Research and Development on the Woden Building System Using square Lumber

Research Project

Project/Area Number	08455279
Research Category	Grant-in-Aid for Scientific Research (B)
Allocation Type	Single-year Grants
Section	一般
Research Field	Town planning/Architectural planning
Research Institution	TOKYO METROPOLITAN UNIVERSITY
Principal Investigator	FUKAO Seiichi Graduate School of Engineering, TOKYO METROPOLITAN UNIVERSITY,Professor, 工学研究科, 教授 (90112482)
Co-Investigator(Kenkyū-buntansha)	TSUNODA Makoto Graduate School of Engineering, TOKYO METROPOLITAN UNIVERSITY,Research Associate, 工学研究科, 助手 (10180035)
Project Period (FY)	1996 – 1998
Project Status	Completed (Fiscal Year 1998)
Budget Amount *help	¥6,300,000 (Direct Cost: ¥6,300,000) Fiscal Year 1998: ¥1,400,000 (Direct Cost: ¥1,400,000) Fiscal Year 1997: ¥2,000,000 (Direct Cost: ¥2,000,000) Fiscal Year 1996: ¥2,900,000 (Direct Cost: ¥2,900,000)
Keywords	wooden structure / square lumber / boxed timber / building system for house / erection / joint / column / beam
Research Abstract	In Japan, plenty of timbers of small diameter such as cedar and cypress which were planted after the World War II, will come to the market in the near future. But the demand for those timbers which are produced to be use as post, is decreasing gradually, because the numbers of wooden house construction become smaller and smaller. The purpose of this study is to develop the new building system that makes use of wood's characteristics using square timbers of small diameter as not only structural components but as finishing members. Surveys were done on the actual conditions of stock of cedar trees in Japan by the documents of the Forest Agency. The feasibility of such building system was studied. We designed the model of building system using plenty of square timbers. The size of posts and beams of that model is 120mm x 120mm and size of the model itself is 3600mm * 3600mm (8 tatami room tea) Eight non-skilled labors could build up the full scale model in 6 hours, and that constructability was near to our target. In case of the columns at 3cm gap, new jointing system between two columns using polyurethane was developed and the experiment to assemble them were carried on. The gap of columns was enlarged to 6cm from 3cm, and several kinds of wall construction methods were developed and examined. The warp and shrinkage were observed but absorbed with the details carefully designed. On the basis of those examinations, the trial designs for the building type which little bit larger than house applying the new building system were made.