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CONSTRUCTION OF DOMES

  1. DOMES BY:- SONAL BHARADIA SAMIKSHA CHOUDHARY
  2. INTRODUCTION A DOME IS A THIN CURVED SURFACE OBTAINED BY REVOLUTION OF CURVED SURFACE ABOUT A VERTICAL AXIS. IT IS AN ELEMENT OF ARCHITECTURE THAT RESEMBLES THE HOLLOW UPPER HALF OF A SPHERE. -THE THICKNESS OF DOME IS VERY SMALL AS COMPARED TO ITS OTHER DIMENSIONS -IT VARIES FROM 75MM TO 150MM. -IT IS VERY ECONOMICAL IF THE COST OF SHUTTERING IS REPETITIVE. -THEY ARE SUBJECTED TO COMPRESSIVE STRESSES ONLY. -IT CAN BE CIRCULAR OR CONICAL AND THIS CAN BE OBTAINED BY REVOLUTION OF SEGMENT OF A CIRCLE OR A SLANTING LINEABOVE VERTICAL AXIS. -A FIBRE IN A DOME IS SUBJECTED TO MERIDINAL THRUST AND HOOP STRESS IN THE DIRECTION OF MERIDIANS AND LATITUDES RESPECTIVELY. -AT THE FREE EDGE OF THE DOME,MERIDINAL STRESSES HAVE HORIZONTAL COMPONENT WHICH IS TAKEN CARE BY PROVIDING A RING BEAM WHICH IS SUBJECTED TO HOOP TENSION.
  3. EVOLUTION OF DOMES •THE EARLIEST DOMES WERE LIKELY DOMED HUTS MADE FROM SAPLINGS, REEDS, OR TIMBERS AND COVERED WITH THATCH,TURF OR SKINS. •THE EARLIEST DISCOVERED REMAINS OF DOMED CONSTRUCTIONS MAY BE FOUR SMALL DWELLINGS MADE OF MANMOTH TUSKS AND BONES. THE FIRST WAS FOUND BY A FARMER IN UKRAINE, IN 1965 WHILE HE WAS DIGGING IN HIS CELLAR AND ARCHAEOLOGISTS UNEARTHED THREE MORE. •DURING NEOLITHIC PERIOD IN THE ANCIENT NEAR EAST, SMALL DOMES IN CORBELLED STONE OR BRICK OVER ROUND-PLAN HOUSES WERE SERVED AS DWELLINGS FOR POORER PEOPLE BUT DOMES DID NOT PLAY AN IMPORTANT ROLE IN MONUMENTAL ARCHITECTURE. •ANCIENT STONE CORBELLED DOMES HAVE BEEN FOUND FROM THE MIDDLE EAST TO WESTERN EUROPE. CORBELLED BEEHIVE DOMES WERE USED AS GRANARIES INANCIENT EGYPT, IN MASTABA TOMBS OF THE OLD KINGDOM FROM THE FIRST DYNASTY, AS PRESSURE- RELIEVING DEVICES IN PRIVATE BRICK PYRAMIDS OF THE NEW KINGDOM. CORBEL DOMES - THOLOS OF ATREUS
  4. • THE CONSTRUCTION OF THE FIRST TECHNICALLY ADVANCED TRUE DOMES BEGAN IN THE ROMAN ARCHITECTURAL REVOLUTION TO SHAPE LARGE INTERIOR SPACES OF TEMPLES AND PUBLIC BUILDINGS, SUCH AS THE PANTHEON. •SQUINCHES, THE TECHNIQUE OF MAKING A TRANSITION FROM A SQUARE SHAPED ROOM TO A CIRCULAR DOME, WAS MOST LIKELY INVENTED BY THE ANCIENT PERSIANS. •THE ONION DOME BECAME ANOTHER DISTINCTIVE FEATURE IN THE RUSSIAN ARCHITECTURE, OFTEN IN COMBINATION WITH THE TENTED ROOF. PANTHEON
