The design developed for the retain

The design developed for the retaining wall was driven by the concept of clamping the foundation in the rock, while preventing the slippage of the rock layers. To prevent slippage and carry the enormous forces from the slope weight, a foundation structure with a large moment of inertia was realised. Fourteen very large barrette foundations were arranged as single elements, with their longest plan dimension parallel to each other at intervals of 7·15 m. The barrettes were placed with the direction of their largest horizontal inertia moment parallel to the slope (see also Fig. 2(b)). Inside each steel cage, six pre-stressed steel cables are positioned (see Fig. 3(b)). The pre-stressed cables have two main tasks: (a) reducing the wall bending and deformation (including concrete creep); (b) ensuring high enough tensile strength of the barrettes