Steel Structure buildings have become an important choice for modern seismic resistant buildings due to their light weight, high strength, and good ductility. However, the seismic performance of steel structures is not solely determined by the materials themselves, but depends on the collaborative optimization of multiple dimensions such as structural design, node construction, material performance, and construction quality. This article systematically elaborates on the core strategies for improving the seismic performance of steel structure buildings from five aspects: design philosophy, construction technology, material selection, construction technology, and maintenance management.

1、 Structural design: with "ductile energy dissipation" as the core concept

1. Reasonably choose the structural system

The seismic resistance of steel structures first depends on the rationality of the structural system. Common seismic resistant structural systems include:

Frame structure: dissipates seismic energy through plastic deformation of beam column nodes, suitable for mid to low rise buildings;

Frame support structure: adding central or eccentric supports (such as buckling restrained braces BRB) to significantly improve lateral stiffness;

Tube structure: using a combination of steel frame and concrete core tube, suitable for super high-rise buildings.

Research has shown that buildings using a dual lateral force system (such as a frame support system) improve their seismic performance by over 40% compared to a single system.

2. Optimize stiffness distribution and quality configuration

Uniformization of stiffness: To avoid sudden changes in floor stiffness (such as the "weak layer" phenomenon in the upper floors of residential buildings), continuous vertical support or reinforced transfer layer design should be adopted;

Quality eccentricity control: Simulate quality distribution through BIM models to reduce torsional effects and ensure coordinated deformation of the structure during earthquakes.

3. Energy consumption mechanism design

The principle of strong columns and weak beams: By adjusting the cross-sectional dimensions and reinforcement of beams and columns, ensure that the beam end forms a plastic hinge before the column end to avoid overall collapse;

Energy dissipation component integration: Metal dampers, friction pendulum supports and other energy dissipation devices are added to non load bearing parts, which can absorb 30% -50% of seismic energy.

2、 Node Construction: From "Rigid Connections" to "Intelligent Nodes"

1. Node ductility design

The failure of steel structure nodes often leads to the collapse of the overall structure. The key measures include:

Strengthening of stiffeners: setting stiffeners in the connection area between beams and columns to prevent local buckling;

Dog bone weakening (RBS): Cutting arc-shaped notches at the flange of the beam end to guide the plastic hinge to move outward and protect the node weld seam;

Bolt welding hybrid connection: Combining high-strength bolt friction type connection with the reliability of weld seam to improve node ductility.

2. Application of new node technology

Self resetting node: using prestressed steel strands or shape memory alloys (SMA) to restore the node to its original state after an earthquake;

Removable energy consuming components: Removable energy consuming steel plates are installed at the nodes for quick replacement after earthquakes, reducing repair costs.

3、 Material Properties: Breakthroughs in High Strength Steel and Intelligent Materials

1. Application of high-strength steel

By using high-strength steel such as Q460 and Q690, the cross-sectional size of components can be reduced by 20% -30%, the self weight of the structure can be lowered, and thus the seismic inertial force can be reduced;

Low yield point steel (LYP100, yield strength 100MPa) is used for energy dissipation components, and its high ductility (elongation ≥ 40%) can significantly improve energy dissipation capacity.

2. Innovation in smart materials

Weathering steel: By adding elements such as copper and chromium, the corrosion resistance is improved by 5-8 times, extending the structural life;

Carbon Fiber Reinforced Polymer (CFRP): used for local reinforcement, with a tensile strength up to 10 times that of steel and a weight of only 1/5.

4、 Construction technology: precision control and quality assurance

1. Factory prefabrication and assembly construction

Components are processed by CNC in the factory, with dimensional errors controlled within ± 2mm to reduce on-site welding deformation;

Using BIM technology for pre assembly to solve complex node space conflicts and ensure installation accuracy.

2. Welding and testing technology upgrade

Robot welding: Automated welding is used for key welds (such as box column partition welds), with a one-time pass rate of over 99%;

Non destructive testing: Comprehensive use of ultrasonic (UT) and radiographic (RT) testing to ensure that the weld seam is free of defects such as cracks and incomplete fusion.

3. Anti corrosion and fire prevention treatment

Hot dip galvanized layer thickness ≥ 85 μ m, ensuring a 50 year anti-corrosion cycle;

Expansion type fireproof coating forms a 30-50mm insulation layer when exposed to fire, meeting a 2-hour fire resistance limit.

5、 Maintenance management: Full lifecycle performance monitoring

1. Health monitoring system

Install fiber Bragg grating sensors in key areas to monitor stress, deformation, and vibration frequency in real-time;

By combining AI algorithms, the accuracy of warning structural damage (such as bolt loosening and weld cracking) can reach over 90%.

2. Regular testing and reinforcement

Conduct a comprehensive inspection every 5 years, with a focus on node areas and corrosion conditions;

External steel reinforcement or carbon fiber cloth wrapping is used to restore the load-bearing capacity of damaged components.

6、 Case Study Inspiration: Drawing on Japanese Experience

As a country with frequent earthquakes, Japan's steel structure seismic technology is worth referring to:

Mandatory regulations require all steel structure buildings to undergo "ultimate bearing capacity calculation" and "time history analysis";

Technological innovation: Promote the use of buckling restrained braces (BRBs) and seismic isolation bearings to reduce seismic forces by 60% -70%;

Public education: Regularly conduct earthquake drills to enhance the emergency response capabilities of building users.

conclusion

Improving the seismic performance of steel structure buildings is a systematic project that needs to run through all aspects of design, construction, and operation and maintenance. In the future, with the popularization of intelligent materials, digital twin technology, and robot construction, the seismic resistance of steel structures will move towards a new stage of "perceptible, adjustable, and self-healing". Through technological innovation and standardized improvement, steel structures are expected to become one of the most reliable building forms for responding to earthquake disasters.

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