Engineering analysis + design software

Software Option for LUSAS Bridge versions

Steel and Composite Deck Designer (PontiEC4)

The Steel and Composite Deck Designer software option carries out comprehensive calculations for multiple sections on steel or steel/composite bridge decks to the Eurocodes, allowing otherwise time-consuming and error-prone manual design calculations to be carried out efficiently.

  • Perform rapid design calculations covering ULS bending, stress, shear and interaction; SLS stress, web breathing and fatigue checks for main members and connectors.
  • Consider multiple sections with different properties (haunches, stiffeners, etc), and also bolted connections. 
  • Output results in tabbed dialogs that visually show values that pass or fail. 
  • Easily create graphs and a report containing all input data and output with references to the Eurocode clauses.

Force and moment results for selected bridge deck elements are provided by LUSAS and loadcase combinations defined within LUSAS are associated with design limit states and phases defined in the Steel and Composite Deck Designer.

For steel and composite deck design to AASHTO 8th Edition see Software Option - Composite Bridge Deck Design.

Design members

Use the Steel Composite Bridge Wizard to automatically create the required Composite Bridge Deck Design members when bridge design materials are additionally specified for all I-girders. Add details for transverse stiffener design also.

Define additional design details for each design member using a tabbed dialog. Span lengths, segments (a portion of a span defined by a constant or tapered section), bracing locations, web stiffeners, shear connectors and locations at which design checks will be made, can all be specified.

Composite Bridge Deck Design member dialog

Design checks supported

Carry out design checks for any number of construction phases:

  • Phase 1 Self weight
  • Phase 2a Permanent loads
  • Phase 2b Concrete Shrinkage
  • Phase 2c Imposed deformations/prestressing
  • Phase 3a Thermal actions
  • Phase 3 b Traffic loads

For each construction phase, design checks are made for each of the following combinations:

  • ULS Fundamental EN 1990 (3)
  • SLS Characteristic EN 1990 6.5.3 (2a)
  • SLS Frequent EN 1990 6.5.3 (2b)
  • Fatigue EN 1992-1-1 6.8.3

Typical application

LUSAS model

Section definition

Deck section information is defined in the Geometry dialog of the Deck Designer and is organized in a tree structure. 

Advanced options

Advanced options allow the specification of web and flange stiffeners and permit the buckling of longitudinally stiffened flanges to be considered.

Bolted connections

Bolted connection details are supported

Material definition

Input of material properties is straightforward and can be adjusted to suit project requirements.

Assistance with setting codified parameters

Dialogs assist with the calculation of effective widths and shear lag, and the setting codified parameters such as fatigue damage equivalent factors for shear studs, structural steel and reinforcing bars 

Forces and Moments

Construction stages and in-service conditions are assimilated and design combinations organised in groups. 
Load effects for the various sections to be checked are displayed in a spreadsheet style. 

Design calculations and results output

Automated ULS, SLS, fatigue and other calculations


  • Section properties
  • Primary (isostatic) effects of shrinkage and temperature change
  • Creep and shrinkage coefficients (EN 1992-1-1, App B)
  • Classification of sections (EN 1993-1-1, Table 5.2)
  • Ultimate bending check for Class 1 & 2 sections (EN 1993-1-1, 6.2.5)
  • Stress checks for Class 3 and Class 4 sections (EN 1993-1-5, Section 4)
  • Ultimate shear and web buckling (EN 1993-1-5, Section 5)
  • Bending-shear interaction (EN 1993-1-5, Section 7)
  • SLS stress checks (EN 1994-2, 7.2.2 (5) and EN1993-2, 7.3)
  • SLS web breathing check (EN1993-2, 7.4)
  • Reinforced concrete crack checks (EN 1994-2, 7.4(3))
  • ULS, SLS and fatigue checks for connectors (EN 1994-2, 6.6 and 6.8)
  • ULS, SLS bolted connections (EN 1993-1-8)
  • Fatigue checks for both structural steel and reinforcement components (EN 1993-1-9, EN 1994-2, EN 1993-2)
  • Transverse and longitudinal stiffener checks (EN 1993-1-5, 9.2.1 and 9.3.3)

A multi-tabbed results dialog gives access to the results for each of the design checks made for each deck section.

Results pages

Emphasis on descriptive graphics e.g. bending-shear interaction diagram with the web contribution included or excluded

Results Summary

A Results summary dialog shows (as on all dialogs) at-a-glance viewing of pass / fail values for sections. 
Values passing a design check are shown in green, those failing are shown in red)

Crack checking

Where required, reinforced concrete crack width limitation can be carried out 
using the indirect method according to EN 1994-2 7.4 (3).


Pre-defined graphs of utilisation factors, stresses, longitudinal shear per unit length, force and moments, etc. are easily plotted. 
User-defined graphs can also be created.


Reports, containing all or selected input and results data, are created with references to Eurocode clauses.

Section Optimisation

Section optimisation can be carried out by editing the geometry/material data in the Deck Designer and then viewing (also in the Designer) how the changes have affected the results. If required, the revised properties can be re-exported to LUSAS to carry out a final iteration and check, but this will not always be necessary.

Bridge types supported

Composite I-girder

Composite I-girder

Composite I-girder

Composite ladder deck

Composite box girder

Composite box girders

Steel box girder with orthotropic plate

Steel girder with orthotropic plate

Half-through bridge 

Half-through bridge 

Some projects undertaken using the Steel and Composite Deck Designer

Bridge over the Serchio river, near Castelnuovo di Garfagnana, Tuscany, Italy



For Composite Deck Design to AASHTO 8th Edition (2017) use the Composite Bridge Deck Design option.

Software Information

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Any modelling, design and analysis capabilities described are dependent upon the LUSAS software product, version and option in use.