  5. ANCIENT-ONE OF THE OLDEST TECHNIQUES OF EARTH ARCHITECTURE IS THE BRICK STRATEGY, WHICH WAS OFTEN USED TO CONSTRUCT BRIDGES AND ARCHES. •IN THIS TECHNIQUE, CONCRETE, BRICK OR STONE ARE PUT ON TOP OF A WOODEN FRAME, WHICH IS MOLDED ACCORDING TO THE DESIRED SHAPE. •THE MOLD HELPS IN HOLDING THE STONE OR BRICK IN PLACE UNTIL IT SETTLES AND SUPPORTS THE WHOLE STRUCTURE. MODERN- THE STRESSED SKIN TECHNIQUE IS A MORE MODERN BUILDING METHOD. • THIS USES METAL OR FIBERGLASS PANELS RIVETED TOGETHER. • THE METHOD SAVES COSTS AND DOESN’T REQUIRE ANY BEAMS OR SUPPORT STRUCTURE. HOWEVER, TO PREVENT ANY KIND OF CONDENSATION, IT BECOMES NECESSARY TO INSTALL INSULATORS IN THE STRUCTURE. • THE MONOLITHIC, YET MODERN TYPE OF DOME CONSTRUCTION IS MADE OF THREE PHASES. THIS INVOLVES USING A SPECIAL TYPE OF MEMBRANE THAT IS INFLATED AND PLACED ON THE DOME, GIVING IT A FINISH THAT SERVES LIKE A WEATHER-PROOF SKIN, BUT THAT CAN ALSO BE DAMAGED VERY EASILY. • HOWEVER, THE MATERIALS USED IN THE PROCESS ARE NOT ENVIRONMENTALLY FRIENDLY AS THEY HAVE OIL-BASED CHEMICALS. ANCIENT AND MODERN TECHNIQUES FOR CONSTRUCTION OF DOMES :
  6. HISTORY: ➢ THE CONSTRUCTION OF THE FIRST TECHNICALLY ADVANCED TRUE DOMES BEGAN IN THE ROMAN ARCHITECTURAL REVOLUTION TO SHAPE LARGE INTERIOR SPACES OF TEMPLES AND PUBLIC BUILDINGS, SUCH AS THE PANTHEON. ➢ SQUINCHES AND PENDENTIVES, THE TECHNIQUE OF MAKING A TRANSITION FROM A SQUARE SHAPED ROOM TO A CIRCULAR DOME, WAS MOST LIKELY INVENTED BY THE ANCIENT PERSIANS. ➢ THE ONION DOME BECAME ANOTHER DISTINCTIVE FEATURE IN THE RUSSIAN ARCHITECTURE, OFTEN IN COMBINATION WITH THE TENTED ROOF. ➢ CORBEL DOMES AND TRUE DOMES HAVE BEEN FOUND IN THE ANCIENT MIDDLE EAST IN MODEST BUILDINGS AND TOMBS. PANTHEON TAJCORBEL DOMES - THOLOS OF
  7. TYPES OF DOME : CORBEL DOME: o EARLIEST DOME FORMS o IT IS FORMED BY HORIZONTAL MASONRY CONSTRUCTIONS THAT GRADUALLY DECREASE IN SIZE TO CREATE A SEMI-SPHERICAL SHAPE ONION DOME: o THE ONION DOME IS A BULBOUS DOME THAT WIDENS FROM A SMALL BASE AND THEN TAPERS TOWARD THE TOP, SIMILAR TO THE DOME OF THE TAJ MAHAL DRUM DOME: o COMMON DOME SHAPE o SIMPLE SEMI-SPHERICAL SHAPE THAT EXTENDS UP FROM A CIRCULAR BASE. EG.PANTHEON CORBEL DOME - THOLOS OF ATREUS ONION DOME – TAJ MAHA DRUM DOME-PANTHEON
  8. OVAL DOME: o THE OVAL DOME HAS AN OVAL OR EGG-SHAPED BASE AND EXTENDS UPWARD MUCH LIKE A SPHERICAL DOME. o EG: BAROQUE OR LATE RENAISSANCE BUILDINGS SAUCER DOME: o CIRCULAR BASED DOMES o CREATE A LOW-PITCHED SHAPE THAT LOOKS MORE LIKE AN INVERTED SAUCER THAN A HALF SPHERE. UMBRELLA DOME: o ALSO CALLED AS SCALLOPED DOME. o THE WEIGHT OF THE DOME IS SUPPORTED BY VERTICAL STRUCTURES THAT GO FROM THE BASE TO THE CENTER, DIVIDING THE DOME INTO SEGMENTS. GEODESIC DOME: o A GEODESIC DOME IS A SPHERICAL OR PARTIAL-SPHERICAL SHELL STRUCTURE OR LATTICE SHELL BASED ON A NETWORK OF GREAT CIRCLES (GEODESICS) ON THE SURFACE OF A SPHERE. o THE GEODESICS INTERSECT TO FORM TRIANGULAR ELEMENTS THAT HAVE LOCAL TRIANGULAR RIGIDITY AND ALSO DISTRIBUTE THE STRESS ACROSS THE STRUCTURE. OVAL DOME SAUCER DOME UMBRELLA DOME
