Spiral Steel Pipe for Bridge Engineering

Spiral steel pipe for bridge engineering is a special pipe made of hot-rolled high-strength steel coil by continuous spiral forming and double-sided submerged arc welding.It is an ideal material for core structures such as pile foundation,pier column and arch rib in modern bridge construction,and is suitable for all kinds of complex working conditions such as crossing rivers,seas and highways.

This kind of steel pipe has outstanding mechanical properties.Low alloy steels such as Q355B and Q420C are commonly used.The yield strength is above 355MPa,and the tensile strength is over 500MPa.It has good plasticity and impact toughness.The spiral weld is distributed at 45-70,and the stress is transmitted evenly.The circumferential stiffness is 15%-20%higher than that of the straight-seam steel pipe,which can effectively resist the cyclic load of vehicles,strong wind and earthquake.The fatigue life of the weld is more than 2 million times after 90%ultrasonic and X-ray flaw detection,which meets the long-term service requirements of the bridge.

Flexible specification customization,pipe diameter ranging from hundreds of millimeters to several meters,wall thickness of 6-25mm can be adjusted as needed,which can accurately match different geological and load conditions;Hollow structure is convenient for pile foundation grouting,greatly improving side friction and end bearing capacity,especially suitable for complex foundations such as soft soil and silt.

The anti-corrosion technology is mature,and the treatment schemes such as 3PE coating,epoxy powder and epoxy coal tar pitch can cope with the coastal high salt fog and groundwater corrosion environment,and significantly prolong the service life of the structure.The characteristics of factory prefabrication and quick on-site assembly welding can shorten the construction period,reduce the risk of aerial work and reduce the comprehensive construction cost.

Nowadays,from urban interchanges to large-scale cross-sea bridges,spiral steel pipes for bridges have become the key materials to promote the high-quality development of transportation infrastructure by virtue of their comprehensive advantages of high strength,high adaptability and high durability.