The arch system typically includes an arch unit, a spandrel wall, and a wing wall.
- The spandrel walls run parallel to the arch, retaining the backfill at each end of the structure, and enhancing its appearance. Units range from 6m to 21m span.
- The wing walls are placed at each end of the spandrel wall to retain the backfill, support the spandrel walls, and to provide retaining walls. Wing walls orientation can be designed to suit site specific requirements. Each wing wall unit is approximately 2.5m wide.
Humes also offer a bevelled end solution which provides an alternative to the spandrel and wing wall arrangement. While this design can improve the appearance of the arch system, the construction can be more complex.
All of these elements may be finished in either conventional concrete or a variety of applied finishes to suit the design requirements.