The largest corrugated pipes and fittings factories in Egypt

Diameters ranging from 100 mm up to 2500 mm

Corrugated features

SEIF AL NASR provides a comprehensive range of corrugated products, including pipes, fittings, manholes, and chambers, with internal diameters ranging from 100 mm up to 2500 mm. The company also offers various ring stiffness classes designed to suit different soil conditions, installation depths, excavation widths, and groundwater levels. Ring stiffness specifications are either provided by project consultants or carefully designed by SEIF AL NASR’s engineering team to ensure optimal performance and reliability.

Structural Behaviour of Flexible Pipes in Soil

When a flexible pipe, such as an HDPE profiled pipe, is subjected to vertical soil loads, it undergoes slight deflection. This deformation generates horizontal soil pressure that acts as a support. When the vertical and horizontal pressures are nearly equal, the load distribution around the pipe resembles a hydrostatic condition. In this state, the pipe wall is mainly subjected to circumferential (hoop) compressive stresses.

With increased burial depth, there is a higher risk of buckling. However, as the pipe deflects under vertical load, it mobilizes passive soil resistance along its sides. This interaction results in a ring deflection that significantly reduces the vertical load on the pipe itself. Instead, the load is transferred to the surrounding soil, which forms a natural arching effect over the pipe. In essence, when a flexible pipe like HDPE is buried, the pipe and the surrounding soil form a composite structure, working together to distribute loads and maintain system integrity.