THIẾT KẾ CẦU ĐÚC HẪNG CÂN BẰNG

Create a new project axis called “sys”, horizontal alignment as straight line New variable for section height: “H” units [mm]!:... 2.2 Cross Section New cross section called “box” used f

Bridge Design

Balanced Cantilever Bridge

FEA/SSD/SOFiPLUS Version 2014

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

Table of Contents

1  Project Description 4 

1.1  Geometry 4 

2  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 

1 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 ent chapters This enables you to start in the middle of the Tutorial if necessary

differ-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 model-ling, 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

Create a new project axis called “sys”, horizontal alignment as straight line

New variable for section height: “H” (units [mm]!):

Placements are so called “points of interest” along axis Here: we use “supports” and struction joints”

“con-Hint: use “station offset” for quicker definitions

Support axis @: 0, 10, 40, 100, 130, 140

Construction point/joints @: 10 - 40 incr 3.0m

40- 100 incr 3.0m 100- 140 incr 3.0m

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:

Close and calculate the section to also see CG and SC

Create new rectangular section for piers:

12.0m 0.25m 0.40m

6.40m

0.30m

2,80 / 0.15 m

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):

Note: group numbers for beam and spring elements must be defined correctly to match with construction sequence:

2.3 Load Case Manager

Go to LoadManager to define “Actions” and “ Loadcases”:

The define “Free loads“ for the actual loading and assign the loading the appropriate loading case

Example for “Pier settlement” (point load):

In addition to the shape the section also requires additional data such as reinf layers, stress points, geometry points, shear lag, shear cuts, etc Here only reinf layers for top/bottom, geometry points for PT and stress points top/bottom are defined Note that also the reinf lines require link to variable behavior

2.4 Cross Section - Reinforcement

Add reinf layers bottom/top to section:

Add a geometry point to section to which we refer to for the geometry of the continuity dons:

ten-Export structure to SSD, end of chapter 1, for modeling

3 Pre-stressing:

3.1 Tendon generation inside SOFiPLUS

Add new material: Y 1770 (EN 1992)

Add a pre-stressing system:

Create Tendons with PT-Editor (developed geometry) with SOFiPLUS:

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

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, tances etc These variables will make it easier to optimize the PT

dis-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)?

4 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 fined The TYPE has to be set as such that the program knows what it has to do All events have to be aligned along the time axis Only Creep + Shrinkage allow moving on the time axis

de-Also important is the link between tendon and stages

Schematic construction sequence:

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

Elements of stage 11 are 7+14=21days old

Creep+shrinkage 14 days

T14

2nd group activation (age 7), Self weight

to be applied

Stages for PT, traveler new and

to be applied

Stages for PT, traveler new and l

Creep+shrinkage 14 days Stage 31

Elements of stage 21 are 7+14=21days old

Elements of stage 11 are 7+14+14+14=49days old

T42

4th group activation (age 7), Self weight

to be applied

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)

pAfter calculation, please check animator, report with special regard to the Loading Case sults 4 000+, 5 000+, 6 000+ 7 000+

re-In case of more than 999 construction stages the automatic generated LC numbers are 40 000+, 50 000+, 60 000+ 70 000

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 maxN co-existing (associated) forces

Line 102 minN co-existing (associated) forces

Line 103 co-ex maxVy co-existing (associated) forces

Line 104 co-ex minVy co-existing (associated) forces

Line 105 co-ex co-ex maxVz co-existing (associated) forces

Line 106 co-ex co-ex minVz co-existing (associated) forces

We now assign which load train is moving on which lane and set up so called “cases” each

Also an “action” type has to be defined so that the program knows the category of the result envelopes

The Max/min MY envelope is shown in the following graphics:

6 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 IMA) and to do the design manually (using modules AQB for beams and BEMESS for shell elements)

MAX-Based on the result coming from CSM one can also extend the CSM to do the design The CSM results are here combined with the final combinations of say temperature, traffic, set-tlement 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

generat-ed and executgenerat-ed

This generated file called (project)_desi.dat can also be edited and modified

Decompression check (-):

Decompression check (-):

Does not pass, varying of number of tendons as option to adjust design

7 Additional definitions:

The example is extended by the following details:

- The substructure is also linked to the girder, follows when changing the axis try

geome 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 stead of using the CSM DESI definitions

in 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