News - Steel Structure: A Key Structural System in Modern Engineering

In contemporary architecture, transportation, industry, and energy engineering, steel structure, with its dual advantages in both material and structure, has become a core force driving innovation in engineering technology. Using steel as its core load-bearing material, it transcends the limitations of traditional structures through industrialized production and modular installation, providing efficient solutions for a wide range of complex projects.

Advantages and Disadvantages of Steel Structure - CHINA ROYAL STEEL

Definition and Nature of Steel Structure
Steel structure refers to a load-bearing structural system composed of steel plates, steel sections (H beams, U channels, angle steel , etc.), and steel pipes, secured through welding, high-strength bolts, or rivets. Its essence is to leverage steel's high strength and toughness to evenly transfer vertical loads (deadweight and equipment weight) and horizontal loads (wind and earthquakes) from a building or project to its foundation, ensuring structural stability. Compared to concrete structures, the core advantage of steel structures lies in their mechanical properties: their tensile strength can reach over 345 MPa, more than 10 times that of ordinary concrete; and their excellent plasticity allows them to deform under load without breaking, providing a double guarantee of structural safety. This characteristic makes them irreplaceable in large-span, high-rise, and heavy-load scenarios.

Main Types of Steel Structures

(I) Classification by Structural Form
Gateway Frame Structure: This structure, composed of columns and beams, forms a "gateway"-shaped framework, coupled with a supporting system. It is suitable for industrial plants, logistics warehouses, supermarkets, and other structures. Common spans range from 15 to 30 meters, with some exceeding 40 meters. Components can be prefabricated in factories, allowing on-site installation in just 15 to 30 days. For example, JD.com's Asia No. 1 Logistics Park warehouses primarily utilize this type of structure.
Truss Structure: This structure consists of straight rods connected by nodes to form a triangular or trapezoidal geometry. The rods are subjected only to axial forces, fully utilizing the strength of the steel. Truss structures are commonly used in stadium roofs and bridge main spans. For example, the renovation of the Beijing Workers' Stadium employed a truss structure to achieve a 120-meter column-free span.
Frame structures: A spatial system formed by rigidly connecting beams and columns offers flexible floor plans and is the mainstream choice for high-rise office buildings and hotels.
Grid structures: A spatial grid composed of multiple members, often with regular triangle and square nodes, offers strong integrity and excellent earthquake resistance. They are widely used in airport terminals and convention centers.

(II) Classification by Load Characteristics
Flexural members: Represented by beams, these members withstand bending moments, with compression at the top and tension at the bottom. They often use H-sections or welded box sections, such as crane beams in industrial plants, and must meet both strength and fatigue resistance requirements.
Axially loaded members: These members are subject only to axial tension/compression, such as truss tie rods and grid members. Tie rods are designed for strength, while compression rods require stability. Circular tubes or angle steel sections are typically used. Eccentrically loaded components: These are subjected to both axial forces and bending moments, such as frame columns. Due to the eccentricity of the load at the beam ends, symmetrical cross-sections (such as box columns) are required to balance the forces and deformations.

Core Advantages of Steel Structures
(I) Excellent Mechanical Properties
High strength and low weight are the most significant advantages of steel structures. For a given span, the deadweight of a steel beam is only 1/3-1/5 that of a concrete beam. For example, a 30-meter span steel truss weighs approximately 50 kg/m, while a concrete beam weighs over 200 kg/m. This not only reduces foundation costs (by 20%-30%) but also mitigates seismic effects, improving the structure's seismic safety.
(II) High Construction Efficiency
Over 90% of steel structure components are prefabricated in factories with millimeter-level precision. On-site installation requires only hoisting and connection. For example, a 10-story steel office building takes only 6-8 months from component production to completion, a 40% reduction in construction time compared to a concrete structure. For example, a prefabricated steel residential project in Shenzhen achieved a construction speed of "one floor every seven days," significantly reducing on-site labor costs.
(III) Strong Earthquake Resistance and Durability
Steel's toughness enables steel structures to dissipate energy through deformation during earthquakes. For example, during the 2008 Wenchuan earthquake, a steel structure factory in Chengdu suffered only minor deformation and no risk of collapse. Furthermore, after anti-corrosion treatment (galvanizing and coating), steel can have a service life of 50-100 years, with maintenance costs far lower than concrete structures.
(IV) Environmental Protection and Sustainability
Steel recycling rates exceed 90%, allowing it to be re-smelted and processed after demolition, eliminating construction waste pollution. Furthermore, steel construction requires no formwork or maintenance, requiring minimal on-site wet work, and reducing dust emissions by over 60% compared to concrete structures, aligning with green building principles. For example, after the dismantling of the Ice Cube venue for the 2022 Beijing Winter Olympics, some components were reused in other projects, achieving resource recycling.

Widespread Application of Steel Structures
(I) Construction
Public buildings: Stadiums, airports, convention and exhibition centers, etc., rely on steel structures to achieve large spans and spacious designs.
Residential buildings: Prefabricated steel-structured residences are becoming increasingly popular and can meet personalized housing requirements.
Commercial buildings: Super-high-rise office buildings and shopping malls, which utilize steel structures to achieve complex designs and efficient construction.
(II) Transportation
Bridge engineering: Cross-sea bridges and railway bridges. Steel bridges offer large spans and strong wind and earthquake resistance.
Rail transit: Subway station canopies and light rail track beams.
(III) Industrial
Industrial plants: Heavy machinery plants and metallurgical plants. Steel structures can withstand the loads of large equipment and facilitate subsequent equipment modifications.
Warehousing facilities: Cold chain warehouses and logistics centers. Portal frame structures meet large-span storage requirements and are fast to construct and commission quickly.
(IV) Energy
Power facilities: Thermal power plant main buildings and transmission towers. Steel structures are suitable for high loads and harsh outdoor environments. New Energy: Wind turbine towers and photovoltaic mounting systems feature lightweight steel structures for easy transportation and installation, supporting clean energy development.