The Shapes And Types Of Corrugated Pipe Culvert

1.1.The shapes of corrugated pipe culvert

Steel corrugated pipe culvert is made of corrugated thin steel plate,which is 2.0-8.0mm thick, then be made into pipe sections or plates to increase its stiffness and resistance to axial pressure. with this method, the pipe is is called a corrugated pipe culvert or corrugated plate channel. Steel plate material: SS400 (Q235) hot steel plate.

Hot dip galvanizing treatment (average thickness ≥ 84 microns,<600g/m2>. Asphalt is added during construction.) Product technical parameters: Package type 1 (diameter 0.5-1.2m) with a wave spacing of 125mm and a wave height of 25mm,Assembly type 2 (diameter 1.5-2.5m) with a wave spacing of 200mm and a wave height of 55mm. Assembly type (diameter 2.0-8.0m) with a wave spacing of 200mm and a wave height of 55mm.

Compared to reinforced concrete structures, corrugated pipe culverts has advantages of light weight, Easy to transport and store, simple construction process, fast assembly, short construction period and other advantages.

Steel corrugated pipe culvert is one kind of soft structure, it has some seismic capacity, and it can adapting to significant settlement and deformation. After the corrrugated pipe is completed construction on site , it forms a composite structure with the surrounding soil to jointly bear the force. The backfill soil on the wedge-shaped part and both sides of the corrugated pipe culvert is crucial. If the backfill is not dense or there are hollow wedge-shaped parts or large stones directly acting on the pipe body, there will be significant deformation or protrusion in some areas, which poses a safety hazard and may even cause quality accidents. Therefore, the backfill soil on both sides and wedge-shaped parts of the corrugated pipe culvert should be strictly controlled during construction.

Due to the current situation of large loading vehichles, research institutions and experts in steel corrugated pipe culverts have made mechanical calculations on existing corrugated pipes with diameters ranging from 1.0-6.0m,Based on theory and practice, a fill height comparison table for the corrugated pipe culvert has been compiled for different pipe diameters, wall thicknesses, and soil cover thicknesses. The brief design content as bellow:

For fully assembled corrugated culvert pipe: waveform parameters: wave spacing and wave height of 125 * 25mm when the diameter is 0.5-1.25m; When the diameter is 1.5-2.5m, the wave distance and wave height are 200 * 55mm; Standard span: 0.5m.075m 1.0m 1.25m 1.5m 2.0m 2.5m (tubular structure, connected by flange up and down or axial bolts)

For Assemble corrugated pipe, waveform parameters: when the diameter is 2.0-8.0m, the wave distance and wave height are 200 * 55mm; Standard span: 2m, 3m, 4m, 5m, 6m, 7m, 8m (assembled in sheet form and connected by overlapping bolts between plates). Material design and requirements for hydraulic calculation and aperture section shape of culverts: anti-corrosion design: hot-dip galvanized product surface, and asphalt coating on construction site. Design foundation and backfill design for inlet and outlet and connection, as well as road surface design for internal channels,

Design Overview: Portal Structure Form:

-Bazi style, end wall style, conical slope style, straight wall style, twisted slope style, flat head style, corridor style, streamlined style

Commonly used: Bazi style, end wall style, corridor style, flat head style.

2.The anti corrosion of corruagated pipe culvert

For corrugated pipe culverts, the outer side is mainly affected by soil corrosion, while the inner side is mainly affected by water corrosion and atmospheric corrosion.The corrosion mechanism of soil is in the range of strong corrosion and moderate corrosion in various types of soils in China under normal moisture conditions.

When our steel corrugated pipe culvert leaves the factory, the pipe sections and plates are all hot-dip galvanized, and the average thickness of the galvanized layer is greater than 84um. In the absence of salt alkali water or harmful industrial wastewater, the galvanized layer can prevent corrosion and the service life can reach 60-80 years. According to the survey, the annual corrosion thickness of the non galvanized iron pipe wall is generally 0.01-0.03mm. Currently, before leaving the factory, the thickness of the pipe wall of our culvert increases by 0.5mm compared to normal use, and it can increase the service life of 25-50 years. In addition, after the pipe culvert is transported to the construction site, it is coated with asphalt twice on the construction site, and the asphalt coating thickness reaches 0.4mm-0.5mm, which can increase its service life by 5-15 years,In addition, we have adjusted the technical parameters of the corrugated pipe culvert (wave distance, wave depth, wall thickness) and increased the safety factor for the use of corrugated pipe culverts in China. Therefore, the service life of steel corrugated pipe culverts can fully reach or exceed 100 years.