Detailed formwork planning pays off

Construction of the new Rhein-Galerie in Ludwigshafen: A challenging complex of circles, ellipses and spirals

The fabric of the Rhein-Galerie in Ludwigshafen is currently one of Hünnebeck GmbH’s biggest and most sophisticated formwork projects in Germany. The appeal of the mega project (106,000 m² of gross floor space) lies in the circular and elliptical building structures, and it is here that general contractor Züblin has opted for a combination of precast elements and cast-in-situ concrete. The delivery of all the formwork solutions, including the custom forms, has been entrusted to the Hünnebeck branch in Riedlingen. The entire processing of the formwork project is in the hands of the project developers in Ratingen.

The new shopping mall (for client ECE Projektmanagement, Hamburg) along the Rhine promenade and comprising about 120 shops and restaurants on roughly 30,000 m² of retail space is due to open in 2010. The gigantic construction site right by the Rhine is still currently dominated, however, by twelve tower cranes. The 400 m long and 80 m wide building complex under construction consists of the two retail floors on the 1st and 2nd levels (story heights 5.24 and 5.68 m). On the almost 3 m high 3rd level and on the smaller open 4th level are about 1,300 parking stalls which are accessed via two, in each case double-flighted spiral ramps (outer diameter 22 m, inner diameter 10.8 m). The various levels are reached via 14 rectangular building cores of staircases and lift shafts. The approach to the spiral ramps consists of an access tunnel in the form of a trough structure which, at the transition from the tunnel to the spiral ramp, has a threefold twisted slab. The in most cases curved, up to 9 m high walls of the new shopping mall form a total of ten elliptical building units with radiuses of 11.2 to 17.55 m. Among these are two compressed and two overlapping ellipses (peanut-shaped).

So much for the geometry. Overall, more than 82,000 m² of surfaces have to be shuttered, the lion’s share of which, almost 47,000 m², consists of walls. The cast-in-situ joists, suspender beams and parapets add up to 7,100 m². The cast-in-situ slab surface comes to roughly 13,000 m², while a good 15,000 m² of slab surface consists of partially precast slabs, the support for which is also being designed and supplied by Hünnebeck.
When the contractor Züblin (Stuttgart office) in the shape of formwork specialist Thomas Lampeitl (job scheduling) embarked on his search for an efficient formwork supplier, one thing was uppermost in his mind. The supplier should not only handle all the detailed planning of all the formwork solutions, but also supply them punctually to the site. The package required by Züblin also included the production of specially produced custom formwork solutions along with the erection of ready-to-use formwork equipment on site. It was Hünnebeck that filled the bill.

Leading role for Ronda circular formwork
Some 300 A0 plans have been prepared by the formwork supplier’s technical department over the last few months in close consultation with the Züblin formwork planners so that there would be no problems shuttering the geometrically highly sophisticated building structures of the Rhein-Galerie. The leading role in this is being played by Ronda circular formwork, with 1,170 m² of it being available on site. This easy-to-handle formwork consists essentially of heavy-duty, ready-to-use elements that can be adjusted with millimeter precision to any desired radius (upward of 2.75 m) with the inbuilt spindle system.

During the construction of the new mall, the walls of the parking garage ramps and of the circular and elliptical structures will be poured with Ronda formwork. With 3 m tall elements, to be precise, which are mounted on climbing brackets or – a suitably large radius permitting – on folding scaffolds and which, on the parking garage ramps for instance, climb to a height of about 21 m in 7 lifts.

Inclusive of custom forms
Züblin foreman Norbert Pinske, who is responsible for the punctual completion of the complex garage ramps, is highly satisfied with the formwork solutions developed by Hünnebeck: “The design engineers have truly considered every detail and also had all the required custom items built. All we have to do on site is set everything up according to the plan.” For instance, Hünnebeck’s own fabricators constructed the curved and also oblique-angled boxes for the windows in the ramp walls and organized their assembly on site as well.

Custom elements are also necessary, for example, for the construction of the threefold twisted slab at the transition between the access tunnel and garage ramp. To create the complicated pitch of the slab, standard elements of Variomax wooden beam formwork are being combined with tailor-made ribs and bulkheads. A challenging task, for every rib is a one-off and has had to be designed separately.

Elaborate curves
The walls of the total of ten ellipses, which are being shuttered under the watchful eye of senior foreman Wolfgang Kohnle, also make severe demands of formwork design. For instance, the two overlapping ellipses start on angled slabs whose pitch has to be compensated for by special substructures so that the bottom elements of the 3 m tall Ronda forms can be erected. Vertical progress is then made in up to three climbs on climbing brackets or folding scaffolds. The rising curved walls have to be stiffened right down to the base slab and made safe with scaffolds and work platforms on all levels.

Some ellipse radii, however, are so small that they cannot be created with Ronda formwork. In such cases, the custom formwork fabricators spring into action and produce the required formwork elements with absolute precision. The same applies to a number of cast-in-situ parapet sections which are prefabricated with H20 large-area elements and supplied ready-for-use to the site.

Compared to the complex curves, the shuttering of the 14 rectangular building cores with their stiffening function is relatively straightforward. These are poured in the classical manner with Manto large-frame formwork (3,000 m² kept on site). Equally simple, though extremely demanding in terms of quantities for the huge surfaces, is the pouring of the slabs and joists with Variomax wooden beam formwork on ID15 towers (6,000 m² on site) and the support for the precast slabs with H20 yokes (3,000 m).

Good planning makes the difference
Because everyone involved has been working closely together right from the planning stage, the technically extremely challenging project is proceeding smoothly. Although a mere 12 months have been allocated for the fabric, project manager Alexander Vobis is extremely confident: “We’re all pulling together. And because coherent formwork solutions were developed well in advance, everything’s running to a tee.”
Bildunterschriften:

Motiv 4915
The Rhein-Galerie in Ludwigshafen is a mega project that's demanding in terms of the required formwork. Most of the varied ellipses are being poured with adjustable Ronda circular formwork.


Motiv 4948
Hünnebeck has supplied all the required ready-to-use formwork solutions to the site – even the oblique-angled and at the same time curved boxes for the windows in the double-flighted parking garage ramps.


Motiv 4960
Edge protection with the Protecto system, Manto large-frame formwork for everything with corners (left in the picture), support systems for the cast-in-situ and partially precast slabs, loads from the rising mall walls discharged down to the base slab with ID15 towers and tubular steel props – almost the entire Hünnebeck product range is in action on the Rhein-Galerie construction site.

Download: PM_Rhein-Galerie_en.rtf

Christian Henkel
Marketing/PR Hünnebeck GmbH
chenkel@harsco.com

back