An experimental study of shear strength and compressiblity of Mai-liao sand

• Main Authors: Po-San Wang, 王柏善
• Other Authors: Dao-Wei Feng
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/87999705712262042977

碩士 === 中原大學 === 土木工程研究所 === 102 === Literature data show that Taiwan Midwest sand containing mica mineral particles, the average indoor sand only a limited mechanical testing of soil samples was measured mechanical properties, not enough to understand the composition of the mineral content of sand size and relative density of the internal friction angle and compression Index of. In this study, direct shear tester and one-dimensional compaction tester for laboratory tests, including tests Mai-liao sand and Ottawa sand standard sand, and 10% levels of coarse muscovite (<# 40) or thin clouds mother (<# 325), in order to simulate in situ possible, Mai-liao sand itself contains mica and mica after adding a small amount more in line with the situation Mai-liao sand areas, and in the Ottawa sand mica added, so that the two different kinds of sand particle shape of comparison, and to explore the relative impact of changes in density and normal stress shear strength parameters of sand and compressibility of. The test results show that the secant angle of internal friction with the normal stress of taking the case to improve and reduce the cohesion of zero. In the low forward stress (9.06kPa), the Mai-Liao sand initial relative density of 21%, 77%, 10% Mai-liao coarse sand mixed muscovite 23%, 62%, mixed 10% to 40% of fine muscovite, 76 % of the sample, its secant friction angle was 33.2o, 41.6 o, 34.7o, 38.2 o, 32.29 o, 35.2 o, Ottawa sand relative density of 27%, 72%, 10% Ottawa crude mixture of standard sand muscovite 35%, 67%, 10% mixture of fine muscovite 36%, 71% of the sample, its secant friction angle was 35.8 o, 44 o, 31.9 o, 42.6 o, 35.4 o, 37.8 o. Thus Mailiao Ottawa sand and sand friction angle with the relative density of the upgrade and enhance the positive stress in the same secant and mixed muscovite secant angle of internal friction decreases, while the mixed fine muscovite secant friction angles are slightly lower than the sample of mixed coarse muscovite; while at higher normal stress Mailiao Ottawa sand and sand is also true, and its mix of fine muscovite samples secant friction angles are slightly larger than the mixed coarse clouds mother of the sample. In this study, the fifth -order direct shear loading tests (the final normal stress = 350.44kPa) the proceeds of the void ratio changes obtained secant compression index ; take advantage of one-dimensional compaction meter Mai-liao sand relative density of 70% , Ottawa sand 67% of its secant compression index were 0.069,0.020 , and direct shear tests measured the relative density of the Mai-liao sand 55% to 91% of its secant compression index was 0.121 ~ 0.056 , Ottawa sand 67% to 96% , compared with 0.051 ~ 0.030 , which Yan-gzhen Bang ( 2009 ) the use of one-dimensional compaction meter measured the Mai-liao sand compression index was 0.096 and 0.023 Ottawa sand , compared to the use of direct shear tests measured compression index than with indoor unidirectional compaction the measured value of the index is slightly compressed . Mai-liao sand Ottawa sand mixed with coarse and fine muscovite , secant compression index to improve as the relative density decreases as the compression index secant upgrade and enhance the positive stress test results show samples of mixed coarse muscovite secant compression index is greater than its mix of fine muscovite samples , which had mixed coarse mica would increase soil porosity , so there is a greater mix of coarse mica compression .