The final product of a fully constructed bridge is often impressive. But what you often don’t see when you’re enjoying the view is all the tough, technical problems that went into its construction.
This guide breaks down some of the most common challenges engineers and contractors face during bridge construction. It’ll give you a better sense of what can go wrong – and how good bridge construction teams keep projects moving forward.
Thinking about a bridge project? Contact Struktis to find out how to avoid the most common pitfalls.
Problem ground – geotechnical constraints
Soft soils, reactive clays, shallow bedrock – all of these can throw serious curveballs at even the best-planned designs. If the ground can’t support the structure, you’re in for expensive redesigns, delays and even long-term settlement issues.
This is especially common in floodplains or former creek beds where soil conditions can shift dramatically across short distances.
How it’s managed:
Geotechnical investigations are critical early in the planning phase. Once soil profiles are known, engineers may opt for:
- Deep piles (long vertical elements driven deep into the ground) or screw piles (steel shafts with helix-shaped plates, like a corkscrew) to bypass poor upper layers
- Spread footings where soils are stable but shallow
- Preloading or soil stabilisation in high-risk zones
Miss the warning signs in the soil, and no amount of good design will save you from costly setbacks down the line.
Accounting for movement in bridge construction
Bridges don’t stay completely still. They can expand in the heat, contract in the cold, flex under load, and shift with time. If a design doesn’t allow for that movement, problems like cracking, fatigue, or bearing failure are almost guaranteed down the track.
Designers need to think ahead. That means accounting for:
- How the bridge will stretch and shrink with temperature changes
- The way people, bikes or vehicles will push weight across the structure
- Natural forces like wind, rain and vibration that stress the bridge over time
Material selection is part of this. Galvanised steel, weathering steel, concrete, timber – each one behaves differently under stress and changes in temperature.
How it’s managed:
Movement-friendly design features like expansion joints, elastomeric (flexible) bearings, and fatigue-resistant connections are built into the plans from day one. Modern engineers even run detailed simulations to test how the bridge will behave over time, not just on opening day.
Waterways and flood risks
Waterways can be unpredictable. They rise, fall, shift and drag trees and debris with them. Bridges constructed in flood zones have to handle high flow, scour at the footings, and potential impact from floating debris, all while keeping water levels stable for surrounding land.
Misplaced bridges can collect debris and worsen erosion. If the bridge span’s too short, it can choke the waterway and push floodwaters back upstream, raising flood levels. Even well-designed bridges can fail over time if hydrology isn’t properly considered from the start.
How it’s managed:
Hydraulic modelling is standard practice for bridges near water. Engineers use it to test how the structure performs under different flow scenarios. Solutions include:
- Elevating decks to avoid minor flood events
- Narrow piers and abutments to reduce flow disruption
- Rock armouring or other scour protection
Safety during and after construction
Safety isn’t just about the finished bridge – it starts from day one on-site. In public spaces, crews often work just metres from pedestrians, cyclists, or park users. Keeping the public away from machinery, debris and excavation zones is a full-time job, especially during high-traffic periods like weekends or holidays.
Plus, workers face their own set of hazards: operating in tight spaces, working at height, lifting heavy components, and coordinating around live services or weather conditions.
How it’s managed:
Contractors put detailed safety plans in place from the outset. That includes temporary fencing, clear signage, exclusion zones and safe access for workers. Once construction is complete, the bridge itself must comply with AS 5100 – with safe rail heights, anti-slip surfaces, and compliant barriers to reduce slips, trips and falls.
Managing traffic – including foot traffic
Parks and paths don’t close just because a bridge is being built. Whether constructing a pedestrian bridge or a vehicle bridge, contractors often work around pedestrians, cyclists, and even cars – all of whom still need safe passage.
That turns traffic management into a real design and logistics issue. Councils usually expect minimal disruption, and communities aren’t shy about voicing concerns when paths are blocked or detours aren’t clear.
How it’s managed:
- Staged construction keeps parts of the path open while the bridge goes in section by section
- Temporary detours or crossings are used to redirect users, but they need to be safe, well-marked and accessible
- Clear signage and communication helps avoid confusion and safety risks for locals and visitors
This is also where prefabrication plays a key role. Building components off-site cuts down on time, noise, and machinery on location. It’s faster, cleaner, and easier on the public.
Community and council approval
Council approvals can force changes to everything from alignment to material choice – especially in areas covered by environmental or heritage overlays.
Even small bridges might trigger requirements under flood, vegetation, or heritage planning schemes. Meanwhile, community consultation can influence design features, locations and delivery timelines.
How it’s managed:
Approvals are smoother when stakeholders are brought in early. That includes:
- Aligning with planning overlays from the start
- Working with Traditional Owners in areas of cultural sensitivity
- Preparing environmental and cultural impact documentation well in advance
Struktis case study: Managing community resistance at Lake Talbot
The Lake Talbot Skywalk in Narrandera faced more than just engineering challenges. Early on, community groups pushed back, worried the structure would disrupt the natural setting and spoil a popular recreation spot.
To manage the risk, Struktis and Narrandera Shire Council focused on early engagement. Community meetings, council backing, and regular progress updates helped shift public sentiment, especially once locals saw the project’s low-impact approach.
Key decisions helped ease concerns:
- Soil testing and careful foundation design to protect the site
- Prefabrication to limit on-site disruption, with photo updates for stakeholders to keep them involved
- A three-stage install to minimise impact on public access and the environment
By the time it opened, the resistance had faded. Locals saw that the structure didn’t take over the space. It enhanced it.
Read more about the Lake Talbot Case Study.
Struktis: experts at navigating bridge construction challenges
No two bridge projects are the same. But most run into similar kinds of challenges. The difference between delay and success often comes down to planning, collaboration, and knowing what you’re getting into before the first hole is dug.Have a project in mind? Get in touch with Struktis. We can tailor a solution for your site and make sure your project starts and finishes strong.