ブックタイトル「煉瓦造建造物の保存と修復」英語版

概要

「煉瓦造建造物の保存と修復」英語版

Recent Movements in Seismic Reinforcement ofBrick Masonry Structures in JapanSatoshi NishiokaAgency for Cultural Affairs, Cultural Properties DepartmentArchitecture and Other Structures Division, Specialist for Cultural Properties○Building Standard Act…This is the law applied to buildings in general in Japan.○Guidelines for Assessing Seismic Resistance of ImportantCultural Properties (Buildings) set by the Japanese Agencyfor Cultural Affairs…A specialized approach and diagnosis methods havebeen set for nationally designated Important CulturalProperty structures which are exempt from complying tothe Building Standard Act. This is aimed mainly attraditional wood-frame structures.Required seismic performance…Standard to maintain performance：Will maintain its function in a large-scale earthquakeStandard to ensure safety：Will not collapse in a large-scale earthquakeStandard to enable recovery：May collapse in a large-scale earthquake but its valueas a cultural property can be recovered. Forstructures such as shrine worship halls where thegeneral public do not enter.Introduction of the Building Standard ActAimTo set minimum standards regarding the building’ssite, structure, facilities, and use in order to protectthe lives, health, and assets of the people and topromote well-being of the publicStructural performanceBuildings need to be structurally sound to supportthe its own weight, expected loads, snow load; wind,soil, and water pressures; as well as earthquakes andother forms of vibration and shockRegarding masonry structuresConstruction of buildings exceeding 13m in height or9m in eave height requires certification by the Ministerof Land, Infrastructure, Transport and TourismFor those under the above heights, there are detailedrules for specifications regarding wall length, wallthickness, beam placement, and limits on openings, etc.→Except for small-scale structures, new masonryconstruction is very rareGuidelines for Assessing Seismic Resistance ofImportant Cultural Properties (Buildings)Aim…To protect the value as a cultural property and ensuresafety at the time of earthquakesInput seismic motion…Large-scale and middle-scaleearthquakes as defined in the Enforcement Order forthe Building Standard ActRegarding masonry structures:Although details are not specified, effective methods tomeet the building’s structural characteristics should beemployed for seismic analysisInput seismic motionLarge-scale movements…“Earthquakes which occur very rarely”Seismic load of the greatest scalePresumably occur once very 500 yearsIntensity 6 upper on the Japanese seismic scaleStatic horizontal load…equals the same load as that of the building itself (1.0 G)Pseudo-dynamic test…Standard acceleration response spectrumMiddle-scale movements…“Earthquakes which seldom occur”Maybe encountered few times during the life of a buildingPresumably occur once very 50 yearsIntensity 5 on the Japanese seismic scaleStatic horizontal load…equals 20% of load of the building itself (0.2 G)Pseudo-dynamic test…Standard acceleration response spectrum64Chapter 5 Recent Movements in Seismic Reinforcement of Brick Masonry Structures in Japan