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Bridge Design Balanced Cantilever Bridge FEA/SSD/SOFiPLUS Version 2014 SOFiSTiK AG 2014 Bridge Design Tutorial This manual is protected by copyright laws No part of it may be translated, copied or reproduced, in any form or by any means, without written permission from SOFiSTiK AG SOFiSTiK reserves the right to modify or to release new editions of this manual The manual and the program have been thoroughly checked for errors However, SOFiSTiK does not claim that either one is completely error free Errors and omissions are corrected as soon as they are detected The user of the program is solely responsible for the applications We strongly encourage the user to test the correctness of all calculations at least by random sampling Bridge Design Tutorial Table of Contents 1  Project Description 4  1.1  2  Geometry 4  Model: 5  2.1  SOFiPLUS: 5  2.2  Cross Section 7  2.3  Load Case Manager 10  2.4  Cross Section - Reinforcement 11  3  Pre-stressing: 12  3.1  Tendon generation inside SOFiPLUS 12  3.2  Tendon Generation with “User Task”: 14  4  Construction Stage Manager: 15  4.1  Stages: 15  4.2  Groups: 16  4.3  Loads: 17  4.4  Control Parameters: 17  5  Traffic loads: 19  6  Combinations, design – CSM_DESI: 24  7  Additional definitions: 27  Content Bridge Design Tutorial Project Description This tutorial hand out requires basic SOFiSTiK knowledge and is supposed to be used within a training session run by a SOFiSTiK trainer Inside this tutorial we guide you through the following bridge project The analytical model of the bridge consists of quadrilateral elements QUAD’s (superstructure) and beam elements (columns): For a better understanding and reproducing, we split up the data files according to the different chapters This enables you to start in the middle of the Tutorial if necessary The idea of this tutorial is to guide you through a simple RC bridge project and introduce the general workflow showing the necessary program tools and functions All steps like modelling, loading, traffic, combinations etc are simplified If there are any hints of new tasks that have to be modified manually (new tasks named “Text Editor (Teddy)”) you find further information’s directly in those tasks Please open data files related to the chapter 1.1 Geometry Bridge Geometry: Spans [m]: - 10 - 30 - 60 - 30 Stations [m]: 10 40 - 10 100 130 140 Bridge Materials: Concrete bridge deck: C 40/50 Concrete columns: C 40/50 Reinforcement steel: B 500 Balanced Cantilever Bridge Bridge Design Tutorial Model: Start SSD, new project, EN1992-2004, Road Bridges, 3D FEA Check material (C40/50, B500) Open SOFiPLUS(-X) to define: - 2.1 Cross section(s) System axis Variables Beam elements Supports Load actions (G_1, G_2, P, C, L, F) Loading cases for self weight (test), Settlement SOFiPLUS: Create a new project axis called “sys”, horizontal alignment as straight line New variable for section height: “H” (units [mm]!): Balanced Cantilever Bridge Bridge Design Tutorial Placements are so called “points of interest” along axis Here: we use “supports” and “construction joints” Hint: use “station offset” for quicker definitions Support axis @: 0, 10, 40, 100, 130, 140 Construction point/joints @: Balanced Cantilever Bridge 10 - 40 incr 3.0m 40- 100 incr 3.0m 100- 140 incr 3.0m Bridge Design Tutorial 2.2 Cross Section New cross section called “box” used for the main girder: assign variable “H” to section Draw outer section shape, define boundary, draw inner boundary, define opening, define stress points top and bottom, and assign variable “H” to corners of section: 12.0m 0.25m 0.40m 2,80 / 0.15 m 0.30m 6.40m Close and calculate the section to also see CG and SC Create new rectangular section for piers: Balanced Cantilever Bridge Bridge Design Tutorial Create a new structural line and assign section to axis (segment on bridge axis – see right mouse click menu): Define meshing options: “mesh as one element” for balanced cantilever parts, automatic meshing for columns and side span meshing The support placements are displayed as grey rectangle Double-click on placements for support axis to work on local section at this specific placement: bearings, columns, eccentric connections (constraints): Balanced Cantilever Bridge Bridge Design Tutorial Note: group