SLOPE FAILURES AT YOKOWATASHI AND NAGAOKA COLLEGE OF TECHNOLOGY DUE TO THE 2004 NIIGATA-KEN CHUETSU EARTHQUAKE AND THEIR ANALYTICAL CONSIDERATIONS

SOILS AND FOUNDATIONS

KEIZO UGAI¹  KIYOSHI FUKUTAKE⁵  AKIHIKO WAKAI¹  HIDEAKI NAGAI⁶  KUNIHIRO HIGUCHI²  ATSUO ONOUE⁴  HIROYUKI HOTTA⁵  SEIICHIRO KURODA³ 

[1] Department of Civil Engineering, Gunma University;Kuroiwa Survey and Design Office;National Institute for Rural Engineering;Department of Civil Engineering, Nagaoka National College of Technology;Institute of Technology, Shimizu Corporation;Science System Division, CRC Solutions Co., Ltd.

关键词: bedding plane;    cutting and filling ground;    dip surface;    earthquake;    effective stress;    finite element analysis;    organic soil;    shear strength;    slope failure;    (IGC: D6/E6/E8);   

DOI  :  10.3208/sandf.46.751

学科分类：建筑学

来源: Japanese Geotechnical Society / Jiban Kogakkai

【 摘 要 】

References(18)Cited-By(5)Numerous natural or artificially embanked slope failures were caused by the 2004 Niigata-ken Chuetsu Earthquake. Characteristics of large scale natural slope failures that occurred at folding hills, river terraces, etc, were classified from a geometric structural view point. It was noted that surface failures occurred at steep cliffs and landslides occurred at gently slanting dip slopes. The cause of a landslide in a dip slope at Yokowatashi, Ojiya city was analytically investigated based on cyclic shear test results of the laminar sand at the bedding plane. This study revealed that the safety factor of the slope stability became momentarily smaller than 1.0 several times during the earthquake due to the small undrained shear strength of the tuff sand seam and the landslide behavior was simulated by an elasto-plastic dynamic finite element analysis where the strength decrease of the sand seam with increasing number of cycles was taken into consideration. The cause of destructive damage of a school building at Nagaoka National College of Technology (NNCT) was next examined by another elasto-plastic dynamic FEM. From the analysis results, it was confirmed that the building was pulled and twisted by the landslide of the bank shotcrete accompanied with pile fracture.

【 授权许可】

Unknown