start menu select Run and then enter d autorun exe assuming d is the drive letter associated with your CD drive if this is not the case replace d with the appropriate drive letter 2 1 2 Installation from the RING website e Select the Open this file from its current location option and click OK e Alternatively place the download file in a temporary directory on your computer s hard disk drive say c temp Then execute the file you have downloaded e g on the Start menu select Run a
3. if for example it is known that certain sections of masonry have been stitched together To introduce one or more constraint on the Properties menu point to Advanced and click Constraints This opens the following dialog RING User Guide 31 Advanced Properties 7 2 1 Constraining the movement of blocks in a given ring First scroll down the list to find the block whose movement is to be constrained To prevent all types of relative movement between the selected block and its neighbour to its left below in the case of a pier click on each of the cells in the columns headed 1 2 and 3 Partial constraints can be introduced by only clicking in one or two of these columns Constraints are indicated by Y entries in the table The presence of any type of constraint between blocks in a given ring is also indicated by black squares on the bridge plot RING User Guide 32 4 RING 1 0 bridge XI File Properties Analysis View Help 2 Ap QQ Lue 4 x 50 720 Note For a pier click on heading 1 to constrain rotation about the RHS of the pier and heading 2 to constrain rotation about the LHS of the pier 7 2 2 Constraining the movement of blocks in adjacent rings One or more blocks in a given ring may be fixed to a block in the ring below To do this first scroll down the list to find the block whose movement is to be constrained Then click on the cell in the columns heade
4. 10 3 Project details and revisions Although not necessary in order to conduct an analysis comments current user details and details of the location of the particular bridge being assessed can be specified This information is then saved with the data file and is also included in the report output To enter the details on the Properties menu click Bridge details 31 Bridge details Space is provided for various details and comments including UK railway specific details e g ELR Mileage Stations Properties Project Details Ed Bridge details Revisions Bridge Name MoscarLane ELR Bridge Number gza 7 Mileage O Stations at or between fC Bridge type Stone voussoir arch bridge Comments Last visual assessment carried out 23 11 00 3 2 User details and revisions The name and organisation of the current user can be included by clicking on the Revisions tab and then entering the data RING User Guide 11 Properties Project Details George Hubbard Engineers 1 09 01 2001 11 41 41 Peter Smith 2 18 01 2001 11 43 22 George Hubbard EVE x Each time the user clicks on Save whilst working on a file e g named bridgel rng archive file e g in this case named bridgel arc is automatically updated Details of all revisions made to the file are then shown on the Revision history list e g as shown above It is possible to revert ba
5. 10 1 Viewing report output Following an analysis it is often useful to summarise details of the bridge and of the analyses performed and to then print this out RING does not have a printing capability but will following an analysis output a formatted Rich Text File RTF document file that can be read by all modern word processors To output and then view this file on the View menu click Report output This command automatically creates the RTF file in the same directory as the RING data file currently being worked on and then opens it using your favourite word processor ready for editing printing etc e g Microsoft Word Twin span 1 1tf iof x File Edit view Insert Format Tools Table Window Help 287 sm BAR e O ee E Er RESP E Summary T Bridge name ELR 4 Bridge no Mileage Stations at or between notentered notentered notentered notentered notentered Date of assessment Name of assessor Assessing teal kir Bridge type 234 2001 notentered notentered notentered T Analysis result Critical load factor 9 43 load case 4 m Critical falure mechanism Page 1 at 27 1 ini Coli Rec ove WPH 2 Note i If you do not have a modern Windows word processor installed then the report will be read into Microsoft WordPad However this program has
6. Deor 15 42 2 Intrados shape User defined en E E Hp d ete des 15 42 3 No Of TINGS 8 ses RUN BAG HK BGR BUREN eae See ARG RNA ANGLES EA 16 4 3 JPIER ABUTMENT indere e er ovis ae ABA ce e eee BAe Rawal ue uv we 17 43 1 Height isse desee rede EE ean 17 4 3 2 Thickness essere enr ee etre deae de eee ERE EEEE S eode e ae puede EE reped 17 4 3 3 Thickness at basezt ae edere i tn ES 17 434 Numberofblocks in pier up eee de a e D ERI DRE epe 17 MATERIAL PROPERTIES viscsisessosscsocsessseessonstoosssestenstonsseosssestenssetesessseesteansecssessteustangeseeisestensvencsecsss 18 MASONRY PROPERTIES det eoe etre certet stds atid chia heii e RH CLE td 18 tations 18 3 1 2 Coefficient of friction e cp coit ce eq eta es Dip He Eak 18 23 13 Coefficient of friction tahgential dee i ee eria 18 2 1 4 Gr shingistrength 22 eee ge RR IE RR ai ETE e EUIS 19 5 1 5 Crushing strength Advanced Properties eese eene eene enne nennen 19 5 2 BAGKHILU PROPERTIES ede a ee eR REA 20 IAE senno 21 RING User Guide li 5 22 Limiting fill barrel angle of friction and 5 2 3 Lodd dispersion type iie Pee HI DH eq Hp pet
7. crushing settings Ed Solution convergence tolerance 2 0 1 Maximum number of iterations 20 Automatic selection of solution method convergence parameter parameter Beta fi Livesley method Crisfield method 5 1 5 1 Solution convergence tolerance Specify the required convergence tolerance This value represents the maximum permissible difference between the magnitude of the final calculated load factor and the magnitude of the load factor calculated at the previous iteration 5 1 5 2 Maximum number of iterations Specify the maximum number of iterations to be performed by RING when searching for a converged solution RING User Guide 20 Two alternative approaches to the problem of determining the collapse load factor in the presence of finite masonry strength are available Both methods involve first carrying out an initial analysis in which infinite masonry strength is assumed The area of masonry actually required to support the calculated thrust at every joint is then determined and the effective thickness of the arch is modified accordingly This effective arch is then analysed and the process described above repeated until acceptable convergence is achieved Both methods should normally lead to identical solutions but have different convergence characteristics 5 1 5 3 Livesley solution method In Livesley s method it is assumed that a given hinge in the failure
