ACES-PSC:  Design of pretensioned girders
ACES-PSC performs the design of pretensioned concrete Super-T beams to the Australian Standards bridge design code (AS5100.5). However, the module has been developed in a way that will allow you to easily change the design equations to suit other section types and codes (see later).  This (first) version of the module is based on a number of assumptions and restrictions that will be addressed in future releases viz:
 
  • Calculations are based on the general approach given in AS5100.5 - 2004.  However, two options are provided for performing the Ultimate Limit State (moment) check.  A method based on the Simplified Approach (a rectangular concrete stress block is assumed); and a Strain Compatibility Method (permitting partial prestressing to be used).
  • The concrete compressive block is entirely within the insitu concrete slab.
  • The compression block is above the void (if present).
  • The effects of torsion are not taken into consideration in the shear check.
  • The effects of section cracking are not taken into consideration.
  • A crack control check is not performed if the tensile stress exceeds the limit (refer to AS5100.5 Cl8.6.2).
  • A check for unbonded strand ratio is not performed.

The module can either be accessed directly from within the main ACES program or run in stand-alone mode. If run from within ACES all section properties and job attributes for a selected girder will be automatically transferred into the PSC module.  Note that member forces for relevant load cases are not imported from ACES - they must be entered manually.

Click here for a description of the design methodology adopted in ACES-PSC.

Click here to view an album of typical screen shots from the module.

Click here to view, print or download a flyer.
 

Features
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 Design Standards:  ACES-PSC performs the design of standard AS5100.5 open and closed trough pretensioned Super-T beams. However, section properties data for non-AS5100 Super-T sections can easily be saved to the Super-T database and accessed when needed. Alternatively, section properties for non-standard shapes can be calculated manually and entered directly into the system. Click here to view the section properties database file (Secprops.txt).
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 Design Equations:  While the design method incorporated into ACES-PSC is based on the AS5100 code, all equations and algorithms can be changed and customised to suit your own methodology. A separate and unique equations file sets out the design process.  This is a text file that can be edited using any convenient text editor (such as NOTEPAD or WORD). Equations can be modified, deleted or added to suit your own design requirements using a set of simple rules.  Logical functions such as IF..THEN, ITERATE, LOOP, MAX, MIN are available to handle complex algorithms involving some degree of logic. Click here to view the equations file incorporated into the current version of the ACES-PSC module.
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 Parameter Definitions:  Parameter definitions used in dialog boxes and equations can be changed to suit local conventions.  If you don't like the parameter names or descriptions used by ACES-PSC you can change them to suit your own tastes.  Parameter definitions are stored in a separate text file that can be edited using any convenient text editor (such as NOTEPAD or WORD).  Click here to view the parameter description file incorporated into the current version of the ACES-PSC module.
Analysis:  An EXCEL spreadsheet-style analysis process is used. Change a parameter, click the Recalculate button, and the entire design is redone.
Calculation Logs:  Calculation logs give detailed descriptions of every equation used in the analysis as well as the immediate value of every parameter and variable set during the calculation.  Calculation logs are available for different levels of design detail at the click of a View calcs button - either for the entire design; a specific part of the design (e.g., the section that only checks for shear); or for a sub-set of that one part (e.g., the check for flexural shear cracking).  Click here to view a typical calculation log.
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 Reports:  Output reports have been created in HTML (web browser) form. The full design logic and all equations and associated parameter values are shown in the report.  As a consequence reports can be customised to suit your needs using standard HTML editors. Click here to view a typical HTML report proforma.
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 Default Settings:  A large number of parameters can be preset and saved to a defaults file.  They will be auto-loaded into the module when a new design is initiated. Default parameters can be customised i.e., you determine which parameters are included in the default parameter set and what their initial values are. This is a text file that can be edited using any convenient text editor (such as NOTEPAD or WORD). Click here to view a typical default parameter definitions file.

Design Methodology
The full design logic and all equations and associated parameter values used by ACES-PSC are incorporated into the various output reports produced by the module.  To review the methodology used in the design process either click on one of the report proformas listed below or click here to view the full equations file.  In the report proformas you will see that the symbol, or name, associated with any particular parameter is enclosed in curly brackets.  When you click on any one of the Print ... buttons to produce a report the actual numeric values of all of these parameters will be substituted in place of the symbols (refer to the Examples section below to see what a completed report might look like).
  Estimating prestress forces
  Detailed calculation of prestress losses
Serviceability check
Ultimate moment check
Shear design
Deformations and hog
Although the design has been based on the AS5100 code, all equations and algorithms used in the design process can be changed and customised to suit your own design methodology. This can be done by editing the equations file using any convenient text editor (such as NOTEPAD or WORD).  Equations can be modified, deleted or added to suit your own design requirements using a set of simple rules that are described at the beginning of the file.  (Note that relevant report proformas may also have to be changed to reflect any modifications made to the equations file).
 

Example Reports
The reports below represent a typical design example.  Please note, however, that actual numeric values within any one report or between reports may not always be correct.  Values have only been included to indicate how a typical report might look when viewed through the "Print ..." button.
  
(NOTE! If data in the report looks "garbled" then try right-clicking the link and saving the target report as an '.mht' file to a suitable folder on your PC.  Do not save it as an 'htm' type file.  Once it has been saved double-click the file to open and view it).
  Job identification report
  Section properties
  Estimating prestress forces
  Detailed calculation of prestress losses
Serviceability check
Ultimate moment check
Shear design
Deformations and hog

Screen Shots

Section properties tab:

 

Prestress estimates tab:

 

Strand data form:

 

Prestress losses tab:

 

Serviceability check:

 

Ultimate moment check:

 

Shear check and reinforcement design:

 

Deformations and hog:



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