Project overview
This project is the concept structural design for a causeway and floating bridge to Ramhan Island in the UAE. Wrenze Steel prepared the concept for the client, QA Construct Contracting L.L.C.
The 3D model on this page shows one of the steel truss spans studied for the crossing: a long box truss with top and bottom chords tied together by diagonals. The concept package also covered typical cross sections through the causeway embankment and a site plan showing the route of the crossing over the water.
Our scope
Our scope was concept structural design. At this stage the aim is to prove the scheme works and to give the client a sound basis for pricing and the next design stage. Typical concept tasks include:
- choosing the structural system for each part of the crossing;
- setting the main loads, including traffic, wind and water effects;
- sizing the main members to a level that supports early quantities and cost;
- identifying the risks and questions that detailed design must answer.
The structure
The crossing combines three types of structure, and each works in its own way.
A causeway is a raised embankment of fill and rock armour that carries the road on solid ground across shallow water. It is simple and durable, but it blocks water flow, so openings or bridge spans are often needed along its length.
A truss span carries load through a triangulated frame. The top and bottom chords take compression and tension, and the diagonals carry shear between them. Trusses are light for their depth, which suits long spans and makes the steel easier to transport and lift.
A floating bridge rests on pontoons and rises and falls with the water level. The main design questions are buoyancy, stability against tilting, and the links between the floating part and the fixed causeway, which must allow the movement without overloading either side.
See our other bridge projects, read about our structural engineering consultancy service, or request a quote for your concept design.
