LocationDe Oversteek, Nijmegen, The Netherlands
Architect in ChargeChris Poulissen
CollaboratorLaurent Ney Engineer
ContractorsBAM, Max Bögl
Budget141.000.000 euro exc VAT
From the architect. The city of Nijmegen formulated the specification of the bridge in a document outlining their ambitions. Within this, design criteria were laid down which helped to set out the project.
A first issue concerns the placement within the surroundings. The urban bridge has to form an integral part of the riverscape, and be both seen and experienced from the banks as well as from the bridge itself. A second criterion requires the design to be consistent with the existing and future image of Nijmegen in terms of the relocation of the dyke and the spatial developments around the Waal River.
This means that the main construction has to stand in relationship to the whole programme and function in an ideal way as a major piece of traffic infrastructure. A third ambition describes the bridge as a work of art that, in a single gesture, articulates contemporary technology and design. The fourth criterion focuses on the function and experiential value of the bridge: the urban bridge should create an ‘urban plaza’, both on deck and at ground level, as well as a pleasant environment underneath.
The design provides more than one answer to all of these questions. The roots of our design culture are reflected in the physical laws of stability and in construction craftmanship, but also in the landscape, the topographical conditions, the city and its history: the traditions and the culture of a place form a starting point. Our design approach starts from ‘the nature of things’. We utilise the valuable elements that can be found within the very broad context of the project.
In addition, the economics and the organisation of financial processes, decision-making procedures and regulations, operate according to their own logic and systems: today, this needs to be planned and incorporated into complex construction projects. This is what we understand by the integral approach. By proceeding in this way, we are confident that our projects generate unpredictable added value, differentiate themselves from the existing surroundings and, on top of that, set other transformations in motion.
An integral approach also means that all the parties involved, from various disciplines and functions, rise to the challenge. There is permanent communication: this is non-hierarchical and based on the belief that this is essential when dealing with modern day complexities.
Design of the bridge
The design of the bridge is a staging. It is a theatrical response to the majestic nature of the Waal River, the floodplain and the two embankments. The urban bridge brings structure, hierarchy and orientation to the landscape. The arch, which is the main feature, both confirms and spans the river. Unlike a purely functional span across the water, the arch respects the width of the river and thus endorses the location of its banks. Even in winter, when the water levels are higher and the floodplain overruns, the arch remains convincing proof of the location and identity of the Waal.
The design of the bridge is based on a structural logic that takes, as its starting point, the principle that the geometry is determined by the forces at work. We do not choose forms for their own sake, but use the forces to develop a shape. The forces thus become a design tool. Once the basic geometry can be fixed, the ‘composition’ or materialization of this form can be investigated. The need for a new bridge provided the opportunity to create a 21st century arch bridge, a contemporary icon of Western culture. The Waal Bridge as a counterpart and ‘monument of its time’ raises expectations even higher in terms of formal and engineering ambitions.
The ramps of ‘De Oversteek’ are designed from a range of materials and construction methods that relate to nature. It involves traditional techniques (cast in situ concrete and brick masonry) that create a feeling of craftsmanship. The design, materials, dimensions and detailing of the ramps, unlike the arch bridge, are elaborated on a human scale. The new bridge is designed with an integral approach, using a combination of contemporary knowledge on master planning, construction techniques and conceptual design.
The bridge is the result of a well thought-out process of optimisation combining engineering with urbanism and architecture. A principle aim of the design process is to make the structural efficiency visible. There are no added ‘counterfeits’. The bridge is coherent and logical in relation to physical laws. Natural beauty is a consequence. The main span of the arch bridge is 285m long; the total length of the structure, the arched bridge including the approach ramps, is 1,2 km.