Co-Investigator(Kenkyū-buntansha) |
NODA Toshihiro NAGOYA UNIV., GEOTECH. & ENV. ENG., CIVIL ENG., ASSOC. PROF., 工学研究科, 助教授 (80262872)
NAKANO Masaki NAGOYA UNIV., CIVIL ENG., ASSOC PROF., 工学研究科, 助教授 (00252263)
ASAOKA Akira NAGOYA UNIV., CIVIL ENG., PROF., 工学研究科, 教授 (50093175)
KANEDA Kazuhiro NAGOYA UNIV., CIVIL ENG., RESEARCH ASSOCIATE, 工学研究科, 助手 (30314040)
YAMADA Eiji NAGOYA UNIV., GEOTECH. & ENV. ENG., CIVIL ENG., ASSIS. PROF., 工学研究科, 助手 (00293647)
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Research Abstract |
As one of countermeasures against possible liquefaction on sandy ground, sand compaction pile (SCP) method is widely used. However, in construction projects even in densely population areas, the "SCP method with less vibration" by cylindrical expansion that causes less undesirable effects, such as vibration and noise, is developed and used recently. In this research, a numerical study was done by using soil-water coupled elasto-plastic finite deformation analysis, mainly to investigate its mechanism of the compaction by cylindrical expansion and to grasp the ground improvement method's peculiarity considering loading history, initial ground conditions etc. The findings of the study are summarized as follows : a) Even a sandy ground in comparatively dense is improved by cavity expansion without vibration, because the effective stress path of sand elements is moving up with hardening due to plastic compression under the critical state line. b) The compaction effect is dependent on boundary conditions, e.g. expansion rate, permeability, etc. and initial conditions, e.g. stress, overconsolidation, degree of structure. c) These findings could lead to, for instance, selecting the most suitable compaction machine corresponding to ground conditions and material properties such as grain size gradation.
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