B R E I F B A C K G R O U N DDelhi, the capital of India faces the issues and problems that every developing nation’s city faces - migration, slums, price rise, unemployment and over that a neglected river ‘Yamuna’. This project attempts to tackle all these issues at once in scheme that spans 21 km over the river Yamuna's entire length in city. The idea is that to clean a river that is being polluted at every point inside the city a continuous cleaning mechanism is required that cleans the river all along its entire length. Hence the ‘tube-city’ idea arises - a structure that runs over the river, cleans the river, and further is a small city in itself proving food, shelter, employment and transport facilities without utilizing any more city land. The structure holds farms, residential zones, offices, commercial complexes and transport hub, catering to the current problems of city.V E R T I C A L Z O N I N GThe complete length of the structure is divided into multiple functionary zones based on the surrounding area’s work pattern.Beginning from the outskirts of the city, here the major function remains farming and agriculture based. The commercial complex comprises of large wholesale markets that deal in buying and selling of the food crops grown inside and around the structure.As the structure moves into the core of the city the focus of the structure changes from agriculture to housing and open spaces. The top level changes its function from farms to vast open public parks. Since the area surrounding the structure lack in open grounds the structure acts as a breather space to the area.Moving into the core of the city, the ‘ITO’ complex, the structure now focuses only offices and commercial complexes. Thus changing its functionality with respect to the area it passes through inside the city, and integrating itself into the city fabric.A similar pattern is followed by the structure on its way out of the city towards the southern side. H O R I Z O N T A L Z O N I N GSimilar to the vertical splitting the cross-section of the ‘tube-city’ consists of layered functions. FARMS / OPEN GREENSStarting from the top is the open parks / farming plains which remain a constant function of structure throughout its cross-section. The vast farming area supprorts the food reqirement of the settlements inside the structure and of the city. Towards the interior of the city the farms change into open playgrounds, gardens and parks, which is the requirement of the neigbouring areas as they lack in open spaces for children and the aged.COMMERCIAL COMPLEXIn the middle of the farming plate runs a vertical slit providing light and ventillation to the commercial complex in the middle. This complex also runs along the whole cross-section with shops and markets on both sides.METRO TRANSITBelow the commercial complex is a vast metro transit station complex with 12 platforms. The metro train service runs all along the length of the structure and serves as a major mode of transportation inside the strcuture.RESIDENTIAL ZONEBelow the farming level and towards the periphery are the large residential zones. These are vast areas which are delibrately kept towards the egdes so that they get ample sunlight and ventillation.VEHICULAR LEVELThe level below reisdential zone is a dedicated motorvehicle level, consisting of 16 lane highway. SERVICES / OFFICESThe lower levels are dedicated office zones and service area for the building. Here in the bottom four levels water is purified for reuse inside the building. This water is absorbed from the river below via ‘capillary’ action hence no energy is required to pump the water up to the structure for further distribution and irrigation.S T R U C T U R A L D E S I G NGRIDThe structure is 21 kilometers long and is divided into 4 components : - Primary orthogonal frame- Secondary pyramid frames- Photovoltaic panels- Inner slabsSURFACEThe pyramid shaped protusions on the surface are translucent photovoltaic panels which trap solar energy while allowing more light to penentrate into interior spaces. The building derives its energy from the solar energy falling on the surface.PYLON GRIDThe supporting pylons serve a secondary purpose besides supporting the structure above water, they also carry water from the river to reservoir of the structure via the ‘capillary action’. Through this simple principle water can be transported inside the frame of the structure and can be punctured out for use wherever needed.S Y M B I O T I C R E L A T I O N S H I PThe whole structure works as a self sustainable organism that only utilizes river water while benefitting the river as well as the region around the whole 21 km stretch. It also gives more employment opportunities as well as residential and office space to a city that is suffering from the issue of migration and space crunch. The farming land provides more employment and food for the city as well as for the structure. The mass transit system of roads and metro rail form the soul of the structure, keeping the whole 21km long mass reachable from end to end. The purpose of keeping the structure all along the stetch of the river is to keep the cleaning process of the river active all the time while its inside the city.THE OUTPUTFrom the amalgamation of all the above ideas and processes the building turns out to be a life support system for a city that is suffering from the issues of migration, slums, population, unemployment, energy crisis, food shortage and high price, river pollution and traffic conjestion.