What are the construction techniques for steel bridges?

2025-03-27 16:34:07

The construction technology of Steel Structure bridge integrates the comprehensive achievements of material science, mechanical engineering and digital technology, and its core lies in realizing the goal of efficient, precise and safe construction. The following are the current mainstream steel bridge construction technology classification and key technical points:

I. Component processing and manufacturing technology

CNC cutting and automatic welding

CNC plasma/flame cutting machine is adopted for high-precision plate undercutting, and the error can be controlled within ±1mm.

Welding robot to realize the U-rib, bulkhead and other key parts of the fully automated welding, such as Shanghai-Sutong Yangtze River Bridge using six-axis robots to complete the weld depth of 8mm process breakthrough.

3D printing of shaped components

For complex nodes (such as curved anchor box, multi-directional bearing), the use of metal additive manufacturing technology, Chongqing Baijusi Bridge 3D printed steel components to reduce traditional processing waste by 40%.

Weathering steel surface treatment technology

Applying nano-composite coating or thermal spraying aluminum-zinc alloy, the steel structure of Yangsigang Bridge in Wuhan has a corrosion-resistant life of 100 years, eliminating the need for traditional painting maintenance.

II. Structural Installation Core Technology

Modularized overall lifting

The use of 10,000-ton floating cranes (such as “Zhenhua 30”) for the overall installation of super-large steel box girders, the Shenzhen-Zhongshan Corridor 4,000-ton module lifting in a single operation, shortening the sea operation time by 70%.

Jacking Construction Method

The hydraulic jacking system pushes the steel girders forward in segments, which is applicable to the construction of cross-line bridges. Hangzhou-Ningbo High-Speed Railway Cross-sea Bridge adopts multi-point synchronized jacking technology, and the pushing distance reaches 12 meters in a single day.

Cantilever assembly technology

Utilizing bridge tower crane for symmetrical cantilever construction, the precision of steel box girder section assembling of HZMB reaches 3mm level error control.

Connection and Reinforcement Technology

Friction-type connection with high-strength bolts

Use 10.9 grade high-strength bolts (such as HSL-4 type) to realize rigid connection of nodes through pre-tensioning force, with anti-slip coefficient ≥ 0.45.

Intelligent welding monitoring system

Equipped with a welding quality monitoring system of infrared thermal imaging and ultrasonic flaw detection, the real-time detection of weld defects increases the one-time pass rate of weld seams on Hsu-Su-Tong Bridge to 99.8%.

Self-resetting energy-consuming nodes

Replaceable damper nodes are used in seismic design, such as the BRB support node of a bridge in Xiong'an New Area, which can absorb seismic energy of magnitude 8.

Fourth, digital construction technology

BIM full life cycle management

Establishing digital archives of steel components, the Hong Kong-Zhuhai-Macao Bridge project resolved 136 design conflicts in advance through BIM modeling, reducing rework losses of more than 20 million yuan.

Laser Scanning Positioning System

Adopting Leica MS60 multi-station for millimeter-level positioning, and cooperating with BeiDou navigation to realize automatic airborne deviation correction of large components.

Digital twin real-time monitoring

5000+ sensors are installed to monitor stress and deformation data, and the response time for structural safety warning during the construction of Shenzhen-Zhongshan Corridor is shortened to 10 seconds.

V. Green Construction Technology System

Assembled Temporary Structure

Using standardized steel trestle bridge and platform module, the reuse rate of temporary facilities of Guangshen Yanjiang Expressway Project reaches 85%.

Photovoltaic-driven welding station

With the integration of photovoltaic power generation system at the construction site, the welding station of Nanjing Five Bridges Project realized 40% self-sufficiency in power.

Carbon Footprint Intelligent Control

Carbon emission monitoring platform based on Internet of Things accurately tracks energy consumption in transportation, welding, etc., reducing carbon emissions per unit of output value by 32% in one project.