8. fill barrel angle of friction Specify the limiting backfill arch barrel angle of friction in radians This value is used to calculate an upper limit on the magnitude of the horizontal backfill pressures that can be applied to a given masonry block without causing the strip of backfill on the block to slide Note i The specified angle of friction at the fill barrel interface is only used for the above purpose and is not used to calculate frictional energy dissipation at the backfill arch barrel interface e g for use in the work equation ii The check on the limiting horizontal backfill pressures that can be applied is overridden when user defined horizontal pressures are specified 5 2 3 Load dispersion type 5 2 3 1 Uniform Select this option to specify that the magnitude of the pressure exerted on the back of the arch is to be constant The length of arch assumed to be subject to vertical loading pressures is indicated below RING User Guide 22 wid Tuna 5 2 3 2 Boussinesq Select this option to specify that the magnitude of the pressure exerted on the back of the arch is to be calculated according to the Boussinesq equation Normally a limiting distribution angle will be specified default 7 6 rads because experiments have shown that when arch movements become large e g at failure a cone of soil under the applied load tends to punch through When a limiting distribution angle is specified the magnitudes of
9. limited functionality and portions of the report will not display properly ii The picture displayed in the report document is linked to it rather than embedded within it This means that if you try to copy the report file to another directory or PC when RING User Guide opened again the picture will not be displayed unless you also copy the picture file e g bridgel bmp to the same directory as the report document file 39 RING User Guide 40 11 Validating Results 11 1 Basic checks No modern software can be guaranteed to be entirely free from bugs and all users should check their output as thoroughly as is practicable In addition to comparing output from RING with output from other software if this is possible the following checks are suggested e Does the screen display look sensible If not and if the problem is not merely that magnification of the infinitesimal displacements has distorted the structure then there may be a problem with the model e Try analysing the mirror image of the bridge geometry and loading arrangement currently being studied Clearly the calculated collapse load factor should be nominally the same This check is very useful because the displacements in the mathematical formulation are all defined relative to the left hand support s Hence this check should allow any systematic errors in the implementation of the rigid block method to be identified e Check the View Reveal centreline option to e
10. mechanism forms at the centre of a rectangular stress block This method is reliable and allows converged solutions to be obtained for most types of problem However for most simple problems the Crisfield method requires fewer iterations 5 1 5 4 Crisfield solution method In Crisfield s method it is assumed that a given hinge in the failure mechanism forms just above or below a rectangular stress block Internal energy terms are included in the work equation to account for the fact that rotation at a hinge now involves energy dissipation This method normally leads to rapid convergence except when multi rings and or extremely low strength masonry are present 5 1 5 5 Convergence parameter Beta Particularly for problems involving multi rings it is sometimes found that cycling occurs preventing a converged solution from being obtained Should this happen the user may adjust the convergence parameter This parameter when set below the value of 1 0 has the effect of reducing the effects of changes in the calculated magnitude of the force in the line s of thrust at each iteration 5 1 5 6 Automatic selection of solution method and convergence parameter This is now the default option in RING and is recommended for most situations Note i In general the Livesley method is the most effective method when low masonry crushing strengths are involved However when very low crushing strengths are specified it may be impossible to obtain
11. of all parameters that can be modified is given elsewhere all pages displayed as part of the wizard are also accessible from the Properties menu The New bridge wizard comprises 5 main steps when a single span bridge without abutments is specified in Step 1 additional steps are added if more spans etc are specified 2 3 1 Step 1 Specify the global geometry of the bridge RING User Guide New bridge wizard Step 1 Geometry ooo Click Next gt to proceed to step 2 2 3 2 Step 2 Specify the geometry of span 1 New bridge wizard Step 2 Geometry Segmental m 2900 Click Next gt to proceed to step 3 RING User Guide 2 3 3 Steps Specify the properties of the masonry blocks in the bridge New bridge wizard Step 3 Materials Advanced options Click Next gt to proceed to step 4 2 3 4 Step 4 Specify the properties of the backfill in the bridge New bridge wizard Step 4 Materials Pxortamrat a erre aT 72 J8SSIVESBTESSUTETEBTES 7 RING User Guide Click Next gt to proceed to step 5 2 3 5 Step Specify the type of loading applied to the bridge New bridge wizard Step 5 Loading Cases 1 1kN Single Axle 1250 iaa Gadcascis After completing the New Bridge Wizard click Finish the geometry of your bridge and the loading on it will be displayed on screen RING User Guide 8 4 RING 1 1
12. the abutment block feature is useful for properly modelling the interface between masonry arch and beam spans in a viaduct Whilst the feature can also be used to model standard masonry bridge abutments in this case restraint from the soil behind the abutments is likely to be very important and great care must be taken to model this correctly Refer to the Backfill Properties section for further advice 4 1 4 Spandrel zone details Click Change to alter the current spandrel zone settings indicated on the dialog This will bring up the following new dialog Spandrel zone Type Details E only Height of backing above extrados springers mm m Select fill profile type Horizontal Height of top of fill above span 1 oo intrados springing 2000 User defined Cancel 4 1 4 1 Specify whether the bridge has fill only or has both and masonry backing by clicking on the appropriate image In the latter case the height of backing above the extrados springers must be entered When backing is specified only masonry blocks which lie entirely below the specified backing height are conservatively assumed to be subject to restraint from the backing This restraint is assumed to act in one direction only so as not to artificially prevent an arch from peeling away from backing material In this version of RING masonry backing is modelled by the inclusion of horiz
