Steel Structure River-Crossing Bridge -Connecting Shores Defying Limits

Why Engineers Choose Our Steel River Bridges

1. Uninterrupted Navigation Below
No piers in the fairway. Our arch, truss, and cable-stayed configurations achieve clear spans of up to 500 meters, allowing barges, cargo ships, and recreational vessels to pass without constraints or collision risks.

2. 50–70% Faster Erection than Concrete
Prefabricated steel segments are delivered to site via barge or truck, then assembled with high-strength bolted splices. No falsework, no propping, no prolonged river closure. Your timeline shrinks by months.

3. Naturally Adaptive to Complex Geotechnics
Soft alluvial soil? Deep bedrock? High seismic zone? Steel's light self-weight (typically 30–50% of a concrete equivalent) dramatically reduces foundation loads and piling requirements — often saving millions in substructure costs.

4. Live Loads from Pedestrians to Heavy Trucks
Engineered for mixed traffic: dual 3.5 m lanes for vehicles (HL-93 or AASHTO loading) plus 2.0 m sidewalks with 5 kN/m² pedestrian live load. Optional rail line integration (UIC 71 loading) for light or heavy rail.

5. Lifecycle Durability in Wet Environments
Water + steel = risk. We eliminate it with shop-applied 3-layer paint systems (epoxy zinc-rich primer + micaceous iron oxide intermediate + polyurethane topcoat) or hot-dip galvanizing (≥100 μm). Design life: 100 years with routine maintenance.

6. Architecturally Distinctive
A bridge is a landmark. Choose from deck arch, through truss, tied arch, cable-stayed, or steel box girder profiles. Custom paint colors, decorative lighting integration, and railing patterns turn infrastructure into icon.

Wasiliana Sasa

Mafafanuzi ya Bidhaa

Product Details — Where Engineering Meets the River

Structural Configurations (Span-Dependent)

Bridge Type	Typical Span (m)	Best For	Key Visual Feature
Rolled/Plate Girder	20–60	Short spans, low clearance	Clean horizontal lines, shallow structural depth
Through Truss	50–150	Medium spans, heavy rail or truck loads	Triangular web pattern, open views
Deck Arch	80–250	Deep valleys, solid rock abutments	Rib arches rising above deck level
Tied Arch (Bowstring)	100–300	Flat terrain, navigable rivers	Arch above deck, tension tie at deck level
Cable-Stayed	200–500	Long spans, signature projects	Fan or harp cable patterns, single or double pylons
Suspension	300–1000+	Extreme spans, major river crossings	Sweeping main cables, stiffening truss

Steel Material Specifications

Main girders / trusses: Q370qD / Q420qD (weathering bridge steel) or S355N / S460N per EN 10025-3
Orthotropic deck: 14–20 mm thick steel plate with 8–12 mm U-rib stiffeners (hot-formed)
Bolting: High-strength friction-grip bolts (Grade 10.9S), pre-tensioned to 0.7× ultimate tensile strength
Welding: Full penetration butt welds; 100% UT (ultrasonic) testing on all tension members

Deck Systems & Wearing Surface

Steel Orthotropic Deck (Standard for spans >80 m)

14–20 mm deck plate + 8 mm closed trapezoidal ribs spaced 300–600 mm c/c
Wearing surface: 50–75 mm gussasphalt (mastic asphalt + stone chips) or 40 mm thin-layer epoxy asphalt
Fatigue design: Detail categories per Eurocode 3 (EN 1993-2) to 100 million cycles

Concrete-Steel Composite Deck (Economical for 40–120 m spans)

Steel girders with headed shear studs (19–22 mm diameter, 150 mm height)
Cast-in-place reinforced concrete slab (200–300 mm thick, C30/37 to C50/60 grade)
Shrinkage-compensated concrete with corrosion-inhibiting admixtures

Hydraulic & Navigation Integration

Waterway clearance (vertical): 8–45 meters depending on vessel class (minimum 4.5 m for recreational, 22 m for seagoing)
Horizontal clearance (between piers/arches): Unobstructed width = 90% of main span (no piers in water)
Scour protection: Riprap stone aprons or articulated concrete blocks around any in-water foundations
Flood resilience: Deck elevation set 1.0–1.5 m above 100-year flood level + freeboard

Foundation Options (Steel-Compatible)

Foundation Type	Suitable Geotechnics	Cost Impact	Installation Time
Driven steel pipe piles	Soft to medium alluvium	Low-medium	Fast (1–2 weeks per pier)
Screw piles	Clay, silt	Low	Very fast (no hammer noise)
Micro-piles	Limited access, rock near surface	Medium	Moderate
Spread footing on rock	Competent bedrock	Medium-high	Slow (excavation + formwork)

Seismic & Dynamic Performance

Seismic design: Capacity-protection principles per AASHTO LRFD or Eurocode 8; isolation bearings (lead rubber or friction pendulum) for high seismic zones
Wind stability: Cross-section verified for vortex shedding and flutter (wind tunnel test recommended for spans >200 m)
Fracture control: Charpy V-Notch testing at -20°C to -40°C; fatigue detail categories B or C for primary members

Safety & Operational Features

Vehicle barriers: Concrete or steel guardrails (Test Level 4–6 per EN 1317 / MASH), height 0.8–1.1 m
Pedestrian railing: 1.2–1.4 m height with 100 mm max opening (child-safe)
Drainage: Stainless steel scuppers at 10–15 m intervals discharging to end-of-bridge treatment
Lighting: Integral parapet lighting (LED strips) or decorative pole-mounted luminaires
Maintenance access: Internal walkway inside box girders (height ≥1.8 m) plus external catwalks under arches

Corrosion Protection System (Immersion Zone + Splash Zone + Atmospheric)

Zone	Protection Method	Minimum Thickness
Atmospheric (deck, railings)	Polyurethane topcoat + MIO intermediate + epoxy primer	280 μm total
Splash zone (tidal + 2 m above)	Glass flake epoxy (high build)	400 μm
Immersion zone (permanently underwater)	Coal tar epoxy or cathodic protection (sacrificial anodes)	500 μm + ICCP option

Optional Enhancements

Integrated monitoring system: Strain gauges, accelerometers, corrosion sensors, and tilt meters with real-time cloud dashboard
Solar-powered navigation lights: Class I or II marine lanterns with 10-year battery
Architectural LED lighting: RGBW fixtures programmed for seasonal or event-based color schemes
Bird deterrent system: Stainless steel spikes or tensioned wire on truss nodes
Fender system: Timber or composite pile clusters protecting piers from barge impact (400+ ton vessel rated)

Quality & Compliance

Design codes: AASHTO LRFD (US), Eurocode 3 (EU), BS 5400 (UK), or JTG D64 (China) — client's choice
Fabrication tolerance: EN 1090-2 Class EXC3 or AWS D1.5 (Bridge Welding Code)
Load testing: Proof load to 1.25 × design live load before opening
Warranty: 10-year structural warranty + 25-year coating performance guarantee (routine inspection required)