Issue 30

G. Jingran et alii, Frattura ed Integrità Strutturale, 30 (2014) 495-501; DOI: 10.3221/IGF-ESIS.30.60 495 Degradation assessment of waterlogged wood at Haimenkou site Gao Jingran, Li Jian Northeast Forestry University Material Science and Engineering institute, Ha’erbin, Heilongjiang 150040 E-mail:48682171@qq.com Qiu Jian Southwest Forestry University School of materials engineering, Kunming, Yunnan 650024 E-mail:qiujianswfu@foxmail.com Guo Menglin Iowa State University, Iowa, U.S.A) A BSTRACT . Haimenkou site is the largest railing-enclosed wooden architecture settlement site on the waterfront in current China. This research conducts degradation assessment of waterlogged wood at Haimenkou site with various methods, including maximum moisture content analysis, basic density analysis, shrinkage measurement, swelling analysis, chemical composition analysis, measurement of compression strength parallel to grain, SEM microstructure analysis and measurement of crystallinity, providing scientific guidance for the subsequent formulation of proper methods of reinforcement. K EYWORDS . Haimenkou site; Waterlogged wood; Degradation assessment. I NTRODUCTION aimenkou site locates at 1 km northwest to Haimenkou village in Diannan, Jianchuan, Dali, Yunnan province, whose GPS coordinates are 99°33´~100°33´ E and 26°12´~26°41´ N, adjoining the northwest bank of Haiwei River at the southwest outfall of Jian lake. During the archaeological excavation, a huge area of wooden architecture relics and abundant cultural relics such as pottery, bronze ware, stoneware and ironware were discovered. C14 analysis shows they could be dated back to 5300~2500 years ago, counted as a Neolithic or Bronze-age settlement site. Since 1957 the site has been unearthed for three times, the third one in 2008 excavating more than 4000 timber piles in an excavation unit of 1395 square meters. Meanwhile, the site area was measured to be 140000 m 2 , and the concentration area of timber piles was measured as 20000-25000 m 2 , making it the largest railing-enclosed wooden architecture settlement site on the waterfront in current China. Its rareness on earth provides a precious case for analyzing types of Chinese prehistoric settlements, and is of great value on the study of social development history and ethnic history of Yunnan Province. Professor Qiujian from Southwest Forestry University has conducted random sampling test on unearthed wood piles, finding most of the tree belonged to Pinus yunnanensis. Therefore this research chooses waterlogged wood Pinus yunnanensis as samples to develop degradation assessment, trying to provide scientific guidance for the subsequent formulation of proper methods of reinforcement. H