13. ING RESULTG ccccccsscssccsscscssssscssscsssssssssssssssssssssssssssssssssssssssssssssssssssssssssssccssssees 40 11 1 BASIC CHECKS As ELI IEE ON is lees 40 11 2 COMPARISON WITH EXPERIMENTAL 5 58 1 40 RING User Guide 1 1 Introduction 11 About RING RING is a rapid analysis tool for masonry arch bridges The software is based on the mechanism method of analysis originally pioneered by Heyman and has numerous features many of which are unique including e Single and multi span bridge capability e Automatic identification of the critical failure mode in multi span bridges even if this involves only a single span e Failure modes involving sliding identified if critical e Multiple arch ring capability e Multiple load case facility Automatic detection of passive pressures allowing deep arch and multi span arch problems involving passive pressures to be analysed without difficulty e Facility for modelling the presence of arch backing material e User definable masonry compressive strength e User definable arch and backfill profiles e User definable individual block weights and applied backfill pressures e Original MS DOS version of the software was developed in 1992 description of the rigid block analysis method on which the software is based was published soon afterwards Output has also been correlated against results from full scale
14. M and Wagstaff M The collapse behaviour of multi span brickwork arch bridges The Structural Engineer Vol 75 No 17 pp297 305 1997 5 Gilbert M On the analysis of multi ring brickwork arch bridges 2nd International Arch Bridges Conference Venice pp109 118 1998 6 Page J Masonry Arch Bridges TRL HMSO 1993
15. Version 1 1 for Windows RING User guide O Matthew Gilbert University of Sheffield April 2001 1 RING User Guide i Contents I giseneruronqme T 1 Isl SABOULRING AS ceux EE IEEE RAE UAE LM IAE ALICE su 1 1 2 ABOUT THE AUTHORS EEE EEEE E EET EEA 1 1 3 USING HELP 4 ei noe esce 2 1 4 SOFTWARE SUPPORT eec eve teer ee a 2 1 58 SYSTEM REQUIREMENTS ete rede epe re c sede ee e en ne re ERE OR RD Re 2 156 PROGRAM TEIMITS estere teste eere e eerte ee ere n re tee eret e erre eere ren eue 2 GETTING SFARTED sicisactssessecesssadecessc secensncceccsscsvenegnnedacessesennegessdecsssesdenasdaccsceseesaenesscessessecsenees 3 Dek INSTALLATION e et yep bak pn is 3 DAD Installation from CD oat ise taie detienen iere 3 2 1 2 Installation from the RING website esses eee eene nennen nennen enne enne entren enne 3 2 13 Uninstalling RING renia red Ras eed anie 3 2 27 3STARTINGRING ei eiui 3 2 3 USING THE NEW BRIDGE WIZARD vanar Vened ese t tee e to tede eee et 4 2 9 1 Sep Asie ete eda eR M IO RH CO e MEO Mert tede pts 4 2 3 2 ee ee e e bere drm 5 2 39 97 Step Schenken tote eate eee ee td
16. a solution using either method ii The starting point for both the iterative methods described above is output from an initial analysis in which infinite crushing strength is assumed If a structure is initially found to be geometrically locked e g a very thick or flat arch the masonry is then thinned ready for a second iteration If the structure is after iteration 2 still geometrically locked solution will be obtainable This will be the case even if the specified crushing strength is sufficiently low to allow in practice the formation of a hinged collapse mechanism 5 2 Backfill Properties To edit the backfill properties click on the Backfill tab of the materials dialog RING User Guide 21 Properties Materials x Masonry Backfill Load dispersion Unit weight kN m3 18 Uniform Boussinesq Limiting fill barrel angle of friction rads 0 577 Limiting angle rads 0 577 Horizontal pressure type None Uniform Magnitude kN m2 Classical Earth pressure coefficient Automatic entiation at 7 Position Present Passive pressure zones 7 LHS RHS OK Cancel 5 2 1 Unit weight Specify the unit weight in kN m of the backfill material Note i If you wish to model an arch without fill specify a zero value for the backfill unit weight also specify uniform load dispersion and a limiting dispersion angle of 0 rads 5 2 2 Limiting
17. alysis is performed the box should disappear once a solution has been found 8 3 Analysis results 8 3 1 Collapse load factor found Following an analysis the critical collapse load factor will normally be displayed at the bottom left of the RING window If multiple load cases were specified then this load factor will be the lowest found for all the load cases tried 8 3 2 No solution found It is possible that no mechanism of collapse satisfying all the boundary and geometric compatibility conditions could be found i e the structure is geometrically locked This result will typically occur if the specified arch thickness is large and rigid abutments are specified Alternatively it might be that no solution could be found because the collapse load factor can be reduced without limit without violating the boundary and geometric compatibility constraints This result will typically occur if the arch is the wrong shape in relation to the RING User Guide 35 specified dead loading i e the dead loads alone are sufficient to cause the structure to collapse In both of the above cases a Solution could not be found message will be displayed at the bottom left of the RING window 8 3 3 Troubleshooting After PCx is started RING then waits for a solution file to be written to disk Should the PCx software for some reason terminate prematurely the file will not be written and in these circumstances the user should press the E
