कमान
कमान हे एक एखाद्या जागेच्या विस्तारासाठी करण्यात आलेले वक्राकार बांधकाम असते. त्याचे काम, त्यावरच्या वजनाचा भार सहन करणे अथवा न-करणे या दोन्ही प्रकारे राहू शकते.त्याला एक प्रकारचा dhyuw7iwuiaunwhhaट म्हणता येउ शकते किंवा घुमटाचा तो समानार्थी शब्द आहे,पण घुमट ही एक प्रकारची 'अखंड कमान' असा त्यात फरक करण्यात येतो.याचे बांधकाम मेसोपोटेमिया मध्ये ख्रिस्तपूर्व दुसऱ्या शतकात आढळले. ते विटांनी केलेले होते. त्याचा पद्धतशीर वापर रोमन लोकांनी सुरू केला. त्यांनी या पद्धतीचा बांधकामात मुक्तपणे वापर केला.
कमान हा एक शुद्ध दाबाचा प्रकार[भा १] आहे. त्यायोगे, त्यावरील असलेला भार हा जमिनीकडे बदली करण्यात यश मिळते.तसेच या बांधकामाद्वारे त्यामधील जागा मोकळी मिळते. तसेच या वास्तूचे सौंदर्यही वाढते. याचे कार्य बलाचे रूपांतर दाबात्मक-ताण[भा २] व खेच-ताण[भा ३] यात करून त्या बांधकामास स्थिर करणे असे असते. याची प्रवृत्ती ही नेहमीच, त्याचे दोन्ही आधार-बिंदूच्या बाहेर फाकण्याची राहते. कमानीची उंची कमी केली तर ही फाकण्याची प्रवृत्ती वाढते. त्याचे बांधकाम कोसळू नये म्हणून, त्यास आतील बाजूस आवश्यक असे अंतर्गत बंधक[भा ४] देऊन अथवा, बाह्य बाजूस भरीव बांधकाम करून ते टाळता येते.
स्थिर कमान विरुद्ध कब्जा(हिंज्ड) असलेली कमान
कमानीचे प्रकार
- त्रिकोनी कमान
- गोल कमान अथवा अर्ध-वर्तुळाकृती कमान
- पूर्णपणे अर्ध-वर्तुळाकृती नसलेली कमान
- दोन्ही भाग सम-नसलेली कमान किंवा रॅंपन्ट गोल कमान
- लॅंसेट पद्धतीची कमान
- Equilateral pointed arch
- सपाट-खंद कमान / जॅक आर्च
- त्रि-स्तरीय कमान अथवा चंद्रकोर कमान
- घोड्याच्या नालेच्या आकाराची कमान
- त्रि-केंद्रित कमान
- इलिप्टिकल[मराठी शब्द सुचवा] कमान
- ताठर अथवा न-वाकणारी कमान
- ऑगी पद्धतीची कमान
- विरुद्ध-ऑगी पद्धतीची कमान
- चार केंद्रे असलेली कमान अथवा ट्यूडर कमान
- पॅराबोला[मराठी शब्द सुचवा] आकाराची कमान
इतिहास
बांधकाम
जगातील विविध कमानींची चित्रदिर्घा
- Reconstructed Ishtar Gate of Babylon in Pergamon Museum, Berlin, Germany (2014)
- Arch of Augustus, Rimini, Emilia-Romagna, Italy (2015)
- Arch of Gallienus, Rome, Italy (2006)
- Arch of Hadrian, Athens, Greece (2013)
- Arch of Constantine, Rome, Italy, commemorating a victory by Constantine I in 312 AD (2007)
- The Arc de Triomphe, Paris, France; a 19th-century triumphal arch modelled on the classical Roman design (1998)
- Soldiers' and Sailors' Arch in the Grand Army Plaza, Brooklyn, New York City, New York (2007)
- Washington Square Arch, Greenwich Village, Manhattan, New York City, New York (2010)
- Gateway Arch in St. Louis, Missouri; a sculpture based on a catenary arch (2011)
- The dry stone bridge, so called Porta Rosa (4th century BC), in Elea, Province of Salerno, Campania, Italy (2005)
- Pont Flavien across the River Touloubre in Saint-Chamas, Bouches-du-Rhône, France (2008)
- Pont du Garde, a Roman aqueduct in Vers-Pont-du-Gard, Gard, France (2014)
- Bridge in Český Krumlov, Czech Republic (2004)
- Rialto Bridge over the Grand Canal in Venice, Italy (2011)
- Pont de Bercy over the River Seine, Paris, France, carrying the Paris Métro on its upper deck and a boulevard extension on its lower deck (2006)
- Grosvenor Bridge over the River Dee in Chester, Cheshire, England, UK (2007)
- Union Arch Bridge carrying the Washington Aqueduct and MacArthur Boulevard (formerly named Conduit Road) in Cabin John, Montgomery County, Maryland (2008)
