Equilateral Pointed Vault
This equilateral pointed vault has been built above the present office of the Auroville Earth Institute and it is the living room of the house of Satprem Maïni, director of the Auroville Earth Institute. It has the shape of the typical naves used in the European Gothic cathedrals. But these types of naves were built on ribbed arches and were buttressed by flying buttresses. The construction of this vault was an attempt to build the same shape as the gothic vaults but as a barrel vault, without formwork and without flying buttresses. This had been possible with the optimisation method developed by the Auroville Earth Institute.
 Equilateral pointed vault, built free spanning with horizontal courses, House of Satprem Maïni  Varying thicknesses for the bottom to the top: 34 cm at the base up to 7 cm at the apex |
The vault does not require any flying buttresses because its stability is insured by the varying thickness for the bottom to the top and with a well studied keystone. The vault starts at the bottom with 34 cm thickness and it ends on top with 7 cm thickness. The weight of the keystone is essential for the stability of such a vault. A difference of a few kilograms per meter long can cause deformation and ultimately collapse of the structure. It has been built in 36 days with 4 masons and it presents these features: • All courses are entirely laid horizontally with the free spanning. • 3.6 m span, 3.12 m rise, 8 m long • 34 to 7 cm thick • The vault ends with a half cloister dome. • The vault has 2 catenary lunettes of 1.2 m span and 7 cm thick. |
Starting the horizontal courses with the window frame as a template and 2 pipes bent for the cloiste
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Building around the ferrocement ring as a window
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Building horizontally the courses
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Starting the catenary lunette
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Building the catenary lunette with corbelled horizontal courses
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Horizontal courses built by steps
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Horizontal courses laid radials to the arch shape
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Corbelling courses of the catenary lunette
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Bond pattern of the catenary lunette
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Laying the keystone of the lunette
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Completed lunette in 3 days
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Completed lunette from inside
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Stability limit with the horizontal courses
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Building the half cloister dome with stepped horizontal courses
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Vault built free spanning towards the half cloister dome
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Pipes of the half cloister dome as templates
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Preparing the courses for the keystones
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Laying the key stone (lozenge piece and slab)
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First keystones and stepped courses for the cloister dome
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Laying keystones
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Back side with the catenary lunette and the half cloister dome
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Laying keystones in progress
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Vault being built free spanning
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Laying the last keystones
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Raw construction completed in 37 days with 4 masons
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Completed vault from outside
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Varying thickness from 3 cm at the bottom to 7 cm at the top
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Completed vault from outside
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Completed vault, above the office of the Auroville Earth Institute
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Completed vault from inside towards the kitchen and the bathroom
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Completed vault from inside towards the kitchen and the bathroom
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Lunette of the living room
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Lunette from outside
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View on the living room
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