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Sumit Singhal
Sumit Singhal loves modern architecture. He comes from a family of builders who have built more than 20 projects in the last ten years near Delhi in India. He has recently started writing about the architectural projects that catch his imagination. On the Loing Overpass in France by DVVD ArchitectesJune 21st, 2016 by Sumit Singhal
Article source: Kyubes Agency Designed by the DVVD architecture, design and engineering agency, the overpass on the Loing links the municipalities of Saint-Mammès and Veneux-les-Sablons, in the department of Seine-et-Marne. More than just a connecting structure, this is a sculptural work which banks upon simplicity and elegance in design to enhance an equally remarkable site.  Image Courtesy © DVVD
 Image Courtesy © DVVD At the confluence of the Loing and the Seine, the overpass constructed by the DVVD architecture, design and engineering agency blends perfectly with its remarkable setting in the heart of Seine-et-Marne, a favourite site for walkers in the Ile-de-France. This panorama inspired numerous studies, sketches and paintings by the famous impressionist artist Alfred Sisley in the late 19th century. !00 years later, the spirit of creativity is still at large here, as evinced by the cleancut metal arch, 67 metres in length, which connects the municipalities of Saint-Mammès and Veneux-les-Sablons. First conceived early in the 20th century, the installation of an overpass has been much discussed since, with a fear in many quarters of the consequent spoiling of the site. It was by the particular consideration of this mandatory respect for the existing setting that the DVVD agency was able to win the competition organized in 2010 by the Inter-municipal Syndicate of Boundary Developers [Syndicat Intercommunal des Maisons du Bornage]. Given a free choice of location, the architects sited their project at the margins of the Seine, at a location where the Loing is relatively broad, and where the banks are free of road traffic and urban development. This siting also allows the lines of force delivered by the landscape to be exploited, and to enjoy the fruits of reciprocal enhancement.  Image Courtesy © DVVD  Image Courtesy © DVVD Caressing both banks, the overpass unfurls freely, on the left bank towards the Veneux-les-Sablons tow path, and on the right bank towards the car park of the Saint-Mammès market. Its arched form is more clearly suggestive of a water crossing than a girder or trellis structure, while establishing a strong visual link between the two towns. The structure is supported on foundations which are independent of the banks, which themselves are reinforced over a length of 10 – 15 metres: on the Saint-Mammès side, the existing quayside, of cement construction but affected by cracks, has been consolidated by the installation of a beam; on the Veneux-les-Sablons side, a bundled structure of willows and timber piles, combined with geotextiles, improves the mechanical strength of the bank, hitherto comprised of backfill covered with herbaceous vegetation and a few woody plants. The symmetrical design of this structure is comprised of two slender load-bearing arches, with a deck suspended from reinforcements which are supported by the arches. Manufactured and painted at the Viry workshops in Remiremont (Vosges), the latter were transported in three sections respectively and welded in situ. The curvature in elevation is matched by the curvature of the decking plane: the decking is expanded in the central section to form a panoramic viewpoint over the river. Over and above its function as a crossing, the overpass serves as a landmark, a destination for walkers and an exceptional observation point.  Image Courtesy © DVVD  Image Courtesy © DVVD The overpass is distinguished by the restraint and elegance of its geometry, which render it virtually transparent in the landscape, without impairing the impression of freedom and exposure to the sky which are symbolic of the confluence of the Loing and the Seine. This sensation is attributable to the lightweight profile of its superstructure, constructed of high performance steel, for the optimization of structural behaviour. The arches are designed in rectangular sections, reconstituted by welding, constant in the area above the decking and of variable inertia in the lower sections, flaring to form a bedding structure at ground level. The reinforcements which support the decking are also reconstituted by welding in a variable inertia arrangement, and are suspended from the arches. The overall form of the structure is resistant to bending, but also to torsional loading associated with winds or the application of imbalanced dynamic loads to the decking. Dictated by the proximity of the naval shipyard, the air draft has been extended up to 6 metres, reducing the visual impact of the structure while enhancing the dynamism of its design. Broadly-spaced cradles (at intervals of 5.40 metres) are suspended below the arches, and carry H-section girders for the formation of the decking structure. In the interests of convenience, natural water drainage and anti-slip properties, the latter is formed of rot-proof timber planks in a crosswise arrangement. The architects from DVVD summarize the design as follows : “ In spirit, the project as a whole is distinguished by details, which we have endeavoured to keep clean and simple, allowing the intent of the project to take precedence ”.  Image Courtesy © DVVD  Image Courtesy © DVVD Constraints associated with the observation of the river transport loading gauge, and associated with accessibility for environment-friendly forms of transport and persons with reduced mobility, have resulted in the deployment of appropriate systems. In order to avoid blocking the view to the river, and to prevent the loss of parking spaces, the option of ramps has been excluded. The least cumbersome access solutions possible have been preferred: two stairways, in compliance with PRM standards, supplemented by two smooth and inclined platforms for the upward access of pushchairs, and a rail to facilitate the climbing and descent of bikes. In preference to the deployment of lifts, and their resulting encumbrance on the landscape, monolifts are arranged along the discrete safety rails on each bank, with reinforcements for the installation of two guide rails. The stairways are provided with a similar finish to the decking, with 195 x 35 planks at 40-millimetre intervals, of sufficient width to be secured at four to six points, and longitudinally grooved. The anti-slip facility is enhanced by the incorporation in each plank of two machined recesses, filled with a mixture of silica sand and resin of the corundum type. In the interests of safety and comfort during crossing, the decking is lit from the safety rails, with the addition of projectors to illuminate the arches from the base of the structure. All hardware has been selected with characteristics which will permit operation in a punishing urban environment, with limited maintenance requirements.  Image Courtesy © DVVD  Image Courtesy © DVVD Given the importance of this structure, and its location, highly stringent regulatory conditions have been applied. An initial detailed analysis of hydraulic impacts (with the modelling of water run-off at the confluence, under normal circumstances but also under high-water conditions), revealed a very low, if not zero impact upon water run-off, associated with the limited footprint and the slender design of this structure. An evaluation of impacts upon the natural environment was also completed and referred to the River Police who, after the conduct of an analysis, approved the execution of the project. As this is a classified site, a number of meetings with the architectural heritage agency ABF (“Architectes des Bâtiments de France”) and with the DRIEE (Regional and Inter-departmental Directorate for the Environment and Energy) were also necessary for the optimum appraisal of impact upon the landscape, and for the finalization of the moss grey colour of the metal components. In complete harmony with the landscape, the DVVD agency has delivered a work which is remarkable in every respect: elegant lines, lightweight construction, simplicity, accessibility and low impact. With these qualities, the overpass creates a sense of always having belonged to its surroundings. This project convinces by the strength of evidence.  Image Courtesy © D.Rousselot  Image Courtesy © D.Rousselot DVVD is a Paris based group of architects, engineers, designers, builders and thinkers effective within the fields of architecture, urbanism, research and development. The office gathers over forty people, involved in a large number of projects throughout Europe. To deal with today and tomorrow challenges in urban design and architecture, we explore new fields by overlapping conventional approaches, taking advantage of our solid know-how, with new concept to better fit the future life forms. Finally, we create unique, lively, sustainable projects that reach beyond themselves and become a durable value to the users, the society and the culture they are built into.  Image Courtesy © DVVD  Image Courtesy © DVVD  Image Courtesy © DVVD  Image Courtesy © DVVD  Image Courtesy © DVVD  Image Courtesy © DVVD
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Tags: France, Moret-sur-Loing Category: Bridge |
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