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Software Licensing Terms

Data Security

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Data Security Notice Updated 27th February 2020

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Website Terms and Conditions

The contents of this web site are protected by copyright and other intellectual property rights under international conventions. No copying of any words, images, graphic representations or other information contained in this web site is permitted without the prior written permission of the webmaster for this site.

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Software Licensing Terms

Terms and Conditions of Purchase

The full conditions of purchase and maintenance for all Oasys desktop software are set out in the Oasys Software Licence and Support Agreement.

The full conditions of purchase and maintenance for Oasys Gofer are set out in the Gofer SaaS Agreement.

All prices are subject to TAX at the current rate.

Prices and specifications are subject to change without notice – please ask for a written quotation.

Although every care has been taken to ensure the accuracy of all information contained herein, the contents do not form or constitute a representation, warranty, or part of any contract.

Superseded Versions of Terms and Conditions

Oasys keeps copies of all superseded versions of its terms and conditions.

Maintenance & Support Services

Support and maintenance is included with all subscription licences for their full duration.

Annual maintenance contracts are available for software under a perpetual licence, prices are based on a percentage of the most recent list price.

This service includes:

  • telephone/email/web based support
  • free software updates available via internet download
  • personalised output header for many products

GSA Bridge

The perfect tool for busy bridge designers, GSA Bridge automates the optimisation of bridge loads (such as vehicle and lane loading) to a variety of international codes and checks for pedestrian footfall vibration. With a wide range of structural analysis types and 3D and 2D graphics for post-processing, bridge design analysis has never been easier.
GSA Analysis GSA Building GSA Bridge GSA Suite
Modelling Tools

Text, graphical and automatic creation of geometry and loads

2D and 3D Elements

Covers all element types in GSA such as 1D, 2D, 3D, and spring elements.

Linear and Nonlinear Static Analysis

Compression-only struts, tension-only ties, non-linear springs, and cable

Linear and Nonlinear Dynamic Analysis

Analyse for geometric and material non-linearity over large deflections

Non-linear Materials

Elastic-Orthotropic and Elastic-Plastic Isotropic materials

Linear Analysis

1st order static analysis

Staged Analysis

Add, remove, and change elements and constraints within analyses

P-Delta Analysis

Analyse for the changes in stiffness caused by load

Dynamic Analysis & Response

Modal and Ritz analysis, including P-Delta effects with Seismic, Harmonic, Linear Timer History, and Periodic analyses

Buckling Analysis

Modal buckling of 1D & 2D elements, Non-linear buckling of 1D elements

Wave Loading

Generate wave and current loads on submerged structures

Raft Analysis

Combine structural models with non-linear soil for foundation design

Bridge Loading

Lane and vehicle load optimisation for highway and railway bridges

Footfall Analysis

Calculate accelerations, velocities and response factors from pedestrian loading

RC Design

Design of reinforced concrete slabs and walls to international standard

Steel Design

Design of steel beams, columns, and braces to international design codes


Geometry generation for tension and compression only structures

Fabric Analysis

Analysis of fabric non-linear materials

Simulate advanced bridge design engineering problems with accurate tools

GSA Bridge has proved its worth as a key piece of bridge engineering software on award-winning projects such as the Infinity Footbridge, the Falkirk Wheel, and the Gatwick Air Bridge.

Part of the GSA suite of programs, GSA Bridge is the perfect bridge design software for busy bridge designers. This easy-to-use bridge analysis software automatically sifts through the multiplicity of possible moving loads to find the crucial loads for your structure.

GSA Bridge will also design the steel beams and slab rebar for you to a variety of national and international codes, determining what is needed to carry the load.

As designs become more efficient, the resulting structures get lighter and more responsive to human induced vibrations. GSA Bridge thus includes the advanced footfall module and is the leading program available for vertical footfall analysis on any structure.

How GSA Bridge Works

Input: Create structural finite element analysis models using CAD and BIM links, directly in the table or graphical views, or using your own scripts via the Application Programming Interface. Assign linear and nonlinear materials to a variety of element types, whether beams from catalogues, standard shapes, profiled slabs, or your own special requirements. Add static, dynamic, prestress, or thermal loads and analyse the effect.

Analysis and Design: GSA includes several solvers, including:

  • bridge load optimisation
  • steel member and concrete slab design
  • footfall analysis for human induced vibration
  • matrix-based stiffness method for static and p-delta analyses
  • dynamic relaxation and explicit solvers for nonlinear static and dynamic problems
  • eigenvector solvers for modal vibration and buckling analyses
  • dynamic response analyses for seismic response spectrum or time history, harmonic and periodic vibrations
  • soil structure interaction for rafts and piled structures
  • diagnostic analyses for resolving modelling problems

GSA will find the lightest, shallowest, cheapest, or most environmentally friendly steel beam section to carry the load, and work out the ideal quantity of reinforcement in your concrete slabs and walls.