  9. FORCES ACTING ON DOMES:- 1)SELF WEIGHT OF THE SURFACE 2)UNIFORMLY DISTRIBUTED LIVE LOAD 3)WIND LOAD 4)LOAD OF THE UPPER EDGE
  10. •DOMES ARE ALSO CHARACTERIZED BY A THRUST. •THE DOME’S THRUST IS COMPOSED OF ITS WEIGHT AND THE HORIZONTAL THRUST OF THE BASIC ARCH SECTION. •EDGE FORCES ARE TANGENTIAL TO THE SURFACE OF THE SHELL AND CAN THEREFORE BE SUPPORTED BY A BUTTRESS (MERIDIONAL FORCES) OR BY RING BEAM. •DOME IS CREATED BY THE ROTATION OF AN ARCH AROUND A VERTICAL AXIS, ANOTHER FORCE IS ACTING IN IT: THE CIRCULAR FORCE (CF) OR HOOP FORCE WHICH ACTS IN LATITUDINAL DIRECTION. UNLIKE AN ARCH, A DOME CAN RESIST OUT-OF-PLANE BENDING BECAUSE OF INTERNAL HOOP FORCES •HOOP FORCES ALLOW RING-BY-RING CONSTRUCTION OF A MASONRY DOME, AN UNFEASIBLE TASK FOR AN ARCH. AS A RESULT, THOUGH AN ARCH IS UNSTABLE WITHOUT ITS KEYSTONE, A DOME WITH AN OCULUS IS PERFECTLY STABLE FORCES ACTING IN DOMES ROUGH PLAN OF RING BEAM RING BEAM REINFORCEMENT
  11. •THE DOME CAN BE ASSIMILATED TO AN INFINITESIMAL NUMBER OF ARCHES WHOSE THRUST RADIATES FROM THE CENTRE TOWARDS THE PERIPHERY. •ON THE SPRINGER LEVEL, THE COMBINATION OF ALL THESE HORIZONTAL THRUSTS WILL CREATE A PERIPHERAL TENSION (PT) WHICH WILL TEND TO OPEN THE WALL SUPPORTING THE DOME. •THE COMBINATION OF THE MULTITUDE OF CIRCULAR FORCES AND LINES OF THRUST WILL CREATE A NET OF COMPRESSION FORCES WHICH WILL DEVELOP ON THE ENTIRE SURFACE OF THE DOME. •THEREFORE, IT CAN RESIST TREMENDOUS STRESS. •IN CASE OF FAILURE OF ANY PART OF THE DOME, UNDER AN EXCEPTIONAL STRESS, THIS NET OF COMPRESSIVE FORCES WILL FIND ANOTHER WAY TO ACT IN THE DOME, AND THE LATTER WILL RARELY COLLAPSE ENTIRELY AS LONG AS THE SUPPORTS (WALLS OR COLUMNS) ARE INTACT. CF = Circular force in every ring LT = Line of thrust of “an arch” of the dome HT = Horizontal thrust of “an arch” of the dome W = Vertical weight of “an arch” and the overload T = Thrust, resultant force of the horizontal thrust and weight of “an arch” P = Peripheral tension which is created by the combination of the horizontal thrusts of all the arches, that are radiating from the centre •THEY CAN BE BUILT EITHER ON CIRCULAR OR QUADRANGULAR PLANS.
