Vol. 520117 Management and Maintenance of Shirasu Slopes in Historic Mountain Castles Constructed in Middle Age, Kagoshima Prefecture 1 2 3 3 4 5 5 6 6 Ryosuke Kitamura, Haruki Shigeta, Takayuki Yotsuda, Masayuki Tabata, Mamoru Yamada, Shiro Yonemoto, Yoshiaki Okubo, Tetsuro Nakashima and Norihiro Fujii 1 890-0065 1-21-40 Professor, Kagoshima University, Dept. of Ocean Civil Engineering 2 JR812-0011 32521 JR Kyushu (Formerly Graduate Student, Kagoshima University, Dept. of Ocean Civil Engineering) 3 890-0065 1-21-40 Graduate Student, Kagoshima University, Dept. of Ocean Civil Engineering 4 SPTECYAMADA 363-0008 1344-1 President of SPTECYAMADA 5 899-7192 2-1-1 Board of Education in Shibushi City 6 895-8650 3-22 Board of Education in Satsuma-Sendai City In Kagoshima Prefecture there are a lot of hisroric mountain castle sites where castles were constructed on the Shirasu ground in the Japanese middle age (12~16 Century). Some of them have been designated as histroric sites by the Agency for Cultural Affairs. Shirasu is geologically defined as the non-welded part of pyroclastic flow deposits and has a feature that it is easy to be eroded by the flow of rainwater although Shirasu slopes can keep to be a steep inclination angle under the dry conditon. Therefore we can find a lot of Shirasu slope failures in the historic mountain castle sites as the Shirasu slope has been weathered for several hundred years, and trees and glasses are now growing randomly. In this paper the management and maintenace of Shirasu slope in Historic Shibushi and Kiyoshiki Casttles which were designatd as historic sites by the Agency for Cultural Affairs are discussed from a view point of geotechnical engineering. Keywords : :mountain casttle, Shirasu slope,management and maintenance, Diplazium subsinuatu,bamboo and wooden chips 1945 1993 2004 2005 2009 1 1
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30 70 5 5 2.5 6 1) 37pp.1-4 2010 2) 22 pp.397-3982011 6