There are a lot of arch-shaped products and structures around us.As representative examples, there are arch bridges and tunnels made with a variety of materials and even our feet have arches that support our body.

As such, the technology applying the benefits of the arch structure that increases resistance to external loads with its own shape to temporary earth retaining (sheathing) wales to support underground excavation sides is the TAW(Tied Arch Wale) method.

Application of arch shape and effects

Based on the background theory, the purpose of the development of the TAW method by improving the existing Strut method is as follows:

The behavior of the TAW(Tied Arch Wale) method is same as arch bridges to which external load acts.

The TAW method increases resistance to earth pressure because TAW has arch member which is opposite shaped with the moment-shaped curve produced by the earth pressure.

In addition, just like the theory that arc-shaped member with uniform distributed load is generating only the axial force in the section of the member, TAW has an effect of effectively distributing earth pressure acting to the wale.

Accordingly, the TAW method can allow the spacing of struts which was 2-3 meters in the existing Strut method to be widened to more than 9 meters.

When TAW is carried or handled, the steel bars fixed on both ends of the arch member make the shape maintained and contribute to increase the load carrying capacity of TAW by increasing the resistance of the arch member upon the earth pressure.