Tailor-made formwork solution for tunnel portal collar
The external walls of the tunnel entrance merge smoothly into the elliptical-shaped portal collar, which continually changes in the radius of the curve and the inclination. RUNDFLEX panels, adjusted to the radius with conical filler timbers and connected with BFD alignment couplers, formed the wall exactly to the curves and provided the shape in the best surface quality. To increase the efficiency of the formwork used, the PERI specialists stacked 2.40 and 1.20 m high panels on top of each other. These units could then be used again for the southern portal, with its altered shape.
An inclined level of 30° formed the platform for the collar formwork. The falsework for this was of MULTIPROP towers and HD 200 heavy-duty props.
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