Output: Output forces, moments, deformed geometry, and other results in graphical views, tables, and graphs. Export analysis models to LS DYNA, model changes to Revit, or text and numbers to Office documents.

Key Features & Benefits

  1. Find the footfall response over the whole structure, with full contour plots and detailed graphs showing exactly where the satisfactory and problem areas are
  2. Optimised vehicle and lane loading is produced automatically offering a real time saving
  3. Perform day to day analysis and solve complex engineering problems within the same environment

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Capabilities of GSA Bridge

Visit the full change log for all improvements

Redesigned and streamlined user interface – Quick access to popular tasks with customisable panes and toolbars.

New beam section – Improve interoperability by allowing you to define any section once and then being able to reuse it within any Oasys software program.

New Beam Section

Materials – Define design grade materials at the analysis and model building stage. Build user-defined materials.

Grid loading – Work with 1D or 2D elements, allowing patch, line, and bridge loads on meshes.

IFC import & export with GsRevit – Interchange data between a variety of BIM friendly platforms with GSA 9.0’s new IFC import and export. As well as new Revit integrations allowing you to map entities with ease.

IFC model imported into GSA

Explicit solver – A new analysis solver for dealing with short time-span, high frequency dynamic non-linear situations has been implemented along with improved load curves functionality.

Seismic analysis – New advanced seismic analysis features include response spectrum analysis with improved display, tools and combinations.

3D solid elements & soil structure interaction – Now includes 3D solid (brick) elements allowing a wide range of structural properties to be simulated. New Contact and Damper element types have been introduced to model dynamic problems such as modelling contact between different elements.

Brick Element: Diagram – Surface Contour – Filled Contour

Raft Analysis – The Raft Analysis feature is now available in all GSA variations. This analysis type is perfect for busy foundation designers. This easy-to-use feature combines non-linear structural and geotechnical models to calculate accurate settlements, soil pressures, bending moments and other structural stresses in a fraction of the time.

Design improvements – Design materials have improved functionality and create more consistent models.

Steel member design – Improved member design that provides analysis releases along with in-depth functionality options with instant results in report view.

Steel Design

Member libraries


New chart views, reporting and graphics – In addition to the instant report view results, chart view functionality is improved with easy updating and exporting of curves. Graphics have been improved making your 3D model and 2d graphic look even better.

New Chart Views

Improved Graphics

API improvements – New features include direct objects for Members that lead to faster access and productive code development, expansion of existing objects, and the ability to run automated design from the API using the new Design Task functionality.

Automated bridge loading to:

  • Australia: AS 5100 2, M1600, S1600, M1600-Triaxle, SM1600
  • Eurocode: EC1 UK, generic, user defined
  • Hong Kong: SDM
  • UK: – CS 454, BD37, BD21 HB, BD86 SV TT / Train / 150 / 100 / 80, UIC71, RU, RL, SW/0, SW/2, HA, HB, SV
  • US: AASHTO 17, LRFD 3, H20-44, HS20-44. HL-93

Path and vehicle loading to

  • Australian Highway Loading: M1600, S1600, M1600-Triaxial, SM1600
  • Eurocode Loading: Generic, UK, user defined
  • UIC and UK Railway Loading: UIC71, RU, RL, SW/0, SW/2
  • UK and HK Highway Design Loading: HA, HB, CS 454(ALL 2)
  • US Assessment Loading: SV
  • US Highway Loading: H20-44, HS-20-44, HL-93

As designs become more efficient, the resulting structures get lighter and more responsive to human induced vibrations. This means that footfall induced vibration is becoming an important serviceability design requirement for office and residential buildings, foot bridges and staircases: it is an essential requirement for demanding situations such as hospitals, footbridges and laboratories.

GSA enables you to find the footfall response over the whole structure, with full contour plots and detailed graphs showing exactly where the satisfactory and problem areas are. You can thus explore cost-effective design solutions and advise you client on how their structure will respond to human induced vibration.

Product benefits

  • GSA is the only program available that allows you to analyse any structure for footfall analysis, whether an irregular floor, a bridge or a staircase, whether concrete, steel, or composite.
  • Quick and accurate predictions of resonant and transient response to footfall vibrations, including response factors, peak accelerations, and peak, RMS and RMQ velocities.
  • Define areas of interest on a floor; e.g. the effect of running down a corridor next to an operating theatre

Footfall analysis 

Sensitivity to vibration is becoming increasingly significant as advances in structural design result in lighter structures; the lighter the structure the more sensitive it is to induced vibration.

