Geotechnical, Structural & Civil engineering — Brisbane & Queensland
Bridge Design Guide
Bridges combine structural, geotechnical and hydraulic engineering. This guide explains how we approach bridge design, foundations, abutments and assessment of existing bridges.
Start here
Many bridge problems start at the abutments and approach embankments, not the deck.
We design the superstructure, substructure and foundations together, including approach embankments, ground improvement and reinforced soil walls at the abutments.
Comparison
An overview only. Every entry below is described cautiously and is not an engineering limit; suitability is always confirmed against site-specific data.
| Bridge elements | Best suited to | Key consideration |
|---|---|---|
| Superstructure | Road, pedestrian and rural bridges. | Designed to AS 5100 traffic and environmental loads. |
| Piers & abutments | New bridges and abutment replacement. | Includes earth pressure, scour and seismic checks. |
| Foundations & approaches | Soft ground and high embankments. | Settlement and stability analysis with numerical modelling. |
| Existing bridge assessment | Ageing structures and increased traffic loads. | Assessment based on inspection and available drawings. |
Bridge elements
Each element is designed to AS 5100 and the client's requirements.
Bridge element 01
Concrete and steel decks, girders and bearings.
Road, pedestrian and rural bridges.
Designed to AS 5100 traffic and environmental loads.
Major bridges need a staged design and review process.
Bridge element 02
Piers, headstocks, abutments and wing walls.
New bridges and abutment replacement.
Includes earth pressure, scour and seismic checks.
Scour depth needs hydraulic input.
Bridge element 03
Piles, approach embankments, ground improvement and reinforced soil walls.
Soft ground and high embankments.
Settlement and stability analysis with numerical modelling.
A geotechnical investigation is required.
Bridge element 04
Condition inspection, load rating and rehabilitation of bridges and culverts.
Ageing structures and increased traffic loads.
Assessment based on inspection and available drawings.
Missing drawings may need testing.
Selection considerations
These factors tend to narrow the options faster than any single test result. Every recommendation remains site-specific and subject to the available data.
Method
Scope is adjusted to the project, the risk and the information already available.