The Southern Ring Road of Groningen is not new, it has been in use for decades. Now it is up for a total make over. Much wider than its predecessor, with increased capacity. Significant tracts of the road will be built underground, reducing noise and pollution in the surrounding city. The new Southern Ring will no longer be a road that cuts through the city, but a part of the city where the road is a guest. The cross section below shows how the road finds its way through Groningen, sometimes above, sometimes under the ground. The four main design challenges are visible at a glance: the design of the structural works, the green node Julianaplein, the recessed road with a park above and last but not least: keeping Winschoterdiep open. In this way we can save the 400 year old canal towards the rest of the Netherlands.
Construction Combination Herepoort (a collaboration of the German contractors Max Bögl and Zueblin and the Northern Road Building Combination) has commisioned our office and wUrck for the design of the project. On all aspects of landscape, urbanism and architecture. Between May 2015 and March 2016, we have worked with wUrck and the tender team of Herepoort on the translation of the Aesthetic Program of Requirements into a comprehensive tender design. The competition has been won by us and is being developed into a buildable plan. In this large and complex project our focus is on the design of the various structural works and the green node Julianaplein.
The design of the structural works
The Aesthetic Program states there are two types of structures: “urban structural works” and “underpasses”. Urban structural works are viaducts over or under water and roads, facing the city. Urban structural works should be finished with typical Groningen style brick architecture. The underpasses in contrast are enveloped in green and are practically invisible from the surrounding city. The picture below is a zoom in on two of the major hubs in the Ring Road (Vrijheidsplein and Julianaplein). Both types of structural works are present here. At the urban structural works it is immediately apparent there are several types: large and small, straight and curved, all new construction or expansion of existing viaducts. We have designed a smart tool kit fitting any type of structural work and linking the economic power of prefabrication to a beautiful, almost artisanal look.
The smart tool kit
The tool kit consists of elements of concrete, brick and noise barrier. The tool kit is constituted in such a way that the approximately 15 types of different urban structural works can all be built in a high-quality and economical way, in straight and in curved form. We have made a special brick for this work, which is only a few centimeters thick, but with a large surface area and large bed joints. As a result, the relatively expensive material brick is restricted to a minimum. We propose to use vertical masonry with mortar joints so that curved surfaces can be made in a simple and cheap way, but also with fine curves. The wide bed joints offer hiding places for mice and spiders, in the long run also plants.
Between concept and buildable plan lies a complex process where collaboration but also the latest technology is the key. Syb van Breda & Co tackles this with parametric design. By creating a script changes can easily be made through adjusting the input. 2D drawings are automatically generated from a 3D model, saving time in the design process. In this way the structural works are drawn in detail.
Both types of urban structural works can be found on the Vrijheidsplein: the big structural work in the center already exists, but is widened with a new lane and a brick facade on either side. The adjoining access viaducts are completely new structural works. Underneath the node goes a “left turn”, which is sunk into the ground. This structural work does not face the city and therefore has no masonry finish.
As with the structural works, there are also several types of underpasses. The open type (without roof) at Vrijheidsplein and the closed type (with roof), actually a short tunnel, at Julianaplein. These underpasses ensure that most of the road is underground and enveloped in green. In line with the Aesthetic Program of Requirements, we have ensured a minimum of visible concrete.
At this junction A7 and A28 motorways merge. In the current situation, this is an asphalt, traffic lights and concrete jungle in the middle of the city. The new situation, by contrast, is very green, with views to a water landscape and smooth connections without traffic lights. The highway is enveloped in green making it barely visible from the city.
For cyclists and residents
The new Julianaplein is not only for cars on the highway, but it also brings significant improvement for local residents and users of the road network. In the new situation, the local roads are comfortable green and spacious, with good and safe views to the surroundings. Also for cyclists, the situation improves dramatically. Separated cycle paths along the Noord-Willemskanaal and a bicycle valley under the A28 provide safe and fast connections under the highway and slip roads. A large underpass with good viewing angles ensures a safe passage.
We have paid special attention to the situation at Maaslaan. This is where the new Ring Road and parallel roads are built very close to urban areas. Of course there are noise barriers. But we want to go further. In lieu of concrete noise barriers (do you already see the grafitty?) We offer a green “living” sound screen. Noise barriers that are not covered with greenery, but where plants actually grow inside. Water supply systems ensure that the plants remain alive, even in long dry summers.