- Arlington Memorial Bridge over the Potomac River in Washington, D.C. (2007)
- Francis Scott Key Bridge over the Potomac River in Washington, D.C. (2006)
- Woodrow Wilson Bridge carrying Interstate 95 (I-95) and the Capital Beltway over the Potomac River between Alexandria, Virginia and Oxon Hill, Maryland (2007)
- Margaret Hunt Hill Bridge over the Trinity River in Dallas, Texas (2012)
- Gateshead Millennium Bridge over the River Tyne, Newcastle upon Tyne, England, UK (2005)
- Tyne Bridge over the River Tyne, Newcastle upon Tyne, England, UK (2004)
- Hell Gate Bridge over the East River, New York City, New York,
- Sydney Harbour Bridge, Sydney, New South Wales, Australia (2010)
- Ludendorff Bridge over the Rhine River, Remagen, Germany, showing damage before collapse during the Battle of Remagen in World War II (1945)
- Eiffel Tower, Paris, France (2009)
- Arch supporting the Eiffel Tower, Paris, France (2015)
- The Second Wembley Stadium in London, built in 2007 (2007)
- The First San Mamés Stadium, in Bilbao, arch built in 1953, demolished 2013 (2013)
- St Pancras railway station, London, England (2011)
- Train shed in St Pancras railway station, London, England (2010)
- Train shed in Victoria Station, London, England (2006)
- Lucerne railway station, Switzerland (2010)
- Train shed in Lucerne railway station, Switzerland (2016)
- Central railway station, Frankfurt, Germany (2008)
- Train shed in Central railway station, Frankfurt, Germany (2005)
- Grand Central Terminal, Manhattan, New York City, New York (2008)
- Arches in Main Concourse, Grand Central Terminal, Manhattan, New York City, New York (2014)
- Haus der Kulturen der Welt, Berlin, Germany (2011)
- The Colosseum in Rome, Italy (2013)
- Arches inside the Colosseum in Rome, Italy (2005)
- Stonework arches seen in a ruined stonework building – Burg Lippspringe, Germany
- Several arches at the Casa Simón Bolívar in Havana, Cuba
- Kings College, University of Cambridge in Cambridge, England (2007)
- Arches in dining hall at Kings College, University of Cambridge, Cambridge, England (2007)
- Memorial Hall, Harvard University, Cambridge, Massachusetts (circa 1897-1924 photochrom post card)
- Arches inside transept, Memorial Hall, Harvard University, Cambridge, Massachusetts (2016)
- Arches inside Annenberg Hall, Memorial Hall, Harvard University, Cambridge, Massachusetts (2016)
- Healy Hall, Georgetown University, Washington, D.C. (2009)
- Arches inside Healy Hall, Georgetown University, Washington, D.C. (2010)
- Central Tower, Erasmus Hall High School, Brooklyn, New York City, New York (2013)
- Neuschwanstein Castle, Bavaria, Germany
- Arches in throne room of Neuschwanstein Castle, Bavaria, Germany (1886 photochrom print)
- Arches in the nave of the church in monastery of Alcobaça, Portugal
- North facade of Chartres Cathedral, Chartres, France (2008)
- Arches in choir of Chartres Cathedral, Chartres, France (2013)
- Western facade, Westminster Abbey, City of Westminster, London, England (2013)
- Arches in nave of Westminster Abbey, City of Westminster, London, England (2006)
- Washington National Cathedral in Washington, D.C.