18. be fixed in position e For an element positioned above an abutment block the end of the element remote from an arch block is assumed to be fixed to a vertical line drawn from up from the centroid of the top block in the abutment This means that the element will only compress if there is a relative closing movement between the backfill above the abutment block and the arch block to which the element is attached in other words no horizontal backfill pressures need be mobilized if blocks in an arch move say to the left provided the skewback on top RING User Guide 24 of the abutment also slides to the left This approach effectively assumes that there is no additional backfill say to the left of the abutment block this is true for the case of an arch span adjacent to a beam span Note i In this release uniaxial fill elements cannot be fixed to the sides of pier abutment blocks User defined horizontal pressures can still be applied to these blocks if required but because fill elements are not present refer to the section below for information on the possible problems which may arise 5 2 5 2 Unchecking this box causes the uniaxial fill elements to be removed from the analysis Instead the multiple of the calculated horizontal force and the horizontal displacement of the extrados face of each arch block is added to the governing work equation in the analysis Unfortunately with this approach there is no guarantee that the pr
19. bridge tests Unlike many other masonry arch bridge analysis programs no attempt has been made to link the software to a specific assessment or design code of practice These are country specific and quickly become out of date Additionally whilst the integration of code requirements into software can save experienced users valuable time novice users are often uncertain as to which code clauses have and have not been hard coded into the software 1 2 About the authors Matthew Gilbert is currently the John Carr Lecturer in Construction at the University of Sheffield He is a Chartered Civil Engineer with more than 10 years involvement in masonry arch bridge research He originally developed an MS DOS version of the RING software in 1992 93 as a tool to interpret the results from the full scale model bridge tests that were being conducted at the time it had been found that the behaviour of bridges containing multiple brickwork rings could not be modelled adequately using available software He also realised that because of the general formulation of the rigid block method of analysis used by RING the method could also be successfully applied to multi span masonry arch bridges Anthony Sollis assisted with the development of the 32bit Windows version of the software He recently graduated from the University of Sheffield with a first class honours degree and is currently employed as a graduate engineer at W S Atkins Epsom UK RING User Gui
20. bridgel File Properties Analysis View Help 65 QQ Loadcael 2420 y 3310 Note i The New Bridge Wizard does not permit more than a single load case to be specified If several loading cases are required click Finish to exit the New Bridge Wizard then on the Properties menu click Loading then add further load cases as necessary 2 4 Performing an analysis To perform the analysis on the Analysis menu click Analyse Alternatively this command can be accessed via a button on the toolbar and the keyboard shortcut for the command is Ctrl A The collapse mechanism and associated collapse load factor will be displayed after a second or two the processing time depends on the complexity of the problem specified and on the speed of the PC being used RING User Guide 4 RING 1 1 bridgel IDE Xx File Properties Analysis View Help QQ Loue 1100 y 3320 2 5 Output from analysis On the View menu click Report output This command automatically loads a report that includes details of the bridge and analysis into your favourite word processor It is then possible to save edit and or print this file in the usual way Note i If you do not have a modern Windows word processor installed then the report will be read into Microsoft WordPad However this program has limited functionality and portions of the report will not display properly RING User Guide
21. ck to a previous revision of a file by highlighting the appropriate entry on the revision list and by then clicking Revert To RING User Guide 12 4 Bridge geometry To edit the bridge geometry on the Properties menu click Geometry Alternatively the command may be accessed via the toolbar and the keyboard shortcut for the command is Ctrl G 4 1 Global Geometry Properties Geometry Ed Global Span 1 Number of spans 1 Width of bridge to be analyzed mm fi 000 End abutment blocks Abut 1 Left Hand Side Abut 2 Right Hand Side Spandrel zone details Spandrel void Backfill only Backfill profile Horizontal 4 1 1 Number of spans Enter the number of spans in the bridge under consideration or the number of spans that are to be modelled 4 1 2 Width of bridge to be analyzed Enter the width of the bridge to be analysed in mm Note i When the total bridge width is significantly greater than the width of any applied loading the width of bridge to be analyzed should normally conservatively be taken as the vehicle width plus if necessary some amount to account for transverse dispersion effects 4 1 3 End abutment blocks Check the Abut 1 and or the Abut 2 boxes if you wish to include masonry bridge abutments in an analysis If these are not included the first and last spans will be assumed to be founded on rigid springers RING User Guide 13 Note i At present
22. ckfill and d is the depth of fill at the point where the horizontal pressure is being calculated Note i Small changes to the specified uniform horizontal pressure K value can lead to large changes in the computed collapse load Hence care must be exercised when selecting this value ii The horizontal backfill pressures defined above may be reduced by the program if these are sufficiently high to cause relative sliding between the backfill and the arch barrel See the Limiting fill barrel angle of friction section values of the backfill pressures calculated here can subsequently be modified if required See the Editing weights pressures section 5 2 5 Automatic identification of passive zones 5 2 5 1 On Checking this box causes uniaxial fill elements to be included in the analysis These elements are positioned horizontally in the spandrel void area s Elements are initially placed in contact with every block in the arch extrados The elements exhibit the following characteristics e The elements are constrained to either stay the same length or to compress e The elements exhibit a rigid plastic response in compression i e they compress at a constant force This force is equal in magnitude to the specified fill pressure multiplied by the vertical height of the extrados face of an arch block e For an element positioned above a rigid abutment the end of the element remote from an arch block is assumed to
