What is steel support? What are the usage scenarios

2025-08-29 15:18:19

1、 Definition and core characteristics of steel support

Steel support is a rigid support component made of high-strength steel (such as Q235, Q355, etc.) through welding or bolt connection. Common forms include steel pipe support, H-beam support, composite steel support, etc. Its core features are:

1. High bearing capacity: The yield strength is usually above 235MPa (refer to GB/T 700-2006 standard), which can withstand large axial pressure and lateral loads;

2. Lightweight: Compared to concrete supports, it reduces weight by 30% -50%, making it easier to transport and install;

3. Reusable: Temporary supports can be disassembled and reused to reduce project costs;

4. Quick construction: Standardized components can achieve mechanized and rapid installation, shortening the construction period.

2、 The main usage scenarios of steel supports

1. Construction engineering

-Deep foundation pit support: In excavations deeper than 5 meters (such as high-rise building basements), steel supports and retaining piles are combined to form an internal support system to prevent soil collapse. For example, the foundation pit of Shanghai center Building is supported by φ 609mm steel pipes with an interval of 4m and a design axial force of 4000kN (data source: Technical Specification for Building Foundation Pit Support JGJ 120-2012).

-Temporary support for large-span structures: During the construction of steel structure factories or sports venues, steel supports are used for temporary reinforcement of overhanging parts.

2. Underground engineering

-Tunnel construction: Steel supports are commonly used to control the deformation of surrounding rock in shield tunneling starting shafts and underground subway sections. For example, some sections of Shenzhen Metro Line 14 are supported by double spliced H-beams with a spacing of 1.5 meters and a pre added axial force of 200kN.

-Mining tunnels: During underground operations, steel supports can replace traditional wooden supports and improve safety factors.

3. Bridges and Municipal Engineering

-Bridge jacking construction: Steel supports are used as temporary pier columns to support the sliding of bridge segments;

-Reinforcement of old buildings: Adding steel supports to brick concrete structures to enhance seismic performance, such as the angle steel support system recommended in the Technical Code for Seismic Reinforcement of Buildings JGJ 116-2009.

3、 Technical parameters and selection points

The design of steel supports requires comprehensive consideration of factors such as load, span, and geological conditions, with key parameters including:

-Section size: The commonly used steel pipe support has an outer diameter of φ 300mm - φ 800mm and a wall thickness of 8mm-20mm;

-Slenderness ratio limit: According to GB 50017-2017 "Design Standard for Steel Structures", the slenderness ratio of compression members should not exceed 150;

-Connection method: Flange bolt connection is suitable for scenarios that require frequent disassembly and assembly, while welding is used for long-term support.