  12. STABILITY OF DOMES • THE EXAMPLES OF DOMES BUILT ALL OVER THE WORLD THROUGH THE AGES SHOW THAT DOMES CAN HAVE A WIDER VARIETY OF SHAPES THAN VAULTS. •FOR INSTANCE, A DOME CAN BE CONICAL WITH ANY PROPORTIONS: FROM A SHARP ONE TO A FLATTER ONE. •BUT IT IS OBVIOUS THAT AN ARCH CANNOT HAVE A TRIANGULAR SECTION •THEREFORE, IT APPEARS THAT IF ARCHES OR VAULTS ARE STABLE, DOMES OF THE SAME SECTION WILL NECESSARILY BE STABLE. BUT THE OPPOSITE IS NOT NECESSARILY TRUE, AS WE HAVE SEEN WITH THE CASE OF THE CONICAL DOME AND THE TRIANGULAR ARCH. Conical circular dome Triangular arch •THE MORE THE RISE OF DOME (OR ARCH) AS COMPARED TO THE SPAN, THE MORE STRONGER IT IS. •THEREFORE CATENARY DOMES ARE MORE STABLE AND REQUIRE LESS SUPPORT THAN THE SEGMENTAL DOMES.
  13. •SOMETIMES, WHEN LOADED, THE DOME MAY NOT COINCIDE WITH THE LINE OF PRESSURE. •THEREFORE, AN ADDITIONAL FORCE IS REQUIRED TO RESIST BENDING. •THAT IS TO ADD HOOP COMPRESSION RINGS WHICH PROVIDE THE HORIZONTAL FORCE NEEDED. •WAY TO CREATE A DOME WITHOUT HOOP COMPONENTS IS TO USE RIBS THAT ARE COMPOSED OF TRUSSES, AS IS FOUND IN MANY STEEL DOME SYSTEMS. •WITH THIS DESIGN IT IS USEFUL TO ADD A COMPRESSION RING TOWARDS THE TOP OFTHE DOME TO COUNTER THE INWARD TRUSS TRUSSED DOME WITH COMPRESSION RING LINE OF PRESSURE
  14. DIFFERENT TYPOLOGIES OF DOME
  15. •THE PURPOSE OF THREE-DIMENSIONAL COMPRESSION SYSTEMS IS TO CREATE A LARGE, UNOBSTRUCTED INTERIOR SPACE THAT CAN BE UTILIZED IN A NUMBER OF WAYS. •IT USES COMPRESSIVE FORCES TO TRANSFER THE LOAD FROM THE TOP OF THE DOME DOWN ALONG THE MEMBERS WHICH SUPPORT THE SYSTEM. •SOME COMMON DOME SHAPES ARE: OVERVIEW 1. CONICAL DOME 2. SQUARE DOME 3. ELLIPTICAL DOME 3. ELLIPTICAL DOME IN SECTION WITH THE USE OF A TRUSS SYSTEM TO BEAR THE LOAD. 1. THE CONICAL DOME SHOWS A SERIES OF RIBS THAT TRANSFER THE LOAD DOWN THE STRUCTURE TO THE SUPPORTS BELOW. 2. THE SQUARE DOME RESTS ON TOP OF PENDENTIVES, WHICH CONNECT THE BOTTOM RIM OF THE DOME TO THE ARCHES ON WHICH IT RESTS. TRUSSED RIB (SECTION) PLAN
  16. •REINFORCED CONCRETE COMBINES PROPERTIES OF STEEL AND CONCRETE TO RESIST BOTH TENSION AND COMPRESSION. •ONE OF THE LARGEST REINFORCED CONCRETE DOMES MEASURES 663 FEET (202METERS). •SOME EXAMPLES OF REINFORCED CONCRETE DOMES ARE THE KING DOME IN SEATTLE (DISMANTLED IN 2000) AND THE ALGECIRAS MARKET IN SPAIN. 1. REINFORCED CONCRETE TYPES OF DOMES BASED ON MATERIALS THE KING DOME . THE ALGECIRAS MARKET •ONE OF THE LARGEST CONSTRUCTED STEEL DOMES MEASURES 713 FEET (218 METERS).SOME EXAMPLES OF STEEL DOMES ARE THE ASTRO DOME IN HOUSTON AND THE OSAKADOME IN JAPAN. 2. STEEL •STEELDOMES USE THREE-DIMENSIONAL TRUSSES AND HAVE A LIGHTER CONSTRUCTION THAN CONCRETE DOMES. •STEEL HANDLES COMPRESSION AND TENSION BETTER THAN CONCRETE DOES. •LARGER DOMES USE STEEL BECAUSE IT CAN HAVE A GREATER SPAN MORE EASILY THAN CONCRETE.
