[1]FU Ping,ZHANG Xinhui,YIN Jianmin,et al.Numerical Simulation of the Tectonic Deformation Features and Stress Fields Evolution of the Middle Segment of Longmenshan Fault Zone and Its Adjacent Areas[J].Journal of Seismological Research,2020,43(01):28-36.
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Journal of Seismological Research[ISSN 1000-0666/CN 53-1062/P] Volume:
43
Number of periods:
2020 01
Page number:
28-36
Column:
Public date:
2020-01-30
- Title:
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Numerical Simulation of the Tectonic Deformation Features and Stress Fields Evolution of the Middle Segment of Longmenshan Fault Zone and Its Adjacent Areas
- Author(s):
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FU Ping; ZHANG Xinhui; YIN Jianmin; HAN Xiaoyu; ZHOU Chunhua
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(Key Laboratory of Geotechnical Mechanics and Engineering of the Ministry of Water Resources,Changjiang River Scientific Research Institute,Wuhan 430010,Hubei,China)
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- Keywords:
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Longmenshan fault zone; tectonic movement; deformation rate; crustal stress; finite element modeling
- CLC:
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P315.725
- DOI:
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- Abstract:
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Based on the regional tectonic characteristics of the middle segment of Longmenshan fault zone and its adjacent areas,a two-dimensional contact finite element model is established to simulate the evolution of displacement and stress fields during long term tectonic movement.The differences of wave velocity and tectonic movement rate between the deep and shallow crust are taken into consideration.The numerical results indicate that the:①Thrust fault slip rates of Wenchuan-Maoxian,Yingxiu-Beichuan and Guanxian-Anxian fault are basically consistent with the observed data,and Yingxiu-Beichuan fault has more stronger thrust property.The Bayan Har block and the fault zone experience overall uplift and shortening,while the Sichuan basin remains relatively stable.②The ratios of maximum and minimum principal stress near faults decrease as the depth increases,and broadly conform with the in-situ stress measurements.Furthermore,the simulated principal stress directions and inclination are close to that inversed by focal mechanism solutions.③The tectonic stress field of Longmenshan fault zone presents a staged evolution of low state stability-stress accumulation-critical state stability,which is correspond with the seismic activity feature of stress accumulation-earthquake occurrence-stress reaccumulation.In addition,we suggest that seismic risk assessment needs the comprehensive analyses of the deep geodynamic process and regional stress states,for the slip rates of the active faults obtained from near-surface survey and GPS observations are much limited.