I. Core Advantages of Seismic Steel Structure Bridges

High ductility seismic design

Ductile node: adopting dog-bone weakening (RBS) or end-plate strengthening node, plastic corner ≥0.03rad, energy consumption capacity increased by 50%;

Multiple lateral-resistant system: frame-braced combination design, lateral stiffness increased by 40%, meeting 8-9 degree seismic defense requirements.

Light weight and high strength materials

2Q420qE bridge steel: yield strength ≥420MPa, 25% weight reduction compared with traditional steel, reducing seismic inertia force;

Weathering-resistant steel (Q345qNH): 8 times higher corrosion resistance and painting-free maintenance for the whole life cycle.

Intelligent seismic damping technology

Buckling Restrained Brace (BRB): axial deformation ±50mm, single energy consumption ≥800kJ;

Friction Pendulum Support (FPS): friction coefficient 0.03-0.05, horizontal displacement capacity ±500mm;

Viscous damper: force range 1,000-10,000kN, damping efficiency ≥40%.

Fast construction and long life

Modular prefabrication: maximum section lifting weight of 3,000 tons, 40% shorter construction period;

Design life ≥100 years, replaceable dampers and bearings, maintenance cost reduced by 60%.

II. Core product series and technical parameters

III. Key Seismic Technologies

Node and connection technology

High-strength bolt connection: 10.9S grade bolts, preload error ≤±5%, anti-slip coefficient ≥0.45;

Full-penetration weld: bevel K-type design, UT flaw detection Ⅰ qualified rate ≥ 99.5%.

Structural system innovation

Elastic constraint system: the bridge pier and girder adopt elastic connection to release temperature deformation and reduce seismic force;

Self-resetting bridge tower: SMA energy dissipators are set at the bottom of tower columns, which automatically restore the original position after earthquake.

Intelligent monitoring and early warning

Fiber grating sensor: real-time monitoring of stress and displacement with accuracy ±1με;

AI health diagnosis system: machine learning-based prediction of damage location, accuracy ≥95%.

IV. Material and Manufacturing Process

Application of special steel

Low yield point steel (LY160): yield strength of 160MPa, elongation ≥ 40%, used for energy-consuming components;

Fire-resistant steel (Q345FR): 600 ℃ high temperature strength retention ≥ 65%, to protect structural safety under fire.

Precision processing technology

Three-dimensional CNC cutting: precision of ±0.5mm for coherent line cutting, bevel angle error ≤0.5°;

Robot welding: four-wire submerged arc welding molding 50mm thick plate at one time, heat input ≤2kJ/mm.

Anti-corrosion and fire prevention

Arc spraying aluminum: 200μm aluminum layer + 80μm epoxy sealer, salt spray resistance ≥ 20,000 hours;

Intumescent fireproof coating: thickness 2.5mm, fire resistance limit ≥2 hours (GB 14907).