  17. 3. WOOD •WOODEN DOMES ARE MADE OF WOOD COMPOSITES COMBINED WITH JOINTS AND STEEL FRAMES. •WOODEN DOMES ARE FAVORED FOR THE WARMTH OF THE WOOD ITSELF, BUT THEY CANNOT SPAN DISTANCES LIKE CONCRETE OR STEEL. •ONE OF THE LARGEST WOODEN DOMES MEASURES 584 FEET (178 METERS). •SOME EXAMPLES OF WOODEN DOMES ARE THE TACOMA DOME IN WASHINGTON AND THE ODATE JUKAI DOME IN JAPAN. 4. MASONRY •MASONRY WAS USED IN EARLY DOME CONSTRUCTION BECAUSE IT WAS WIDELY AVAILABLE. •MASONRY DOMES HAVE THE SMALLEST SPAN OF ALL THE MATERIALS MEASURING, AT LARGEST, 141 FEET (43 METERS). •SOME EXAMPLES OF MASONRY DOMES ARE THE PANTHEON IN ROME AND ST. PAUL’S CATHEDRAL IN LONDON.
  18. NUMERIC PARAMETERS •THE SMALLEST SPANS ARE ACHIEVED BY USING MASONRY BECAUSE THE WEIGHT OF THE MATERIAL IS LARGE AND THE STRENGTH IS LOWER. •STEEL PROVIDES THE LARGEST SPANS BECAUSE LESS MATERIAL IS NEEDED AND THEREFORE THE STRUCTURE ITSELF WEIGHS LESS. ADDITIONALLY STEEL PROVIDES A HIGH MATERIAL STRENGTH. •GEODESIC DOMES HAVE BEEN WIND-TUNNEL TESTED TO WITHSTAND WIND SPEEDS UP TO 200 MPH.
  19. BASIC STEPS INVOLVED IN THE CONSTRUCTION OF DOME:- 2)MARK THE CENTER POINT AND INSERT THE TRAMMEL. 5)BUILD THE SIDES 4)THE PIVOT WILL RISE AS THE DOME RISES. 3)CREATE A PIVOT TO KEEP THE DOME IN LINE. 1)START WITH A FOUNDATION
  20. BRICK MASONRY DETAIL:- -THIS IS HEMISPHERICAL DOME WITH CONSTANT RADIUS WITH THE HELP OF TRAMMEL. DOME MASONRY WORK CONSISTS OF FOLLOWING STEPS:- -FINDING AND FIXING THE CENTER POINT OF THE DOME RADIUS IN RELATION TO THE LEVEL LINE. -LAYER BY LAYER SETTLING OF DOME MASONRY,WITH THE BRICKS SET IN MORTAR POSITIONED AND ALLIGNED WITH THE TRAMMEL AND TAPPED FOR PROPER SEATING. -IN UPPER PART OF THE DOME, WHEN THE TRAMMEL IS STANDING AT STEEPER ANGLE THAN 45 DEGREE,THE BRICKS MUST BE HELD IN PLACE UNTIL EACH COURSE IS COMPLETE. -COURSES ARE INHERENTLY STABLE AND THEREFORE NEED NOT TO BE HELD IN PLACE ANY LONGER.
  21. ENSURE THAT:- - TROWELLING IS DONE VIGROUSLY( TO INSURE COMPACT RENDERING) - ALL EDGES AND CORNERS ARE ROUNDED OFF - THE RENDERING IS ALLOWED TO SET/DRY SLOWLY (KEEP SHADED AND MOIST,AS NECESSARY) - THE MATERIAL COMPOSITION IS SUITABLE AND MUTUALLY COMPATIBLE.
