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

? Form of the buttressStudies for designing the buttress were undertakencooperatively by cultural property architectural conservatorsand the architectural design office (figure 7-4).If the buttresses were to be made in a simple triangularshape, the area required for attachment onto the structurewould be comparatively large, and therefore, a form ofbuttress without supporting columns was studied. Finally,so as to refine the design, the slope at the upper end ofthe buttress was matched with that of the roof, then at adistance away from the wall (the position of the east-westwall on the north protruding side: about 2.7 meters), it wasshaped to head straight down toward the ground.Also, in order to simplify the form, H-section steel wascovered with a box form; the thickness at the top end of thebuttress where it meets the building was studied, varyingthe size from 50%, 80%, to 100% in full-scale models forstudying on-site, actually placing them by the structure. Inthe end, a form of 80% thickness was selected (photos 7-4,7-5).In addition to its shape, surface finish was also studied.Because there was fear of deterioration due to corrosion,metal spraying of zinc aluminum alloy which proved to beeffective against rust and corrosion was adopted as a surfacefinish. In choosing the tone of the finish, an inorganicappearance of a color different from brick or stone waspreferred and thus it was decided to adopt the charcoal graycoloring of the material itself.? Other structural reinforcementAt the Former Yamagata Prefecture Assembly Hall,reinforcement other than buttressing that was planned andexecuted is as follows.1 Steel frame horizontal trusses were introduced in theupper floor and the east and west lean-to on the first floorof the south building as well as above the rostrum.2 Cracks in brick were injected with epoxy resin forreinforcement.3 The south wall of the south building and the wallnorth of the rostrum were inserted with steel bars forreinforcement against out-of-plane bending.4 Steel bars were inserted in the horizontal direction of thecorridor arch of the south building.5 Anchor bolts were installed in the brick wall to preventthe floor joist of the south building from falling. The floorstructure was connected to walls with metal fixtures.6 Horizontal corner bracing was placed in the roof structureof the assembly hall.photo 7-4 Placing full-scale models for structural reinforcement（photo provided by：Professor Emeritus, Tsutomu Kimura of Nagaoka Instituteof Design）photo 7-5 West side of the Assembly Hall during buttress reinforcement work(the two-storied structure to the right is the south building)（photo provided by：Professor Emeritus, Tsutomu Kimura of Nagaoka Institute of Design）figure 7-5 Section of the Assembly Hall after structural reinforcement（Reference：重要文化財山形県旧県庁舎及び県会議事堂保存修理工事報告書1旧県会議事堂編）? OverviewAt the Former Prefectural Assembly Hall, the earlier planto reinforce the structure from the inside was revised,following findings through surveys undertaken during thedismantlement process for restoration, to place steel framereinforcement on the outside. During this process, variousstudies to minimize effects on brick walls were made. Inaddition, regarding repairs of damaged brick, as has beenexplained in 5-3, different methods were carefully chosenaccording to the degree of deterioration. This restoration isalso the first case in which vertical holes were made in brickwalls for restoration.111