23. d RING User Guide 33 8 Performing an analysis To perform the analysis on the Analysis menu click Analyse Alternatively this command can be accessed via a button on the toolbar and the keyboard shortcut for the command is Ctrl A 8 1 Types of analysis 8 1 1 Normal analysis When a single load case is set up the load factor that would when applied to the specified live loading cause the bridge to collapse is calculated and displayed When multiple load cases are set up the collapse load factor associated with each is calculated in turn However because the problem geometric compatibility constraints only need to be set up once the total CPU time required for two load cases say is rather less than twice that required for one load case 8 1 2 Iterative analysis When finite masonry crushing strength is specified an iterative analysis is performed In the first iteration infinite crushing strength is assumed The calculated magnitude of the force in the line of thrust and the specified crushing strength is then be used to alter the effective positions of the intrados and extrados ready for the next analysis This process is repeated until the collapse load factors calculated at successive iterations are deemed to be sufficiently close Information on the progress of the analysis is given in the following dialog RING iterative analysis report x ITERATION HISTORY lt Crisfield method No Load factor Crush streng
24. de 2 1 3 Using Help The software includes an online help facility which is largely based on this guide Pressing F1 at any time will activate the help system 1 4 Software support As RING is currently available free of charge it is not possible to offer free technical support to users However reports of bugs and constructive comments and suggestions are essential in order for the software to be improved in the future and are most welcome Please direct these to m gilbert O sheffield ac uk with RING COMMENTS as the subject Please also regularly check the RING website www shef ac uk ring for information on bug fixes and other program enhancements It will often be possible to respond to urgent requests for technical assistance but standard University of Sheffield consultancy rates will normally be charged Please send details of your problem to m gilbert sheffield ac uk with RING URGENT as the subject Where possible consultancy fees obtained in this way will be used to support further development of the RING software 1 5 System requirements RING requires a 32bit Windows operating system to run i e Windows 95 98 Me or NT4 2000 It is recommended that the software is run on a system with a Pentium II class processor or better and 64Mb RAM note that the online HTML based help facility may not function correctly with early versions of Windows 95 1 6 Program limits The program uses a Single Document Interface
25. dmi 6 eie ta auch md m ad 6 2 309 SLOP Di des deret 7 2 4 PERFORMING AN ANALYSIS ccccccccssssseeccceccecaueeeccceeeecaueeeececeeeeauuseeeeeceseeasaeeeeeeeeeeesuueaesceeesseeaaaaeeeeeeeeea 8 2 5 OUTPUT FROM ANALYSIS ccccccccccececececeeceeeeeeeceeeeeececeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeees 9 PROJECT DETAILS AND REVISIONS sssscccsscicoscecsscccecseScosessscsaccssessesnacdcsscssseseonsaceesecssseSeoncest cssusees 10 31 BRIDGEDETAIES eret P teet de dee tee ue Ne etre 10 3 2 USER DETAILS AND REVISIONS ceeeeeeeeeeeeene nenne nennen nnn eese essai rnt n nne ssssska eins sesss essa aene esses saa annees 10 BRIDGE GEOMETRY LR 12 4 1 5 12 qd LL Number Of SPanss 2 send a estet easi Aaa wees 12 412 Width of bridge to be analyzed eee dette de ende 12 413 Enda butmenkblocks nue RR eee ed Biv eeez te 12 41 4 Spandrel zone details ee Rt dee enden ese ree ete odere e ed 13 2 2 SPAN GEOMETRY E ode tender ere Ade ke doe ied A uec eve E ue S 15 42 Intrados shape Segmental deo dere det
26. e the height of the top of the fill relative to the bridge datum point should be specified The RING datum point is assumed to be the left hand intrados springing of span 1 In the latter case a list of x and y co ordinates to adequately describe the surface of the fill should be specified once again all points are relative to the bridge datum point e g Spandrel zone Type Details Fill with masonry backing Height of backing above extrados springers mm 000 Select fill profile type Horizontal x co ord mm co ord mm 6 User defined Note i User defined fill profiles are in this version of RING formed from a series of straight lines which intersect the points specified RING User Guide 15 4 2 Span geometry To edit the geometry of span 1 say click on the Span 1 tab to obtain the following display Properties Geometry Span2 0 Segmental gt 500 1250 Select Segmental or User Defined to define the intrados shape of the span being considered 4 2 1 Intrados shape Segmental 4 2 1 1 Span Enter the span of the arch in mm 4 2 1 2 Rise Enter the rise of the arch in mm 4 2 2 Intrados shape User defined 4 2 2 1 No of points Enter the number of points that are to be entered in order to adequately describe the shape of the arch 4 2 22 x co ord point n Enter the x co ordinate of a point n on the i
27. e centre of the updated display 9 1 4 Magnify displacements Following an analysis the failure mechanism is indicated by the positions of hinges and by deformation of the structure It is sometimes useful perhaps to clarify the mechanism of RING User Guide 37 collapse to deform the bridge more To do this on the View menu click Magnify displacements and then move the slider as appropriate Note i This option is only available after an analysis has been performed 9 1 4 1 Report output Refer to the Report output section for further details of the report output that can be produced using RING 9 1 4 2 Iterative analysis report This option re displays details of the progress of the iterative analysis only available if finite crushing strength was specified Part or all of these details can be copied onto the Windows clipboard ready for transferring to other applications by highlighting the required sections with the mouse and by then pressing CTRL C 9 1 4 3 Copy current bridge screen display to Windows clipboard Right click on the screen display to be captured and then paste the bitmap image into the application of your choice 9 2 View different load cases To view a particular load case and if an analysis has just been performed also the associated collapse load factor select this using the Up Down arrows adjacent to the load case cell in the main RING toolbar RING User Guide 38 10 Report output