- Arches inside the Washington National Cathedral, Washington, D.C. (2005)
- Main facade of St. Peter's Basilica, Vatican City, Rome, Italy (2015)
- Interior arches in St. Peter's Basilica, Vatican City, Rome, Italy (2009)
- Hagia Sophia in Istanbul, Turkey (2013)
- Arches inside the Hagia Sophia in Istanbul, Turkey (1983)
- Arches inside the western upper gallery, Hagia Sophia, Istanbul, Turkey (2007)
- Interior arches in Masjid al-Haram, Mecca, Saudi Arabia (2008)
- Roof of Masjid al-Haram, Mecca, Saudi Arabia (2008)
- Dome of the Rock, Old City of Jerusalem (2010)
- Arches inside Dome of the Rock, Old City of Jerusalem (2014)
- Taj Mahal in Agra, Uttar Pradesh, India (2009)
- Entrance to grounds of Taj Mahal, Agra, Uttar Pradesh, India (2004)
- East side of United States Capitol in Washington, D.C. (2005)
- Arches in corridor of United States Capitol, Washington, D.C. (2006)
- Thomas Jefferson Building, Library of Congress, Washington, D.C. (2008)
- Arches in Main Reading Room, Thomas Jefferson Building, Library of Congress, Washington, D.C. (2009)
- Arches in Great Hall, Thomas Jefferson Building, Library of Congress, Washington, D.C. (2007)
- Art Deco arches on Chrysler Building, Manhattan, New York City, New York (2005)
- New York Public Library Main Branch, Manhattan, New York City, New York (2016)
- Arches inside entrance of New York Public Library Main Branch, Manhattan, New York City, New York (2012)
- Metropolitan Museum of Art, Manhattan, New York City, New York (2012)
- Arches in Great Hall, Metropolitan Museum of Art, Manhattan, New York City, New York (2012)
- Winter Palace, Hermitage Museum, St. Petersburg, Russia (2016)
- Arches near Jordan Staircase, Winter Palace, Hermitage Museum, St. Petersburg, Russia (2015)
- Arches in Pavilion Hall, Small Hermitage, Hermitage Museum, St. Petersburg, Russia (2015)
- Cour Carrée, Louvre Palace, Paris, France (2010)
- Arches in Salle du Manège, Louvre Palace, Paris, France (2007)
- Palace of Versailles, Versailles, Yvelines, France (2012)
- Arches in Galerie des Batailles, Palace of Versailles, Versailles, Yvelines, France (2013)
- Arches in Hall of Mirrors, Palace of Versailles, Versailles, Yvelines, France (2011)
- Palace of Westminster, City of Westminster, London, England (2010)
- Arches in Westminster Hall, Palace of Westminster, City of Westminster, London, England (2011)
- Arches in St. Stevens Hall, Palace of Westminster, City of Westminster, London, England (2007)
- Aljafería Palace in Zaragoza, Spain (2005)
- Horseshoe arch inside Aljafería Palace, Zaragoza, Spain (2004)
- Multifoil arches inside Aljafería Palace, Zaragoza, Spain (2004)
- Catenary arches inside Casa Milà in Barcelona, Spain by Antoni Gaudí
- Rajasthani style arches inside the 16th century City Palace, Udaipur, India
- Main façade of the Itamaraty Palace in Brasília, Brazil, decorated with many arches.
- Smithsonian Institution Building ("The Castle"), Washington, D.C. (2007)
- Arches inside the Smithsonian Institution Building ("The Castle"), Washington, D.C. (2012)
- National Building Museum (formerly Pension Building), Washington, D.C. (2005)
- Arches inside National Building Museum (formerly Pension Building), Washington, D.C. (2007)
- Main facade of the Old Post Office Pavilion (now the Trump International Hotel) in Washington, D.C. (2012)
- Front entrance of Old Post Office Pavilion in Washington, D.C. (2006)
- Arches inside Old Post Office Pavilion in Washington, D.C. (2009)
- Arches in Merzouga, Morroco (2011)
- Crypt of the Popes in the Catacomb of Callixtus, Rome, Italy (2007)
- Chinese Eastern Han Dynasty (25–220 AD) tomb chamber (2008)
- Entrance to Washington family tomb at Mount Vernon, Fairfax County, Virginia (2014)
- Natural Bridge in Rockbridge County, Virginia (2014)
- Landscape Arch, Arches National Park, Utah (2009)
- Double O Arch, Arches National Park, Utah (2007)