SOCOTEC Spain designs the new Ghazy al Gossaibi Mosque

The Ghazy al Gossaibi Masjid Project is located at the Mardumah Bay in the city of Jubail, in the Kingdom of Saudi Arabia. The architecture concept design defined a seashell roof and will represent a new iconic building at the corniche of the bay in Jubail.

The structural engineering concepts have been created by SOCOTEC Spain in conjunction with the architect and building services and civil engineers.

The structural challenge

The proposed structure comprises of longitudinal main arches with different curvature. The structural behavior of the arches will be a frame since the curvature is not linked with the funicular loads.

Due to the exterior and interior geometry design, some of the frames have two overlapped arches that create the roof and its cantilever in the front façade accommodating the roof openings. The horizontal reactions at the frames base are important, and a rigid base and foundation are considered.

The structural stability of the mosque is provided by steel frames in two orthogonal directions.

Additionally, a concrete core at the left side of the building and some steel braces are also used for the horizontal stability against wind, seismic and lumped loading.

Due to the complex design of the steel structure, the profiles have been previously shop-welded and assembled to the rest of the structure on site by using bolted connections.

Advantages used

• A steel structure allows an easy and fast assemblage achieving the shape and geometry of every arch.
• An execution material control would not be required to verify the real strength acquired by the steel. The material guarantees the designed strength by itself.
• A light structure means less repercussion on foundations.
• Most of the structure can be made in large pieces on a workshop, and only the assembly between members will be done on site work.
• Infill material between arches will also be metal deck slab with an 8cm topping layer casted in place with the minimum reinforcements. No formwork is required for this metal slab deck as it is supported on arch-to-arch joists.

Key elements

In order to minimize the disadvantages for the construction of the steel structure, SOCOTEC Spain extended the protection’s time improving the atmospheric corrosion resistance of the structure by oversizing the steel elements.

The structure is thermally protected (i.e.,it is not exposed to large temperature changes) because it also has topcoats projected Vermiculite as fire protection (also makes thermal mattress). We also used an Iterchart supplier to ensure that with a suitable paint thickness, it is possible to achieve 15-20 years of protection.