28. e computed factor is an upper bound on the exact load factor though this upper bound often coincides with the exact value Refer to reference 2 for more details 5 1 3 Coefficient of friction tangential Specify the coefficient of friction between adjacent rings RING User Guide 19 Note i For problems involving several rings it has been found that the modelling of friction by assuming that separation accompanies relative sliding between rings often leads to reasonable estimates of bridge strength e g computed strengths often found to agree well with Bolton arch and arch bridge strengths refer to reference 3 However it should be borne in mind that strictly speaking the computed factor is an upper bound on the exact load factor 5 1 4 Crushing strength Specify whether or not the masonry is to be assumed to have infinite compressive crushing strength If not specify the value of the crushing strength N mm Note i When crushing strength is included in the analysis the problem becomes non linear and several iterations will normally be required before a converged solution is obtained This means that the computational effort required to obtain a solution is increased significantly 5 1 5 Crushing strength Advanced Properties When a finite crushing strength is specified an iterative solution procedure is required Clicking on Advanced Properties opens the following dialog Advanced masonry
29. ere 5 24 Horizontal pressure type ie tree Lr Ur edite 5 2 5 Automatic identification of passive zones 6 1 DEFINING VEHICLE PROPERTIES 2 25 6 1l Ediingvehicle properties uic iade eene 26 6 1 2 Defining a new vehicle using RING eese eene nnne nennen nennen enne nennen 26 6 1 3 Defining a new vehicle using properties saved in a file iva 6 2 DEFINING LOAD CASES coeleste 27 6 2 1 Adding vehicles to an existing load case eese eene nennen 27 6 2 2 Adding Load c ses isnt pure tet ug un ute pu eed eg ee 28 6 23 Deleting a load i wae eed eec pedet uet a eiue poe ate 29 6 3 VIEWING EOADCASES 5 e ibt eM ULM dura 29 7 MODIFYING STANDARD 8 4 4 4 30 Todt EDITING WEIGHTS PRESSURES 3 eee ecce o co decet oco doses eee Poe eeu dee eode ve esee e oes eve Dee neve 30 7 2 CONSTRAINING BLOCK MOVEMENTS ee cos cese ee eee gt eee epe ee see soe es de ete pee ee aee ee De eget vue 30 7 2 1 Constraining the movement of blocks in a given 31 7 2 2 Constraining the movement of blocks in adjacent rings esee 32 8 PERFORMING 515 020 0202 5
30. essures will be mobilized in the correct sense i e there is no stipulation that the pressures can only be mobilized when the arch moves into the fill Thus when the uniaxial fill elements are not present the user should specify in advance of the analysis in which zones horizontal fill pressures are to be mobilized For example for a single span arch which is to be loaded to the left of the crown fill pressures should be specified only to act on the right hand side RHS of the arch However this approach is likely to be problematic in many cases e g for multi spans multiple load case analyses deep arches etc Fortunately for the user if pressures are not mobilized in the correct sense the computed load factor will be a lower bound on the exact load factor Note Some additional computational effort is required when fill elements are included in the analysis Thus in certain situations e g when it is obvious in advance that fill pressures will be mobilized in a given zone there may be justification for switching off the automatic detection of fill pressures RING User Guide 25 6 Applied loading In RING a library of loading vehicles can be set up and then used to form a load case Multiple load cases can rapidly be set up by repositioning an existing load case at regular intervals across a bridge 6 1 Defining vehicle properties On the Properties menu click Loading to obtain the following dialog Properties Loading Case
31. g dialog Add new loadcase s Ed What do you want to do Set up an entirely new load case Proceed Create new load case s by incrementing positions of loads in loadcase 1 Use 1 increments of 300 mm Proceed In most cases it is easiest to create one or more new load cases by incrementing the positions of an existing load case In this case select the existing load case no and the number of and spacing between the new load cases to be generated Then click Proceed in frame B RING User Guide 29 Alternatively a single new load case can be set up manually by clicking Proceed in frame A 6 2 3 Deleting a load case Click on the tab of the load case number to be deleted e g LC2 shown below and then click the Delete Load case button Properties Loading Cases x New Vehicle New Vehicle 2 Vehicle Library Add Loadcase s Delete Loadcase Note i When a load case is deleted all load cases with numbers greater than that of the one being deleted are renumbered load case no load case no 1 ii It is not possible to delete load case no 1 LC1 if that is the only load case in the analysis 6 3 Viewing load cases To view a particular load case and if an analysis has just been performed also the associated collapse load factor select this using the Up Down arrows adjacent to the load case cell in the main RING toolbar RING User Guide 30 7 Modifying standard p
32. he height of the pier abutment to the arch springer s in mm 4 3 2 Thickness at top Enter the thickness of the pier abutment at the top in mm 4 3 3 Thickness at base Enter the thickness of the pier abutment at the base in mm 4 3 4 Number of blocks in pier Enter the number of units in the pier abutment RING User Guide 18 5 Material properties To edit the material properties on the Properties menu click Materials Alternatively the command may be accessed via the toolbar and the keyboard shortcut for the command is Ctrl M This will open the following dialog Properties Materials Ed Masonry Backfil Unit weight kN m3 18 Coefficient of friction radial 0 6 Coefficient of friction tangential o Crushing strength Infinite User specified Crushing strength 10 dvanced options 5 1 Masonry Properties 5 1 1 Unit weight Specify the unit weight in kN m of all masonry in the bridge i e arches and piers 5 1 2 Coefficient of friction radial Specify the coefficient of friction between adjacent masonry units in a given ring Note i RING models friction by assuming that sliding between adjacent blocks is accompanied by separation so called dilatant friction or plastic shearing For most arch problems this assumption has been found not to affect the computed load factor However it should be borne in mind that strictly speaking th