Footfall analysis methods

  • Arup / Concrete centre method – Concrete Centre CCIP-016
  • Steel Construction Institute – P354
  • American Institute of Steel Construction – Steel Design Guide 11
  • Staircase method – CCIP-016 & SCI P354


GSA combines GSA structural model with a 3D brick or Pdisp soil model to calculate the soil structure interaction.

  • Direct finite element analysis using brick elements and friction spring interaction elements
  • Iterative analysis using the GSA and Pdisp solvers (does not need the installation of Pdisp)
  • Specify soil properties and locations
  • Specify soil-structure geometry
  • Raft & Pile soil structure interaction

Find how your structure interacts with the ground for the optimum foundation design

Raft is perfect for busy foundation designers. This easy-to-use software combines non-linear structural and geotechnical models to calculate accurate settlements, soil pressures, bending moments and other structural stresses in a fraction of the time.


  • Multiple soil profiles
  • Multiple soil zones
  • Linear or nonlinear soils
  • Pile soil interaction coefficients (p-y, t-z, q-z)
  • Additional soil loads
  • Pdisp import/export

Design of reinforced concrete slabs and walls to:

  • Australian: AS 3600-2001, 2009
  • Eurocode: EN 1992-1-1:2004 Eurocode 2 – General, Denmark, Germany, France, Italy, Netherlands, & United Kingdom
  • Hong Kong: Hong Kong Code of Practice 1987, 2004, & 2004(AMD1), HK Structures Design Manual-2002
  • India: IS456:2000
  • UK: BS 8110-1:1985, 1997, & 1997 (Revised 2005); BS 5400
  • US: ACI 318 & 318M – 02, 05, & 08

Output options

  • Output of areas of steel on easy to rationalise contour plots
  • Output of moment: ultimate moment ratios

Design of steel members to:

  • Australia: AS 4100:1998
  • Canadian: CSA S16-09
  • Eurocode: EN 1993-1-1:2005 Eurocode 3 (including French, Dutch,  UK, Singapore, and UK fire annexes)
  • Hong Kong: HKSUOS:05 & 11
  • India: ISS 800:1984 & 2007
  • UK: BS 5950-1:2000
  • South African: SANS 10162-1:2011
  • Generic: Stress check

Output options

  • Contouring of utilization ratios
  • Tabular output of utilization ratios and verbose and brief calculations
  • Colour highlighting of errors and warnings in calculations
  • Automatic calculation of effective buckling lengths based on specified member restraints

Steel member design features include:

  • Support for curved and explicit members
  • Results are available in various forms, including numeric utilization ratios and calculations as rich text.
  • The different forms of result available mean that the user can avoid information overload, but can still audit the calculations at a very basic level when appropriate.
  • Utilization ratios can be plotted (contoured) on the model just like any other numeric result, so enabling rapid understanding of which parts of a structure are overstressed or are over designed.
  • Calculation results are marked up in colour to draw attention to problems and important results within the calculations. They are available in both brief and verbose formats.
  • Restraints can be specified in detail so that the program can evaluate the effective buckling lengths of complex multi-span beams. Alternatively, the user can specify the effective lengths (as is common in other steelwork design packages). Assistance is available to set up restraints, which are necessarily more complex than restraints used in analysis models.

Nonlinear analysis

Analyse structures with large and very large deflections, plastic yielding of materials, snap-through, sway effects, and more. GSA Analysis uses the dynamic relaxation method to analyse structures that are too large and complex for other programmes.


Buckling analysis

GSA Analysis enables you to calculate the buckling load factors on a range of structures, from complex frames to shell structures and lateral torsional buckling of plate girders. It also includes non-linear buckling effects so you can plot the deflections of columns and struts against load to accurately assess safety factors.


Dynamic analysis and response

GSA Analysis includes both modal analysis for calculation of the natural dynamic frequencies of your structure and Ritz analysis specially designed for seismic response calculations. You can choose to include axial load effects to change stiffnesses in both these methods.

Following on from the modal or Ritz analysis, GSA Analysis enables you to calculate the structural response using a number of dynamic post processors, including seismic response to multiple international codes, linear time history, harmonic loads for vibrating machinery, and more.



With staged analysis you can assess the model at any stage in construction, remove elements, and change sections and restraints, coordinated in a single model.