numbers for beam and spring elements must be defined correctly to match with construction sequence: Balanced Cantilever Bridge Bridge Design Tutorial 2.3 Load Case Manager Go to LoadManager to define “Actions” and “ Loadcases”: Balanced Cantilever Bridge 10 Bridge Design Tutorial Calculate all loading cases incl PT., check behavior in animator There are usually many different tendons to define, in this case we recommend making use of copy/past/modify that is much easier in text file input than in graphic input Balanced Cantilever Bridge 13 Bridge Design Tutorial 3.2 Tendon Generation with “User Task”: With right mouse click on the task we can view input in text format Next step is to complete the tendons, done via text input “TEDDY” See input in text files We use F1 for help as well as we use variable definitions for having flexibility for number of tendons, geometry, etc.: We also introduce a few variables for “number of tendons per stage”, segment lengths, distances etc These variables will make it easier to optimize the PT There are three TEDDY tasks for PT in the cantilevers, PT for the continuity tendons and for the side spans After calculating the tendons, we can view reports, animator, and also the PT loading cases the loadcases for the tendons will not be used for the construction stages These are “storage cases” where the PT loading info is generated and stored for later use Note: important input also predetermining the stage definitions in the following chapter are the ones for    jacking the tendon … in which stage (ICS1)? grouting the tendon … in which stage (ICS2)? removing the tendon … in which stage (ICS3)? Balanced Cantilever Bridge 14 Bridge Design Tutorial Construction Stage Manager: Before going into the stage definitions some things were added to the project: - A traveler load (Load manager and Loadcases 19, 29, 39,….) for each stage the pt geometry is extended: now we also see a horizontal offset A new variable is introduced as well Insert new task for CSM, Double click 4.1 Stages: The numbering sequence (allow gaps for later changes!) as well as the titles are user defined The TYPE has to be set as such that the program knows what it has to All events have to be aligned along the time axis Only Creep + Shrinkage allow moving on the time axis Also important is the link between tendon and stages Schematic construction sequence: Stage 21 Stage 41 Stage 31 Stage 11 First group activation (age 7), nd group Stages activation for activation rd group PT, th group Stages activation for for (age 7), traveler (age 7), traveler (age 7), Self weight new and Self weight new and Self weight PT, traveler Self weight to to applied be PT, Stages be to be l to be applied applied applied Creep+shrinkage 14 days T0 Creep+shrinkage 14 days Creep+shrinkage 14 days T42 T28 T14 Time axis Elements of stage 11 are Elements of stage 11 are from zero 7+14=21days old 7+14+14=35days old Elements of stage 11 are 7+14+14+14=49days old to oo Elements of stage 21 are Elements of stage 21 are 7+14=21days old 7+14+14=35days old Elements of stage 31 are 7+14=21days old We also define a certain stage for which we want the precamber to be set Please note that the stages for PT must (!) match with the tendon assignments Balanced Cantilever Bridge 15 Bridge Design Tutorial 4.2 Groups: The group definition as done in SOFiPLUS is now important The activation of the individual groups has to be linked to the stage definitions Also define the age of the next segment when activated (emod, c+s) Balanced Cantilever Bridge 16 Bridge Design Tutorial 4.3 Loads: As in the coming menu “Control Parameters” all self weight is considered as per the group activations PT is clear, too and the traveler load has to be built in as external load the traveler load is activated and deactivated So it is loaded and unloaded 4.4 Control Parameters: This input here defines the automatic self weight activation as well as definitions for the precamber Also import it is to save the stress results of the stages Balanced Cantilever Bridge 17 Bridge Design Tutorial After calculation, please check animator, report with special regard to the Loading Case results 000+, 000+, 000+ 000+ In case of more than 999 construction stages the automatic generated LC numbers are 40 000+, 50 000+, 60 000+ 70 000 Balanced