33. nd then enter c temp ring1xx_install exe where ring xx_install exe is the name of the file you have downloaded e You will now be guided through the remainder of the installation process 2 1 3 Uninstalling RING Should you at any time wish to remove RING on the Start menu point to Settings and click Control Panel Now click on the Add Remove Programs icon and double click on RING in the list of registered programs displayed 2 2 Starting RING To start RING on the Start menu point to Programs and click RING A few seconds after starting RING the following dialog should appear Welcome to RING 588804 874444 LaL oe eo i pue 4 OK Cancel RING User Guide 4 The easiest way to proceed is probably to click OK the New bridge wizard will then start Alternatively select Open an existing bridge project to load one of the sample projects from the Samples subdirectory Look in E Samples Twin span 1 1ng ei Twin span 2 mg File name Twin span 1 mg Files of type RING data files rma Cancel In this latter case select one of the sample files and click Open Refer to the Performing an analysis section for instructions on how to now perform an analysis on the selected sample bridge 2 3 Using the New bridge wizard The New bridge wizard guides the user through the process of defining the bridge geometry materials and applied loading Further explanation
34. nsure that the plotted line is continuous at bridge piers e Check some of the calculated block weights and pressures against hand calculations these can be viewed via the Properties Advanced Edit weights pressures submenu item Finally users are advised to regularly check the RING website www shef ac uk ring for information on bugs fixes and other program enhancements 11 2 Comparison with experimental results A number of full scale bridge tests have been conducted over the last two decades or so in the Although in some cases insufficient information was available to analysts to facilitate accurate modelling the tests were undoubtedly very useful It might be productive for new users of RING to attempt to model one or more of the full scale model bridge tests in order to obtain a feel for the relative importance of the input parameters Additionally it is anticipated that sample comparisons between RING analysis results and full scale bridge test results will be published on the RING web site in early 2001 RING User Guide 41 12 References 1 Heyman J The masonry arch Ellis Horwood Chichester 1982 2 Gilbert M and Melbourne C Rigid block analysis of masonry structures C The Structural Engineer Vol 72 No 21 pp356 361 1994 3 Melbourne C and Gilbert M The behaviour of multi ring brickwork arch bridges The Structural Engineer Vol 73 No 3 pp39 47 1995 4 Melbourne C Gilbert
35. ntrados in mm 4 2 2 3 y co ord point n Enter the y co ordinate of a point n on the intrados in mm RING User Guide 16 Properties Geometry x Global Span Pier1 Span2 Abut 2 Intrados shape User defined No of points 5 No of rings 2 No of units Thickness mm 83 107 5 85 107 5 Note i The positions of all points should be measured relative to point 1 which should have co ordinates 0 0 Subsequent points should be entered in order of increasing x distance ii For a user defined arch the shape is formed from a series of segments of circles as was often the practice during the construction of nominally elliptical and parabolic arches 4 2 3 No of rings Enter the number of rings in the span being considered 4 2 3 1 of units ring i Enter the number of masonry units in the ring 4 2 3 2 Thickness ring i Enter the ring thickness in mm Note i A multi ring analysis is considerably more computationally expensive than a single ring analysis ii Reasonable results can normally be obtained by modelling only a proportion of the actual physical units in a given ring this often reduces run times considerably with only moderate loss in accuracy However it should be noted that collapse load predictions obtained using this strategy may be slightly non conservative RING User Guide 17 4 3 Pier Abutment Properties Geometry 4 3 1 Height Enter t
36. ontal fill elements in the analysis These elements are positioned horizontally in the spandrel void area s and are initially in contact with every block below the specified backing height The use of fill elements in the analysis to represent backing means that e Vertical fill pressures from fill self weight and or the applied loading are not affected by the presence of backing RING User Guide 14 e The automatic identification of passive zones option must be selected when backing is specified this is the default setting in RING e The precise areas where backing is present can be edited using the Editing weights pressures feature e The crushing strength of the backing material can also be modified using the Editing weights pressures feature default value 5000 kN m Note i The backing idealization described above effectively assumes that relative sliding between the arch and backing does not occur Thus backing should only be safely included where the angle between the line drawn tangentially to the arch extrados and the horizontal is suitably large ii The unit weight of the backing is assumed to be the same as that of the fill material If this assumption is grossly inaccurate the vertical pressures applied to the back of the arch can be edited using the Editing weights pressures feature 4 1 4 2 Fill profile type The fill profile type may be selected as either Horizontal or User defined In the former cas
37. osition width mm Intensity 0 250 100 1000 Add Vehicle Import Vehicle OK 6 1 3 Defining a new vehicle using properties saved in a file Click on Import Vehicle to import details of a vehicle previously saved in a comma separated variable csv file This type of file can easily be exported from a spreadsheet or can be created using a text editor such as Windows Notepad although make sure the file has a csv rather than a txt extension The following Notepad text file would generate the same library entry as was entered manually in the dialog above New Vehicle 0 250 100 1000 250 100 Using a spreadsheet the same data could have been entered as follows and then saved as a csv file prior to being read in by RING A ew Vehicle 1 2 0 3 1000 6 2 Defining load cases 6 2 1 Adding vehicles to an existing load case In RING several vehicles can be used to form a load case e g RING User Guide 28 Properties Loading Cases x Lc1 No of vehicles in this load case 2 New Vehicle New Vehicle 2 Vehicle Library Add Loadcase s Delete Loadcase OK Cancel Note i The vehicle positions specified are relative to the assumed bridge datum point which is the left hand intrados springing of span 1 6 2 2 Adding Load cases To add further Load cases click on Add Load case s to obtain the followin
