2020 Volume 85 Issue 776 Pages 2129-2138
To provide an emergency temporary housing in a short time is important for the victim of natural disaster. In Kansai Area, we have to make preparation for Nankai Trough Earthquake which is expected in next a few decade. At the Great Hanshin·Awaji Earthquake in 1995, most of emergency temporary housing were built only by the members of Japan Prefabricated Construction Suppliers and Manufacturers Association(JPA) as prefectural government and JPA made the agreement to supply emergency temporary housing in case of those disaster. At the Great East Japan Earthquake in 2011, affected area was so large and it was hard to build them in a short time. Therefore it took about more then 6month to finish building emergency temporary housing. Still, JPA's prefabricated temporary housing take major role in supplying temporary housing. There must be quicker, more efficient way to supply housing, specially in local areas.
In this study, we have a local builder in proposed site of a Nankai Trough Earthquake, not members of JPA, to build the JPA's emergency temporary housing with construction manual we made fur them to examine the workability, time difference from JPA builders, difficulty the local builders face in the construction process. Those date would help to give oppotunity to local builders to build emergency housings and diversifying the way of providing the temporary houses.
At first construction experiment, Daiwa lease co., JPA's major member and have vast experience of supplying temporary housing, built a two housing unit, on the land owned by the Hirogawa town, Wakayama prefecture. We measure the hours by every kind of works at process of construction, and recorded every workers move and what kind of work they did at construction site. Next step was to make the construction manual for local builders who has no experience to build prefabricated housing. The manual describe every working process, working details. We also made a bolts list because so many types are used for the flame and brace.
At second construction experiment, local builders tried to build the prefabricated housing with the manual we edited for them. Local builder took 89.7h in construction stage, while special contractor Daiwa Lease Co. ltd.(D) took 38.5h. In interior work stage, local builder took 104.5h, slightly shorter than the "D"'s working time of 111.9h. In equipment work stage, local builder rook 14.5h, compare to "D"'s working time of 36.5h. Time difference occurred only in construction stage. There were reasons of the delay fur local builder. One was level of proficiency. Second reason was mistakes the local builder made. The third was troubles in parts choice. The fourth was lacking of instruction in the new manual. Mistakes happened in sills, inner beans, roof beams, wall panels, windows. Troubles in parts choice occured at sills, celling, and roof where each stages had to assemble many types of small parts.
In conclusion, local builder could have build the emergency temporary housing, even though the time difference was big, specially at construction stage, difference were 51.2h. The local builder made several mistakes in construction stage, but improvement to the manual could reduce those mistakes, and troubles in part choice. Those mistakes and troubles could happen because that was their first trial to build it.