What are the advantages of box section steel structures in construction?

2025-03-26 16:09:05

As an important component of the modern building structure system, box section Steel Structure, by virtue of its unique cross-section form and mechanical properties, shows significant advantages in ultra-high-rise, large-span and heavy-duty buildings. This kind of closed member welded by four steel plates is reshaping the paradigm of architectural design and construction through the combination of mechanical property optimization and industrialized production.

I. Excellent Mechanical Properties

Advantage of torsional stiffness

The closed cross-section feature of box-type steel structure makes its torsional moment of inertia 8-12 times that of H-type steel. The core cylinder of a 380-meter super high-rise building adopts box-type steel columns, and the torsion angle at the top of the structure is controlled within 0.002rad, which meets the requirements of ISO 3010 seismic code. When the section width/thickness ratio is optimized to 15:1, the local stability coefficient is improved to 2.3, which is significantly better than that of open section.

Bidirectional load carrying capacity

The section modulus balance of box section steel structure in X/Y axial direction reaches more than 95%. A convention and exhibition center project adopts 1.2m×1.8m box section steel beams to realize 72m column-free space span, and the deflection in the span is only L/850 (L is the span), which reduces the steel consumption by 18% compared with that of H-type steel scheme.

Advantages of industrialized construction

High degree of prefabrication

More than 90% of the processing procedures of box-type steel structure are completed in the factory, and an assembled residential project adopts standard box-type steel components, with the on-site installation efficiency reaching 120 tons/day, which shortens the working period by 45% compared with cast-in-place concrete structure. Intelligent welding production line controls the dimensional tolerance of the components to ±1.5mm, ensuring the precision of modular assembly.

Construction cycle compression

A data center adopts box-type steel frame system, and the main structure of 50,000 square meters building was topped out in only 58 days. The all-bolt connection node technology shortens the lifting cycle of a single-story 2,000 square meter building to 3 days, which is 60% faster than the traditional welding construction.

Space Efficiency Enhancement

Optimization of cross-section size

Under the same load bearing capacity, the section height of box-type steel structure can be reduced by 30% compared with H-type steel. A commercial complex project through the 0.8m × 0.6m box-type steel columns instead of 1.2m × 0.8m concrete columns, releasing the commercial space area of 1200 square meters, equivalent to 10% increase in rental income.

Piping integration design

The cavity of box-type steel structure can be integrated to arrange HVAC, electrical lines and other equipment. An intelligent office building has pre-buried intelligent control system pipelines in 0.9m×1.5m box-type steel beams, which reduces the floor height by 0.6m and the building energy consumption by 12%.

IV. Economic Advantages

Material Utilization Rate Enhancement

When the box-type steel structure adopts variable cross-section design, the amount of steel used can be reduced by 25% compared with equal cross-section H-beam. A bridge project saves 1,500 tons of steel and reduces direct cost by 18% through the gradual change of box section steel beam (0.6-1.2m height change).

Full Life Cycle Cost

Calculation of a stadium project shows that the maintenance cost of box section steel structure is only 1/3 of that of concrete structure, and the comprehensive cost of 50-year full cycle is reduced by 42%. The combination of fireproof coating and weathering steel extends the maintenance cycle to 25 years.

V. Seismic and safety performance

Nodal energy consumption capacity

The hysteresis curve of through node of box-type steel structure partition is full under cyclic load, and a laboratory test shows that its energy dissipation coefficient reaches 0.38, which is 2.1 times of common node. The application of this node in a high-rise building in an 8-degree seismic zone reduces the degree of structural damage by 60%.

Fire performance optimization

The cavity of box-type steel structure can be filled with fireproof material to form a composite cross-section. A transportation hub project adopts ceramic fiber-filled box-type steel columns, which raises the fire resistance limit to 3 hours and reaches the highest fire resistance level stipulated in GB 50016.