  22. RING BEAM HOOPS MERIDIAN RCC DOME DETAIL :- -MERIDIONAL THRUST ACTING VERTICALLY AND HOOP STRESS ACTING HORIZONTALLY -TYPICAL SPAN= 250’-650’ -CONCRETE IS THICK NEAR THE EDGE OF THE RING BEAM AND TAPERS AS IT GOES UPWARDS. RING BEAM HOOPS MERIDIAN
  23. STEPS FOR CONSTRUCTION OF MONOLITHIC DOME:- MATERIALS REQUIRED:- 1)STEEL-REINFORCED CONCRETE 2)POLYURETHANE FOAM INSULATION 3)INFLATABLE AIRFORM STEPS:- 1=DOME STARTS AS A CONCRETE RING FOUNDATION,REINFORCED WITH STEEL REBAR.VERTICAL STEEL BARS EMBEDDED IN THE RING LATER ATTACHED TO THE STEEL REINFORCING OF THE DOME ITSELF. 2=AN AIRFORM,FABRICATED TO THE PROPER SHAPE AND SIZE IS PLACED ON THE RING BASE. USING BLOWER FANS, IT IS INFLATED AND THE AIRFORM CREATES THE SHAPE OF THE STRUCTURE TO BE COMPLETED. THE FANS RUN THROUGHOUT THE CONSTRUCTION OF THE DOME. 3=POLYURETHANE IS APPLIED TO THE INTERIOR SURFACE OF THE AIRFORM.ENTRANCE INTO THE AIRFORM IS MADE THROUGH A DOUBLE DOOR AIRLOCKWHICH KEEPS THE AIR PRESSURE INSIDE AT A CONSTANT LEVEL. APPROXIMATELY 3 INCHES OF FOAM IS APPLIED.THE FOAM IS ALSO THE BASE FOR ATTACHING THE STEEL REINFORCING REBAR.
  24. 4=STEEL REINFORCING REBAR IS ATTACHED TO THE FOAM USING A SPECIALLY ENGINEERED LAYOUT OF HOOP(HORIZONTAL) AND VERTICAL STEEL REBAR. SMALL DOMES NEED SMALL DIAMETER BARS WITH WIDE SPACING. LARGE DOMES NEED LARGE BARS EITH CLOSER SPACING. 5=SHOTCRETE- A SPECIAL SPRAYMIX OF CONCRETE- IS APPLIED TO THE INTERIOR SURFACE OF THE DOME. THE STEEL REBAR IS EMBEDDED IN THE CONCRETE AND WHEN ABOUT 3 INCHES OF SHOTCRETE IS APPLIED,THE MONOLITHIC DOME IS FINISHED.THE BLOWER FANS ARE SHUT OFF AFTER THE CONCRETE IS SET.
  25. CASE STUDY OF R.C.C. DOME ST.FRANCIS XAVIER CHURCH, UDYAVARA IN UDUPI UMBRELLA SHAPED DOME (UNDER CONSTRUCTION)
  26. RING BEAM 40FT.(12.192M) • HT. OF DOME: 40FT.(12.192M) • DIA. OF DOME: 36FT.(10.9782M) REINFORCEMENT BARS OVER THE SCAFFOLDING M25 GRADE CONCRETE DOME • 4FT. (1.2192M) OF CONCRETE IS LAID PER DAY CASE STUDY OF R.C.C. DOME
  27. •DOME OF DHYANALINGA MEDITATION SHRINE IS SITUATED IN ISHA YOGA CENTRE, COIMBATORE. •THE DHYANALINGA IS A MULTI-RELIGIOUS MEDITATION SHRINE CREATED EXCLUSIVELY FOR THE PURPOSE OF MEDITATION. •THIS DOME OF 22.16 M DIAMETER HAS DESIGNED BY THE AUROVILLE EARTH INSTITUTE. •IT HAS BEEN BUILT FREE SPANNING IN 9 WEEKS. •THE WORK ON THE DOME STARTED THE 21ST NOVEMBER 1998 WITH THE CONSTRUCTION OF THE ENTRANCE VAULT, BUILT WITH GRANITE STONES AND ON A CENTERING DOME WITH LATERITE BLOCKS. •THE DOME HAD TO BE COMPLETED BEFORE A CERTAIN DEADLINE RELATED WITH HIS YOGIC PRACTICES AND PLANETARY ASPECTS CASE STUDY OF BRICK DOME
  28. • THE TIME REQUESTED FOR THE PRODUCTION, CURING AND DRYING OF THE BLOCKS (3 - 4 MONTHS COMPULSORY FOR ARCHES, VAULTS AND DOMES) WOULD HAVE BEEN TOO LONG. THUS, THE CHOICE WENT FOR FIRED BRICKS, WHICH WERE LAID WITH A STABILISED EARTH MORTAR. • THE FOUNDATIONS AND WALLS WERE BUILT IN RANDOM RUBBLE MASONRY WITH GRANITE STONES IN LIME MORTAR. •AROUND 214,000 FIRED BRICKS WERE LAID AND THE CONSTRUCTION SITE HAD A WORKING FORCE OF MORE THAN 220 . •THE LARGE AMOUNT OF FIRED BRICKS REQUIRED COULD NOT BE SUPPLIED BY THE SAME BRICK FACTORY. THEREFORE THE FIRED BRICKS CAME FROM ABOUT 20 DIFFERENT KILNS. AS A RESULT, THEY HAD DIFFERENT SIZES AND MOST OF THE TIME THEY HAD ODD SHAPES THEREFORE, NEARLY 200,000 BRICKS HAD TO BE CHECKED ONE BY ONE. •NO REINFORCE CONCRETE HAD BEEN USED IN ANY PART OF THE BUILDING: NEITHER FOR THE FOUNDATIONS, PLINTH NOR TIE FOR THE DOME. •THE DOME PRESENTS THESE FEATURES: • SECTION: SEGMENTAL ELLIPSE OF 22.16 M DIAMETER AND 7.90 M RISE. • THICKNESS: 4 COURSES FROM THE SPRINGER TO THE APEX: 53 CM, 42 CM, 36.5 CM AND 21 CM AT THE TOP. • WEIGHT: AROUND 570 TONS (BRICK DOME = ± 420 TONS + GRANITE STONE TO LOAD THE HAUNCHES = ± 150 TONS).
