2023-02-04T03:19:35Z
https://u-ryukyu.repo.nii.ac.jp/oai
oai:u-ryukyu.repo.nii.ac.jp:02002264
2022-02-14T21:30:38Z
1642837622505:1642837957109:1642837976383
1642838403551:1642838406414
Stress Distribution and Fault Development Around Nepal Himalaya by Means of Finite Element Method
Alam, Md. Mahmudul
Hayashi, Daigoro
林, 大五郎
There are a number of methods to analyse geological structures. Finite element method is one of them. Numerical modeling based on finite element analysis is an effective tool for studying the elastic behaviors of earth's crust due to tectonic movement. This study describes how to use an advanced numerical modeling technique, the finite element method, to compute rock deformation and to predict stress and fault development as a function of material properties, cohesion and friction angle. Stress distribution and fault development of 2 dimensional plane strain FEM models of four Himalayan cross sections are described. SW (south west) to NE (north east) horizontal shortening up to maximum 375 m (equivalent displacement at 7.5 cm/yr of 5000 yr) is applied at the southwestern end of the cross-sections. Proposed models show that the direction of maximum principal stresses (σ_1) are horizontal along the shallower part of all the models. Variation of the velocity boundary condition indicates the changes of direction of principal stresses along the deeper part while that along the shallower part remain unchanged.\nAccording to the Mohr - Coulomb criterion, failure is observed along the shallower part of Siwalik, Tethys and Granitic layer, and a very few near the surface of MBT, MCT and STDS. Failure has not occurred in the deeper part of Higher Himalaya and Lesser Himalaya, inspite of changing physical parameters of rock formations, because of the hydrostatic condition that is observed along the models. Previous studies on focal mechanism solutions of earthquakes in the Himalayan region provide the existence of thrust faults along its EW stretching with one plane dipping gently north beneath the Himalaya. Simulation shows the same distribution of thrust faults along the upper part of the models as shown by the focal mechanism solutions.
紀要論文
http://purl.org/coar/resource_type/c_6501
琉球大学理学部
VoR
http://hdl.handle.net/20.500.12000/2621
0286-9640
AN00250774
琉球大学理学部紀要
Bulletin of the College of Science. University of the Ryukyus
73
54
15
eng
open access