GSA offers a wide range of structural analysis types

  • Static analysis
    • Linear Static
    • Static P-delta (p-delta by own load case, different load case, or previous analysis case)
    • Non-linear static
  • Dynamic analysis
    • Modal
    • Modal P-delta
    • Ritz
    • Ritz P-delta
  • Dynamic Response
    • Response spectrum
    • Harmonic
    • Linear Time History
    • Footfall
  • Buckling
    • Modal / eigenvalue
    • Non-linear member buckling
  • Mass analysis
  • Form Finding
  • Analysis envelope
  • Model stability diagnostic analysis

Analysis features:

  • Wizards to guide users in setting up data and analyses
  • Solution methods
    • Sparse Direct & Sparse Parallel Direct
    • Conjugate Gradient
    • Active column
    • Dynamic relaxation
  • 2D skeletal frame and grid analysis
  • 3D skeletal frame and shell structural analysis
  • Non-linear
    • Strut and tie elements, fabric elements
    • Materials
    • Load increments
  • Analysis in construction stages
  • Two dimensional and axisymmetric analysis
  • Large capacity
  • Efficient and stable solution algorithms
  • Analysis of applied load, applied displacements and settlements
  • Export of data to other analysis programs
  • Selective storage of results
  • Element pre-load by prestress for initial p-delta effects

Analysis stage specification:

  • included elements per stage
  • element properties per stage
  • constraints per stage

When an analysis is requested the data are checked for inter-module consistency. If errors are detected, a report is prepared and the program returns to the data editing options; if not, the program proceeds with the analysis with progress being reported to the screen throughout

Analysis control

  • analysis is specified and controlled by analysis tasks
  • default analysis task is set up automatically for typical analysis: linear static analysis of all load cases
  • explicitly defined analysis tasks are defined via the analysis wizard
  • pre-analysis data checks check for inter-module consistency, reporting to the report view
  • report view messages link to related data
  • pre-analysis checks can be invoked explicitly
  • several analysis tasks can be queued for batch analysis

Case control

  • Load cases
    • load container
  • Analysis cases
    • result container
    • may be described in terms of compound load cases
  • Combination cases
    • described in terms of compound analysis cases
    • descriptions may reference other combinations
    • results calculated for combination cases on-the-fly
  • Enveloping
    • described as a special combination case
    • analysis envelopes enable enveloped results to be stored


For regular structures, a Data Generation wizard will allow the user to specify the structure in terms of few key parameters and automatically generate the model data. For more complex structures structural geometry and loading data may be input through either the graphical data generator (“Sculpt”) or a more traditional spreadsheet format

Sculpt enables all structural geometry to be rapidly generated and edited on the screen using a cursor controlled by a mouse. Dynamic viewing makes it possible to adjust the model as required

When the structure is complete, all loading may be similarly generated and displayed diagrammatically. Structures of complexity varying from simple to large skeletal frame models can be generated and complex 2D element meshes can be generated using the automatic mesh generation facilities

The alternative spreadsheet method incorporates many useful features for the generation and copying of numerical data. Text input is normally specified by selection from a list of available items rather than by entering numeric codes.

The API enables GSA to be driven from a spreadsheet macro or other external program. In addition, the command line interface enables GSA to be driven from batch files.

GSA includes a bi-directional link between GSA & Revit 2014, 2015, 2018 and 2019, Revit Structure 2013 & Revit Structure 2012. With this Revit users can transfer model information between Revit and GSA with minimal loss of data.

Data from tables can be transferred to and from spreadsheets using the standard cut and paste facilities. The GWA file (ASCII data file) is written as a tab-separated file to facilitate input into spreadsheet programs


Import options

  • AutoCAD DWG / DXF
  • CIMsteel CIS/1
  • Revit Structure (see below)
  • Pdisp

Export options

  • ADC
  • ASAS
  • AutoCAD DWG / DXF
  • CIMsteel CIS/1
  • OpenSees
  • Revit Structure (see below)
  • SAP2000
  • Steel Member CSV
  • Pdisp

Hong Kong engineers get go ahead to use GSA 10

Oasys GSA 10 has been pre-approved for use in calculations for steel member design used to support applications for submissions to the Hong Kong government authorities.

As with all such pre-approvals, it still leaves the onus on engineers to check that the program is applicable, that its assumptions are valid for each project and that it is correctly configured. So the pre-approval of software developed by the trusted Oasys team will be welcome to engineers working throughout the Territory.

See the list of pre-accepted computer programs for full details.

Following several requests from customers we have developed a small utility to allow those customers who have multiple variants of GSA shared licences to easily swap between them.

