2001 Fiscal Year Final Research Report Summary
Faulting process and strong ground motion predicted from crustal deformation
| Project/Area Number |
12650558
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Building structures/materials
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| Research Institution | Tohoku University |
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Principal Investigator |
KURITA Satoshi Tohoku Univ., Graduate School of Eng., Assoc. Prof., 大学院・工学研究科, 助教授 (90195553)
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| Project Period (FY) |
2000 – 2001
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| Keywords | Faulting process / Fault model / Friction element / Crustal deformation / Stopping of frictional displacement / Stick-slip friction |
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| Research Abstract |
1) Crustal deformation around the Nagamachi-Rifu faults
The horizontal crustal deformation around the Nagamachi-Rifu faults was investigated from the records observed by GPS earth observation network of the Geographical Survey Institute. The strain rates of the crustal deformation were estimated by taking a triangular composed of three GPS observation points as a triangular element of finite element method and using the technique of strain calculation in finite element method. The magnitude of the strain rate varied spatially, but the major principal directions of the rates were almost perpendicular to the strike of the faults. This result indicates that the Nagamachi-Rifu faults are thrust faulting.
2) Simulation of fault rupture of the Nagamachi-Rifu faults
A method for evaluating the fault parameters such as breakdown shear stress, breakdown stress drop, and critical slip displacement on fault surface was developed theoretically by using empirical equation of the parameters obtained fr
… More
om breakdown experiments of rocks and taking the variations of temperature and initial stress in crust into account. Using the method, the finite element model of the Nagamachi-rifu faults was build. We performed the rupture simulations of the faults by applying the crustal deformation to the lateral boundaries of the finite element model as prescribed displacement. The numerical errors were observed in the time history of acceleration on the ground obtained from the simulation. The errors seemed to be caused by the numerical problem that the joint elements adopted as fault model is incapable of simulating stick phase after cease of sliding.
3) Stick phase after cease of fault sliding
To overcome the above numerical problem, a numerical technique was developed on the base of block-slider model. The technique permit to simulate the stickmode. In order to validate the proposed numerical technique, the numerical results were compared with the exact solutions of block-slidermodel for harmonic steady state motion and the results obtained by the vibration experiments of block-slider specimen. The proposed method simulated the exact solutions and the experimental results. Less
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Research Products
(8 results)
