Ryu NODA, Takanobu SASAKI, Tomohiro CHIDA, Takato INOUE, Toshimasa HARATA and Yasuhiro MIURA
In Akita Prefecture, to promote the demand expansion of the Japanese cedar
produced in Akita Prefecture and to activate the local areas by centering timber
industry, various civil engineering structures used timber have been proposed
and developed, and have been actually constructed. Wooden check dam is one of
these, there are two kinds of wooden check dams called gAkita standard".
One of which is gall wood type" dam composed only wood members and lag
screws, and usage rate of timber is up to 90%. Another is ghybrid dam"
packed the thinned wood and gravels in the steel flexible frame, and usage rate
of timber is about 80%. In this study, we presented the details of all wood
type wooden check dam and hybrid type. In all wood type wooden check dam, we
reported results of the strength test of joint used lag screw and failure test
of real]size dam specimen, which were conducted before construction, and monitoring
study at construction site. In addition, we accessed the strength property,
usage rate and cost performance of each Akita standard dam by comparing the
crib dam which ever have spread in the whole country. In the failure test, it
was shown that the specimen have safety rate 10 for the design load. With regard
to monitoring study, from actual water level inside dams, it found that phreatic
line was lower than design position. In comparison with the crib dam, although
for used amount of timber Akita standard dam was very effective, for cost there
was no difference.
Key wordsFAkita standard dam, all wood type wooden check dam, hybrid type wooden check dam,Japanese cedar, lag screw