Product Description

Introduction

A steel truss bridge is a structural system between a beam bridge and an arch bridge. It integrates a flexural upper beam structure with compression-bearing lower columns as a whole. Due to the rigid connection between beams and columns, the beam is unloaded by the flexural stiffness of the columns, making the entire system a bending-compression structure with thrust.

Applications

It is generally used for urban bridges, highway viaducts and overpasses with small spans.

Reinforced concrete: Small to medium spans

Prestressed reinforced concrete: Long spans

Straight-legged rigid frame (portal type) and inclined-legged rigid frame: Small to medium spans

T-shaped rigid frame and continuous rigid frame: Long spans

Case 1: Shanghai-Nanjing Highway Bridge

This bridge is a simply supported steel truss structure with a span of 80 m,a height of 11m,and a distance of 21.5m between the two trusses.

Steel plates with 50 mm thickness (max)were used.The deck is composed of reinforced concrete slabs, transverse beams,and longitudinal girders.

Case 2: Ring Expressway Bridge in Zunyi

The length of the bridge is 682 m.It has eight units,the third of which is a truss on a vertical curve with radius of 4800m.

This  truss  has  two  spans,i.e.85m,and  81  m.The  deck  is 49 m wide.There are 11 primary trusses and one transverse truss at each pier.There are a total of four transverse trusses. The primary trusses were welded in the shop and connected together in the field using high-strength bolts.Grade Q370qD steel was used in this bridge.

Case 3: Fengxiang Road Steel Truss Bridge in Wuxi

The steel truss bridge of Contract Section FXB02 for the Fengxiang Road Rapid Reconstruction Project in Wuxi adopts triangular trusses without vertical web members, with a span arrangement of 165+90m, a truss height of 14m, a three-main-truss structure, and a total width of 40m. 

The 165m main span crosses the Shanghai-Nanjing Expressway, with a total steel consumption of approximately 7,800 tons.

Advantages

• Strong span adaptability: A single span can cover 80-180m, and multi-span continuous arrangement can achieve a total length of over 500m. It requires no excessive piers, reducing reliance on underwater geology.

• High construction efficiency: Segmental prefabrication in the factory (single segment weight: 50-150 tons), with on-site cantilever assembly or integral hoisting.

• Low maintenance cost: The truss structure has clear force transmission paths, and components can be inspected and replaced individually. Fluorocarbon paint is adopted for the anti-corrosion coating, extending the maintenance cycle to 8-10 years.

Delivery

FAQ

Q1: Is large-scale scaffolding required for the on-site installation of steel truss bridges? Does it have a significant impact on existing traffic?

A1: There are two types of installation methods:

① Scaffolding assembly (suitable for non-navigable areas with low traffic volume);

② Scaffold-free cantilever assembly (suitable for busy traffic routes and navigable waterways). Cantilever cranes are used for segmental assembly, with only temporary supports set at piers, resulting in no traffic disruption.

Q2: What is the anti-corrosion service life of steel truss bridges? Which parts require focused attention during later maintenance?

A2: The anti-corrosion service life depends on the environment and coating system:

① Ordinary atmospheric environment (e.g., urban expressways): "Epoxy zinc-rich primer (80μm) + epoxy micaceous iron oxide intermediate coat (120μm) + fluorocarbon topcoat (60μm)" with a service life of 15-20 years;

② Marine/high-humidity environments: An additional epoxy glass flake intermediate coat (100μm) is added, extending the service life to 20-25 years.

Key maintenance points:

① Joints (prone to corrosion due to dust and water accumulation) – inspect coating adhesion every 5 years;

② High-strength bolts – test torque every 10 years and retighten if torque loss ≤10%;

③ Connections between web members and chord members – prevent welding cracks.