2021-08-02T19:20:54Zhttps://soar-ir.repo.nii.ac.jp/oaioai:soar-ir.repo.nii.ac.jp:000119052021-07-05T00:36:58Z1169:1170沈降天秤法と比重計法の組合せによる泥質砂堆積物の粒度分析法Grain-size analysts COmbined settling tube method with hydrometer method for muddy sand sediments岸, 誠一公文, 富士夫grain-size analysishydrometersettling tubesievingweight correctionGrain-size analysis of muddy sand or sandy mud is a matter of trouble, because the sed1- ments abundantly include both sand and clay grain size which behave differently in principle. The analysis by a single method needs a very long time and/or a large labor for one specimen. The new procedure proposed here is a combination of a settling tube method for sandy fractions and a hydrometer method for muddy fractions. The hydrometer analysis is performed according to an ordinary procedure. Then wash the sample on a 4.5-phi standard sieve. Dry the fractions rested on the sieve, and weigh it. After then, analyze the coarse fractions by a settling tube method. The settling tube method is a newly-formed system which uses an electric balance and a computer. Make the two cumulative frequency curves, and combine them by ca1- culation. Theoretically, both curves should fit at 4.0 phi of settling-size grade, on the basis of the detailed research of effects by 4.5-phi sieving, Both curves, however, often differ slightly at 4.0 phi. Therefore, they are shifted to each other at 4.0-phi grade by changing the total weight of the used sample, namely "weight correction". This procedure takes 4 days to analyze 15 samples from coarse-grained sand to clay.Article堆積学研究会報. 38:101-106 (1993)堆積学研究会1993jpnjournal articlehttp://hdl.handle.net/10091/3723https://soar-ir.repo.nii.ac.jp/records/119050285-1555AN10553692堆積学研究会報38101106https://soar-ir.repo.nii.ac.jp/record/11905/files/taisekigaku-38.pdfapplication/pdf819.1 kB2015-09-28