Every good bridge builder knows that no two bridge sites are the same.
From shifting floodplains and unstable soils to heavy vehicle access, every bridge project presents a unique combination of technical and environmental variables.
At Struktis, we handle every stage of the process, from initial site assessments to final installation and beyond, tailoring bridges to match the specific ground conditions, usage, and regulatory requirements of each project.
This is what a full-service bridge solution looks like in practice, from site assessment to certified handover.
Site assessment: terrain, flood levels, access, and existing infrastructure
Every bridge build begins with a detailed site review. This assesses:
- Topography and access — Is the site level or sloped? Can heavy equipment access it? Are there excavation limitations?
- Hydrology — Are flood immunity requirements in place (e.g. 1% AEP)? Are there scour risks? Is there tidal influence?
- Proximity to infrastructure — Are there underground services, pathways, or overhead clearances to factor in?
- Working envelope constraints — Especially relevant in parks, rail corridors, or roads with limited staging space.
The result is a clear technical framework for design decisions. For example, a shallow creek crossing with tight bank access may call for a prefabricated steel superstructure craned in with minimal disturbance. A flood-prone rural site may need a raised deck with high-clearance abutments and anti-scour protection.
Geotechnical testing and subsurface conditions
Geotechnical investigations are a standard requirement on every bridge site. These typically include:
- Borehole drilling
- Dynamic cone penetration testing (DCPT)
- Soil classification (plasticity, shear strength, bearing capacity)
- Groundwater table location
Typical findings inform foundation selection. For instance:
- Soft silty soils underlain by firm clay might require 4–6 m deep screw piles or driven steel tubes
- Sandy gravel at 1.2 m with high bearing capacity allows for spread footings
- Reactive clay with seasonal moisture variation needs deeper embedment or bored piers to avoid movement
We design foundations specifically for these results. This prevents future settlement, rotation, or overstress of superstructures.
Foundation design: spread footings, piles, screw piles, bored piers
Foundation systems are selected based on soil profile, structural load, and site constraints. Common solutions include:
- Spread footings: Cost-effective for shallow, competent soils (e.g. compacted gravel, weathered rock)
- Driven piles (steel or precast concrete): Used where soils lack shallow bearing or where construction speed is critical
- Screw piles: Ideal for low-vibration zones, soft ground, or environmentally sensitive areas (e.g. wetlands)
- Bored piers: Applied in rocky, irregular, or deep-bearing strata where driven piles are unfeasible
Design includes full detailing of depth, diameter, reinforcement, concrete strength, and exposure classification (to standards like AS 5100.4 and AS 3600).
Design for weight and load bearing
Use dictates design. Every bridge must be designed and engineered past the maximum load it will carry, not just for average traffic.
Vehicle bridges
- Designed to AS 5100 using SM1600, T44, or as required
- Load combinations include live load, dead load, wind, and flood forces
- Decking, girders, abutments, and bearings all sized for real-world service conditions
Pedestrian and shared use bridges
- Uniform distributed live load of 5 kPa minimum
- Additional wheel loads for occasional service vehicles or wheelchairs
- Dynamic effects and vibration limits considered (to ensure comfort, especially on long spans)
Environmental compliance: approvals, sensitive sites, and heritage constraints
Struktis manages environmental compliance from concept to delivery. This includes:
- Environment Protection and Biodiversity Conservation Act referrals for federally protected species or habitats
- State-level environmental approvals (e.g. Department of Transport and Planning in Victoria, Department of Planning and Environment in NSW)
- Flora and fauna assessments with construction mitigation plans
- Aboriginal Cultural Heritage checks and Cultural Heritage Management Plans where required
For example, boardwalks through vegetated wetlands are designed using narrow-diameter screw piles to minimise soil disturbance and maintain natural water flow. In urban heritage overlays, we coordinate bridge geometry and finishes with council heritage officers during planning.
Accessibility and safety compliance for shared and pedestrian bridges
All shared-path and pedestrian bridges are designed to comply with regulations like:
- AS 1428: For access and mobility, including ramp gradients, landings, handrail clearances
- AS 2156: Walking track infrastructure, applied in parks, trails, and reserves
- AS/NZS 1170: General structural actions — including wind, snow (where relevant), and maintenance loads
These standards ensure that every pedestrian or shared-use bridge provides safe, reliable access for all users, including those with disabilities, while maintaining structural integrity under a range of environmental and operational conditions. Compliance is engineered into the design from day one.
Fabrication and installation: modular construction, reduced downtime
Struktis bridge components are typically fabricated in-house. Off-site fabrication ensures greater quality control, faster assembly, and more consistent compliance with material standards.
During installation, the construction method is tailored to the site. In locations with restricted access or limited road closure allowances, installation may be staged using temporary bypass routes or carefully timed crane lifts to minimise disruption. Modular construction methods, including precast elements and pre-assembled spans, are often used to reduce time spent on-site and streamline the overall build (particularly valuable in high-traffic or environmentally sensitive areas).
Regulatory signoff and project handover
The final stage is about more than just handing over a finished structure — it’s about ensuring the bridge is compliant, documented, and ready to be accepted into service without delays. The post-installation stage includes:
- Detailed structural drawings
- Foundation and soil reports
- Welding and material certificates
- AS 5100 compliance signoff
- Certificates of practical completion and asset handover documentation
Struktis: Your bridge solution from start to finish
Struktis designs and engineers solutions that match the exact site, load, and compliance requirements of each project.
From soft ground and flood-prone creeks to shared-use footbridges in urban parks, we manage every stage of the process. Looking for a bridge that’s built to last, built to code, and built for your site? Get in touch with Struktis for bridge builders that tailor solutions for your site, or browse our past projects. Every site is different, and the right bridge is the one that’s built to match it.