Built on a mountainside at Jrabta in Lebanon, this imposing structure is designed to give the impression of a ship - its roof appearing to form a continuation of the surrounding hillside.
The challenging design of the roof, as a one-way slab resting on concave beams, included spans which averaged around 32m and a concave shape with variable sectional geometry. As a consequence, the weight of the beams would have proved to be problematic and would have yielded large flexural effects.
The CCL design team responded to these challenges with a series of innovative solutions. Voided sections allowed the reduction of beam self-weight while providing efficient inertia. Pot bearings were used at beam-column joints to act as a pinned connection without transferring any moment to the column, while temporary sliding bearings let the beams displace under post-tensioning, shrinkage and self-weight deformation. The locking of the bearing for the final stage secured the beams laterally.
The PT tendons were stressed prior to casting the slab, in order to maximise pre-compression in the beam, the sequencing of the post-tensioning within the beam itself. The other other beams helped to introduce the post-tensioning in a gradual manner. Displacement monitoring was carried out to allow validation of design equations in the case of complex slab geometry.