  29. DOME STABILITY STUDY •THEY DID NOT WANT TO USE CONCRETE RING BEAMS AND THEREFORE THE METHOD DOES NOT DEFINE THE OPTIMISED LINE OF THRUST IN THE DOME BECAUSE IT DOES NOT TAKE IN ACCOUNT THE CONCENTRIC FORCES, WHICH ARE ACTING IN A DOME AND ALLOW BUILDING IT WITHOUT SUPPORT. •FINALLY THE DOME WAS STUDIED LIKE A VAULT, WHICH IS MORE SENSITIVE TO A WRONG SHAPE THAN A DOME: IF A VAULT IS STABLE, A DOME WILL BE STABLE.WHEN THE OPPOSITE IS NOT NECESSARILY TRUE. •AS NO REINFORCED CONCRETE WAS USED FOR ANY TIE, IT WAS COMPULSORY TO GET THE RESULTANT OF THE TRUST WITHIN THE MIDDLE THIRD OF THE RING WALL AND THE FOUNDATIONS. TO DO SO, GRANITE STONES WERE USED TO LOAD THE HAUNCH OF THE DOME. MORTAR SPECIFICATIONS •WITH THE DOME RISING, THE MORTAR SPECIFICATION NEEDED REGULARLY TO BE ADAPTED: ADDING MORE SOIL, IN 3 STEPS, SO AS TO HAVE THE IDEAL ADHESION ACCORDING TO THE ANGLE OF THE LAYERS. •THE DIFFERENT MORTARS WERE OVER STABILISED SO AS TO GET A FAST SETTING AND STRENGTH: 13 TO 13.37% OF CEMENT AND 19% OF LIME.
  30. CONSTRUCTION DETAILS OF THE DOME STARTING THE ENTRANCE VAULT WITH GRANITE BLOCKS BLOCK TOUCHING THE SPRINGER AT THE INTRADOS KEYSTONE TOUCHING AT THE INTRADOS BEGINNING THE DOME DOME WITH THE LINGA AND THE ROPES TO CHECK THE ELLIPTICAL SHAPE LAYING KEYSTONES GROUTING THE STABILISED EARTH GLUE IN THE JOINTS FILLING TIGHTLY MORTAR WITH STONE CHIPS STARTING THE DOME WITH 29 CM THICK BLOCKS
  31. BONDS OF THE COURSES GRINDING THE PARTS OF THE COURSE WHICH ARE TOO HIGH CHECKING THE LEVEL OF THE COURSES CLOSING THE PIPE OF AN ACOUSTIC CORRECTOR PLASTERING THE PARTS OF THE COURSE WHICH ARE TOO LOW INSERTING THE PIPE FOR AN ACOUSTIC CORRECTOR TO ABSORB 220 HZ LOADING THE HAUNCHES WITH GRANITE STONES SMOOTHENING THE EARTH CONCRETE WITH A STABILISED EARTH PLASTER LAYING THE LAST COURSES DOME NEAR COMPLETION DOME AFTER COMPLETION
  32. THANK YOU!!!
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