Cantilever Bridge 18 Bridge Design Tutorial Traffic loads: This task is based on the module ELLA and allows the analysis of traffic loads using influences lines/surfaces and the combination into envelopes As a first thing the deck is subdivide into lanes based on the selected design code For EC a centric, left-most and right-most arrangement is set up One can add as many load trains as wanted into the project In case a user defined train is required we refer to TEDDY input Balanced Cantilever Bridge 19 Bridge Design Tutorial As a next step we select the wanted degrees of freedom As results we get max/minN, max/min VY etc., each one with co-existing (associated) forces These envelope results are stored as “matrix” as in an XLS table (columns and lines): The column headers are called as the degree of freedom (N, Vy, ), the lines are following a numbering scheme that is based on a default set which can also be adjusted: Example: Line 101 Line 102 Line 103 Line 104 Line 105 Line 106 Line 107 Line 108 Line 109 Line 110 Line 111 Line 112 N maxN minN co-ex co-ex co-ex co-ex co-ex co-ex co-ex co-ex co-ex co-ex Vy Vz Mt My Mz co-existing (associated) forces co-existing (associated) forces maxVy co-existing (associated) forces minVy co-existing (associated) forces co-ex maxVz co-existing (associated) forces co-ex minVz co-existing (associated) forces co-ex co-ex maxMt co-ex co-ex co-ex co-ex minMt co-ex co-ex co-ex co-ex co-ex maxMy co-ex co-ex co-ex co-ex minMy co-ex co-ex co-ex co-ex co-ex maxMz co-ex co-ex co-ex co-ex minMz We now assign which load train is moving on which lane and set up so called “cases” each one representing a certain loading scenario Balanced Cantilever Bridge 20 Bridge Design Tutorial Also an “action” type has to be defined so that the program knows the category of the result envelopes Balanced Cantilever Bridge 21 Bridge Design Tutorial Balanced Cantilever Bridge 22 Bridge Design Tutorial The Max/min MY envelope is shown in the following graphics: Balanced Cantilever Bridge 23 Bridge Design Tutorial Combinations, design – CSM_DESI: For this part, there is not Graphic User Interface available The user has the possibility to set up individual combinations for the relevant ULS and SLS combinations (using module MAXIMA) and to the design manually (using modules AQB for beams and BEMESS for shell elements) Based on the result coming from CSM one can also extend the CSM to the design The CSM results are here combined with the final combinations of say temperature, traffic, settlement etc In addition to the actions to be combined with the stage results one can also shows elements for detailed stress checks on element level Similar to CSM a batch file consisting of input for MAXIMA, AQB and/or BEMESS is generated and executed This generated file called (project)_desi.dat can also be edited and modified Balanced Cantilever Bridge 24 Bridge Design Tutorial Decompression check (-): Balanced Cantilever Bridge 25 Bridge Design Tutorial Decompression check (-): Does not pass, varying of number of tendons as option to adjust design Balanced Cantilever Bridge 26 Bridge Design Tutorial Additional definitions: The example is extended by the following details: - The substructure is also linked to the girder, follows when changing the axis geometry Traffic is enhanced in such way that we now have two envelopes for UDL and truck loads: L_T and L_U This is part of the “Load groups” definition The combinations are not done using the automated CSM DESI wizard, but manually using MAXIMA Same for the ULS and SLS design: the necessary input is done manually in AQB instead of using the CSM DESI definitions In this part there is a warning message saying that no torsion reinforcement layer is found, this can be extended within the cross section if wanted Additional comments: The procedures shown here describe the general workflow for a simplified but real reinforced concrete bridge project Real projects will require a more detailed input for most of the parts specifically when doing combinations This example can be understood as getting started reference for a RC Bridge project using SOFiSTiK software Feedback will be much appreciated Please send us your comments via Email to support@sofistik.de with subject “Reinforced Concrete Bridge Tutorial” Balanced Cantilever Bridge 27