Seismic fault model for calculating exactly the dynamic motion in the stick phase and generation of short-period seismic motion
| Project/Area Number |
15560483
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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 University, Graduate School of Engineering, Associate Professor, 大学院・工学研究科, 助教授 (90195553)
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| Project Period (FY) |
2003 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥3,800,000 (Direct Cost: ¥3,800,000)
Fiscal Year 2004: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2003: ¥2,700,000 (Direct Cost: ¥2,700,000)
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| Keywords | Fault model / Friction / Seismic motion / Stopping phase / Stick phase / Finite element method |
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| Research Abstract |
This research project proposed a numerical method for calculating the enact motions in the stopping phase on fault planes that the hitherto developed methods are incapable of simulating. The method was applied to the simulation of the observed motions obtained by a frictional experiment.
First, the review of the analytical methods for the dynamic motions in the slippage and stopping phases on fault planes was performed The review clarified the numerical problems in analyzing the dynamic frictional behavior of fault planes : 1.the number of degree of freedom of the nodes on a fault plane is different between the stopping phase and sliding phase, 2.artificial short-period seismic motions are produced by the inaccuracy of the estimated time when a sliding will stop. 3.the numerical accuracy of dynamic motions in bi-directional sliding is worse than that in one-directional sliding. Secondly, in order to solve problem 1.a novel idea was found out. The idea is that the motions of the two body contacted in the stick phase are the same as those of the two body in the sliding phase which are slipping at the slip velocity of zero. From the idea, the identical equation of motion for the stick and the sliding phases were derived. For solving the problem 2.the definition was introduced that the slippage velocity and acceleration reach to zero simultaneously when the slippage ceases. By applying the definition to the Newmark's integration method, a numerical method to calculate the exact time when the slippage ceases without iteration was proposed. Finally, the accuracy of the proposed numerical methods were validated by simulating a sliding experiment that had been performed for sliding bearings for base isolated buildings. This experimental data were adapted since there was no experimental data seismic fault slippage including the motions in the stoppingphase.
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Report
(3 results)
Research Products
(3 results)
