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No.75 (2003/3) >

 
Title :Fault analysis around Himalaya by means of 2 dimensional finite element method.
Authors :Howladar, M. Farhad
Hayashi, Daigoro
Authors alternative :林, 大五郎
Issue Date :Mar-2003
Abstract :We examined the nature of stress around the Himalaya via numerical simulation using the 2 dimensional plane strain finite element models with elastic rheology. Mohr-Coulomb failure criterion also adopted to analyze the relationship between stress distribution and its influence on forming faults around the Himalaya. From this point of view, we presented three finite element elastic models and considered convergence displacement that is subjected along the SW-NE horizontal direction. Results point out that the convergence displacement boundary conditions and elastic properties of rock control the distribution, orientation, magnitudes and intensity of stress during the experiments. Some interesting features of our models are: (1) principle stresses are mainly compressive; (2)σ_1 directs vertically in deeper part and horizontally in the upper part of all layer; (3)σ_2 exhibits horizontal direction in the deeper part and vertical in the upper part; (4) magnitudes of both stresses are relatively high in the deeper part compared with the shallower part; (5)some tensional stresses are displayed in the upper part of Higher Himalayan region; (6)most of the elements are failed in layer 2 (Sub-Himalaya) and in the upper part of layers, 1 (Pre-Cambrian Basement), 4 (Higher Himalaya) and 5 (Tethys Himalaya). These features allow us to infer that the nature and direction of compressive and tensional principle stresses are responsible for forming thrust and normal faults in these layers, respectively and they are intensely concentrated along Sub-Himalaya and upper part of other layers. The results from our numerical experiments are in agreement with the seismicity and focal mechanism solutions of earthquakes in the study area.
Type Local :紀要論文
ISSN :0286-9640
Publisher :琉球大学理学部
URI :http://hdl.handle.net/20.500.12000/2619
Citation :琉球大学理学部紀要 = Bulletin of the College of Science. University of the Ryukyus no.75 p.19 -53
Appears in Collections:No.75 (2003/3)

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