Contents:

• Introduction• Design Evolution• Components of the structure•Analysis & Design of structural components• Reinforcement• Foundations• Construction challenges • Concreting• Cladding• Conclusion

Introduction:

• Baha’i Faith• A temple in the capital city of India• Architect Mr. Fariborz Sahba was selected by the world governing body of Baha’i faith, “ The Universal House of Justice” in the year 1974• Flint & Neill partnership of London was the consultancy• ECC construction group of Larsen & Toubro Ltd. were the contractors• Design process for the structure began in the year 1976

Design Evolution:

• Architect’s travel throughout India for Proper design• Symmetric Half-open Lotus flower surrounded by its leaves

Model of the Lotus temple

Components of the structure:

• Main building consisting ofBasementThree groups of Nine shells springing from the podiumDouble layered Interior domeNine archesNine pondsWalkways

• Ancillary building consisting of Information centerLibraryAdministrative buildingRest rooms

Analysis & Design of Structural components:

• Spherical surfaces for the Entrance & Outer leaves• Arch soffits have a Parabolic cone shape• Spheres, cylinders, toroids & cones for Inner leaves • Nine intersecting spheres form interior dome• Final geometrically converted shapes were so complex that it took the designers over two & a half years to complete the detailed drawings of the temple.• In-situ Reinforced Concrete construction• Guniting

Analysis & Design of Structural components:

• Interior dome is 28 m in height and 34m in diameter• Inner leaves are of 200 mm thick and of 33.6 m in height• Outer leaves are of 135 mm from their cusps to the line of glazing, beyond which they thicken to 250 mm and of 22.5 m in height• Entrance leaves are of 150 mm at center to 300 mm thick at their edges and of 7.8 m in height• Shells within the interior dome: 60mm thick

Analysis & Design of Structural components:

• Tubular steel glazing frames• Designed for

1.Dead load2.Live load3.Wind load ( Return period: 500 years)Wind tunnel test in Aeronautical Engineering Department at Imperial College, London. 4. Earthquake load

• Finite Element Analysis• Equivalent grillage models for shells in the computer program• Quadrilateral elements

Reinforcement:

• Cold twisted deformed high-tensile steel bars• Galvanized to provide additional corrosion resistance• Hot-dipped the bars prior to bending, having preheated them to 100º C to drive off moisture, Prebent bars tended to suffer cracking during galvanizing. • Tests showed that the mechanical properties of the bars were not significantly affected by the process.

Foundations:

• Heavily fissured quartzite

• Random lenses of mica

• Uncertainties in the positions and extent of the large soft pockets precluded the use of piles and all column foundations were designed as mass concrete pads.

• Neoprene pads were thought of providing to reduce earthquake forces and accommodate thermal movements but in view of intended longevity of the building foundations were placed directly on the rock and designed for full seismic forces and moments.

Construction Challenges:

• Excavations were undertaken by Ahlwalia Construction Company• Primary supports to the formwork for the shells, dome and arches, were designed by the contractor and constructed of welded steel.• Plywood forms• Purlins• Forms and their supports for all shells were designed to withstand pressures from continuous concreting and the outer forms were placed as concreting proceeded.• Three inner leaves were concreted at a time, generally in only two lifts.

Concreting:

• White concrete was decided to be used consisting of white cementsilica sanddolomite aggregate in the proportions: 1:1.5:3.5 by weightplasticizerwater/cement ratio: 0.43

• Slump achieved was in the range of 70-100 mm• Bush hammered finish for the interior dome, inner & outer leaves• Specified strength was M30• Concrete was drum mixed on site

Concreting:

• Three inner leaves at 120º spacing, were concreted at a time, in only two lifts from their bases to the level of the star beams above• Outer & Entrance leaves were concreted in a continuous operation one at a time, using the removable outer shutter panels for access for concrete and vibrators to avoid cold joints.• Concreting time for an outer leaf was of the order of 48 hours.• Ice melt water was used in the mix to take care of the hot weather in Delhi to cool the concrete, that brought down temperature of concrete from 40º C to 25º C.•Systems of horizontal sprinkler pipes were used in curing.

Cladding:

• Shells & arches are clad in white Greek marble panels, preformed in Italy to the surface profiles and to patterns related to the geometry by Marmi Vicentini S.P.A Company.• The panels are fixed by means of stainless steel brackets secured by bolts in holes drilled after concreting and the joints were filled with molded rubber cordon & silicon sealant was applied over it.• Floor finishes were also of white marble• Balustrades, stairs were precast• Stones used for stairs were made of red sandstone.• Complete construction of the structure was completed in the year 1986.

Conclusion:

• The Baha’i temple is probably one of the most special and most distinctive buildings to be built in today’s world• The structure’s complexity and the high standard of quality demanded of the workers meant that supervision of construction had to be very dynamic and endowed with an acute capacity to immediately perceive innovatory processes.• Necessary too was a group of technical personnel and of workmen who were conscious of the task they were performing and imbued with an authentic spirit of cooperation.• The completed structure remains both Architecturally and in Engineering

point of view , as a MARVEL!

Presented by: P. Chandrasekhar B.E.Civil (4/4) University College of Engineering Osmania University