38. roperties 7 1 Editing weights pressures It is sometimes necessary to change the weights of individual blocks or the backfill pressures applied to them from the automatically calculated values For example a bridge pier may in reality have voids within it that locally reduce the weight of notional pier blocks In practice this will slightly reduce the overturning resistance of the pier and hence it should be included in the analysis To modify a block weight or applied pressure on the Properties menu point to Advanced and click Edit block weights pressures This opens the following dialog Advanced Properties x Weights Pressures Span Ring Block pv kN m2 ph KN m2 4 Span 1 1 1 0 58 32 583 0 Span 1 1 2 0 58 30 434 0 5 1 1 2 0 58 28 369 0 Span 1 1 4 0 58 26 393 0 Span 1 1 5 0 58 24 51 0 Span 1 1 6 0 58 22 725 0 Span 1 1 0 58 21 041 0 Span 1 1 8 0 58 19 461 0 Span 1 1 3 0 58 17 989 Key w block weight pv vertical fill pies ph horiz fill pres Reset Block weights and the horizontal and vertical pressures applied to the mid point of the extrados surface of a given block can then be modified as required When a given value is modified the new value is highlighted in red All values can be reset to their original values by clicking the Reset button 7 22 Constraining block movements The relative movements between adjacent blocks can be constrained if required This is useful
39. s 1kN Single Axle 1250 To view and or edit the properties of the vehicles in the model click on the Vehicle Library button to obtain the Vehicle Library dialog RING User Guide 26 Vehicle Library Library entry for No of axles 1 Y Position mm Width mm Intensity 0 300 1 Add Vehicle Import Vehicle OK 6 1 1 Editing vehicle properties The number position width loaded length and intensity force exerted of axles in the existing vehicle can now be changed Use the drop down box highlighted above to change the current vehicle if several vehicles have been entered Note i It is usually sensible to position the first axle in a vehicle at a position of Omm Axles in the vehicle to the right of this axle are then indicated by positive distances entered in the table In the case of an unsymmetrical bridge crossed by an unsymmetrical vehicle the user may wish to set up two entries in the library to represent the same vehicle one each for when the vehicle is crossing the bridge from right to left and from left to right 6 1 2 Defining a new vehicle using RING To define a completely new vehicle click on the Add vehicle button and enter the name of the vehicle to be added Subsequently the details of the vehicle can be added to the Vehicle Library e g RING User Guide 27 Vehicle Library Library entry for New Vehicle No of axles 2 un P
40. sc key to abort the analysis and return control to the user RING User Guide 36 9 Screen display options 91 General 9 1 1 Scrollbars Vertical and horizontal scrollbars allow the display area to be shifted in the vertical and horizontal sense respectively 9 1 2 Current mouse position The position of the mouse is shown on the top right hand corner of the screen This may be useful for determining the global position of various parts of a bridge the datum for all bridges is the left hand springing of span 1 9 1 3 View options Several options are accessible via the View menu 9 1 3 1 Show extrados pressures Turns on off the display of the extrados pressures This comes into effect next time the bridge is redrawn 9 1 3 2 Reveal arch centreline Turns on off the display of the arch amp pier centreline This comes into effect next time the bridge is redrawn 9 1 3 3 Reveal ring constraints Turns on off the display of lines which represent the geometric constraints between adjacent rings This option comes into effect next time the bridge is redrawn 9 1 3 4 Show thrustline Turns on off the display of the thrustline This comes into effect next time the bridge is redrawn 9 1 3 5 Zoom in out The user can zoom in or out by first clicking on the appropriate menu item or by clicking on one of the magnifying glass icons on the toolbar and by then clicking on the area of the screen which is to be th
41. th 1 Infinite 2 1 3 3 4 5 1 1 1 1 Note i When multiple load cases are also specified an iterative analysis is only carried out on the load case identified as being most critical following the initial infinite crushing strength analysis This significantly reduces the computational effort required to obtain a solution and will normally result in a close estimate of the collapse load factor being obtained RING User Guide 34 8 2 The solver A solver is required to find the minimum possible collapse load factor and associated collapse mechanism The collapse mechanism must satisfy all boundary and geometrical compatibility constraints these are set up for a particular problem by RING The solver distributed with this version of RING is PCx 1 1 a 32bit interior point linear programming program developed at the University of Chicago During the course of an analysis RING starts the solver automatically Information on the progress being made towards a solution is displayed in a black console window T PX IST or Swindows TEMPStemp spe columns 1 pass 1 pass When a solution has been obtained or when several load cases are involved when several solutions have been obtained the console window should disappear If this doe not occur click on the icon at the top left of the console window and select Properties On the first page of the dialog check the box Close on exit and then click OK Next time an an
42. the pressures calculated using the Boussinesq equation are scaled up so that that the integral of the vertical pressures acting on a length of arch equals the magnitude of the applied force The length of arch assumed to be subject to vertical loading pressures is indicated below 8 8 d varies Note i Use the Uniform option to comply with the requirements of some assessment codes Note however that the Boussinesq option is likely to provide a more realistic representation of the actual distribution of fill pressures ii RING is a 2 dimensional analysis program Transverse dispersion through the fill is therefore not considered in the program RING User Guide 23 5 2 4 Horizontal pressure type 5 2 4 1 None Select this option to conservatively assume that no horizontal passive backfill pressures will be mobilized when the arch sways into the backfill 5 2 4 2 Uniform Select this option to specify that horizontal backfill pressures of specified constant magnitude will be mobilized when the arch sways into the backfill 5 2 4 3 Classical Select this option to specify that the magnitude of the horizontal backfill pressure exerted on a given masonry block will be proportional to the vertical self weight pressure exerted by the backfill material i e the horizontal pressure exerted will be of magnitude K G d where K is the coefficient of lateral earth pressure specified by the user G is the unit weight of the ba
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