  1. This document refers to the utility installed with GSA version 9.0. For any earlier version, please contact us for details.
  2. Activate one of your GSA keys as follows
  • Open GSA
  • From the ‘Help’ menu choose ‘About GSA’
  • Click on ‘Manage License’
  • Click ‘Activate’
  • Enter the License Key & Password for the first variant of GSA that you have
  • You do not need to repeat these steps for the other variants of GSA that you have as GSA will find these in the License Database
  • Close the program
  1. When you next open the program, the variant that opens will be the one that you activated the key for last.
  2. To change the variant you wish to open, close GSA and run Oasys Key Switcher
    (Closing GSA is important to stop activations becoming locked on your machine). The Switch Keys utility won’t open if you are already running GSA 9.0.
  • For Windows 7 you can run Oasys Key Switcher from ‘Start > All Programs > Oasys GSA > Oasys Key Switcher
  • For Windows 8 and 10 you can find Oasys Key Switcher on your ‘Apps’ screen

5. Select the variant you wish to run and then open GSA. Each time you open GSA after this, it will run the last activated variant until you run Oasys Key Switcher again and select another variant.

Explore GSA Bridge Solutions

Other GSA Applications

GSA Suite

Structural engineers designing buildings, bridges and tensile structures need comprehensive software to get robust results. Tackle any structural engineering challenge with this complete structure design and analysis software package. GSA Suite gathers the benefits of all the GSA variants into one single offering.

Find out more »

GSA Analysis

GSA Analysis is used around the globe on all manner of projects. It provides engineers with a highly intuitive nonlinear analysis software tool to help realise the potential of design, no matter the challenges.

Find out more »

GSA Building

GSA Building is part of the Oasys General Structural Engineering suite and combines steel and concrete design, footfall, and soil-structure interaction analysis in the same building design software package. With this intuitive software, you can design structural models with skeletal frames and two-dimensional finite elements, enabling you to design and analyse even the most complex buildings.

Find out more »

Infinity Bridge

With a main span of 120m, secondary span of 60m, and arch height of 40m, the award winning Infinity Bridge is one of the largest footbridges in the UK.

View Case Study »

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Please select what type of licence you would like to purchase

GSA – Bridge

USD $3,611.79USD $8,871.46

The perfect tool for busy bridge designers, GSA Bridge automates the optimisation of bridge loads (such as vehicle and lane loading) to a variety of international codes and checks for pedestrian footfall vibration. With a wide range of structural analysis types and 3D and 2D graphics for post-processing, bridge design analysis has never been easier.

Total: USD $0.00
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Structural design and analysis software

Additional information

Select your licence

Standalone, Network Floating, Network Floating International

I would like to

12 months Subscription (Pay annually), 36 months Subscription (Pay annually)

What should I choose?

Standalone licenses are locked to an individual machine, but transferable by the user to another machine manually. Ideal for single users. Restricted to use within the country stated in the End User address submitted by Licensee to Oasys at the time of purchase.

Network Floating licenses can be activated on any number of machines, however you can only concurrently use the number of licences that you have purchased. Ideal for users requiring more flexibility or when working as part of a team. Restricted to use within the country stated in the End User address submitted by Licensee to Oasys at the time of purchase.

Network Floating International licenses can be activated on any number of machines, however you can only concurrently use the number of licences that you have purchased. Ideal for users requiring more flexibility or when working as part of a global team. Eligible for deployment world-wide at the Licensees leisure.

*Prices shown are per year cost

Both Subscription options will allow you the right to use the software for the defined term, with the full maintenance and support service included for the duration. The price will be fixed for the duration of the agreed term after which it will automatically renew for the same duration at the then current price.

12 month pay annually – Single payment for the full term at the commencement of the Subscription period

36 month pay annually – Three annual payments split the cost over the Subscription period. All payments are fixed at the time of purchase and are not subject to variance over time. Lower annual cost in comparison to 12 month option.

Keeping your software licences maintained gives you full access to technical support (telephone, email and web based) and ensures that your software is kept up-to-date with free downloadable updates. Maintenance is only available to existing licences and lasts 12 months. It is highly recommended that you keep your software licences maintained. Maintenance duration will be calculated from the date of expiry of the previous maintenance/initial warranty. If you are purchasing maintenance for licences that have been unmaintained for longer than 12 months please contact us in order to renew.

"GSA has a highly responsive interface which facilitates an intuitive understanding of model behavior. For example, it allows for smooth rotation and magnification of the model while viewing enveloped results, allowing for effective post processing within the program itself. Many other structural analysis programs move sluggishly or not at all when results are displayed, and full post-processing of results must be done in other programs to be effective"
Allan Olson, - Arup

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