I. Core Function: The "Steel Guardian" of Engineering Safety
Steel struts, short for steel structural supports, are primarily constructed using materials like steel pipes and H-beams. They can be classified into various types based on layout, such as cross struts, corner struts, and inclined struts. Their core function is to balance the pressure difference between the inside and outside of an excavation to prevent structural deformation and collapse. In subway construction, they act like the "ribs" of a tunnel, resisting surrounding rock pressure. In deep excavation projects for high-rise buildings, they erect a temporary shoring system to safeguard the construction of underground structures. In bridge construction, they serve as temporary supports to ensure the precision of concrete pouring.
Compared to traditional concrete supports, steel struts offer significant advantages: installation and removal efficiency is increased by over 30%, significantly reducing the exposure time of the unsupported excavation; they can be reused and recycled 5-8 times, with some intelligent products having a service life exceeding 10 years, substantially lowering project costs; their modular design allows them to adapt to diverse needs, ranging from ordinary foundation pits to large-span projects exceeding 40 meters. However, traditional steel struts also have limitations, such as relatively lower rigidity and stability, which has driven the need for technological iteration and upgrades.
II. Technological Innovation: From Traditional Shoring to Intelligent Empowerment
In recent years, China's steel strut technology has achieved leapfrog development, with three major innovative technologies becoming mainstream in the industry:
Automatic Axial Force Compensation Self-Adaptive Technology: This technology uses a hydraulic servo system to monitor axial force and displacement in real-time, providing early warnings (up to 72 hours in advance) for structural instability risks with an accuracy rate of 86.4%. It has been applied in major projects like the Beijing Sub-Center.
Prefabricated Pre-stressed Fish Belly Beam Technology (IPS Method): By using the pre-tightening force of steel strands to reduce structural bending moments, this method significantly enhances the rigidity of the support system. It creates more open construction space and shortens the project timeline by 30%-40%.
HIS High-Capacity Tool-Type Support System: Independently developed by China Construction Eighth Engineering Division Corp., this system enables "building block" style rapid assembly. A 40-meter support can be erected in just 8 steps, with a single set having an ultimate load-bearing capacity of 150 tons. It has demonstrated outstanding performance in ultra-hazardous projects like the Tongzhou Bay utility tunnel.
Technological upgrades are also driving improvements in product quality. Current high-quality steel struts feature a yield strength ≥ 235 MPa and tensile strength ≥ 375 MPa. After hot-dip galvanizing, their corrosion-resistant lifespan can exceed 30 years. Dimensional accuracy is controlled within ±3 mm, and the non-destructive testing (NDT) pass rate for welds is 100%. The application of BIM technology and parametric modeling has further improved component production precision to ±1.5 mm, with an ex-factory pass rate exceeding 99.2%.
Looking ahead, as intelligence, modularization, and lightweighting become the main axes of technological evolution, steel struts will find even wider application in areas like underground utility tunnels and new types of infrastructure.
