單速旋剪摩擦試驗在過去幾十年中成功地被用來探討斷層力學與大型山崩滑移。近期研究顯示，集集地震誘發之草嶺山崩在快速滑動前，藉由Newmark分析可以觀察到山崩塊體在觸發階段時有加速與減速的運動，此一結果顯示在加減速條件下，較能符合地震及山崩之滑動過程，因此以加減速條件研究滑動面摩擦特性有其必要性。本研究利用根據單速旋剪摩擦試驗所建立之速度與位移相依摩擦律，模擬在加速減速滑移過程中斷層泥摩擦係數的改變，並與前人研究比較，結果發現在變速度實驗過程時，在滑移速度降至零時，剪切材料之強度會回復至最大值，與實際震盪速度試驗結果不符。因此本研究進一步利用純高嶺土進行單速與加、減速旋剪試驗，並根據試驗結果，建立高嶺土之速度-位移相依摩擦律，本研究建議之摩擦律納入了加、減速行為、最大速度，以符合加減速試驗所觀察到的摩擦係數回復值隨頻率增加而減小的現象，並可進一步應用於地震斷層動力學或地震誘發山崩之觸發機制。

Rotary-shear friction experiments have been successfully used to study the earthquake dynamics and catastrophic landslides in the past two decades. In addition, the oscillating movement was observed in Tsaoling landslide by Newmark Analysis. Recent studies indicated that the friction behaviors of fault gouge materials under oscillatory shear are different from those under constant shear. Previous experimental results revealed that the accelerating and decelerating motion caused weakening and strengthening, while undergoing overall slip-weakening. In this study, we try to approximate the temporal variation of friction coefficient during accelerating/decelerating slip based on a velocity-displacement dependent friction law derived from constant rotary shear tests. The approximated results show a full strength recovery behavior when the slip velocity reduced to zero, which cannot depict the experimental results. Therefore, we conducted a series of the oscillatory velocity experiments with pure kaolinite to establish a new velocity-displacement dependent friction law. The mechanisms behind the differences of friction behaviors between the oscillatory and constant rotary shear tests will be explored.

American Society for Testing and Materials, 2014. Standard test methods for laboratory determination of water (moisture) content of soil and rock by mass, ASTM D2216-10.
American Society for Testing and Materials, 2014. Standard test method for particle-size analysis of soils, ASTM D422-63.
American Society for Testing and Materials, 2014. Standard test methods for specific gravity of soil solids by water pycnometer, ASTM D854-13.
American Society for Testing and Materials, 2014. Standard test method for liquid limit, plastic limit, and plasticity index of soils, ASTM D4318-10.
Aparicio, P., Galán, E., Valdrè, G., and Moro, D., 2009. Effect of pressure on kaolinite nanomorphology under wet and dry conditions correlation with other kaolinite properties, Applied Clay Science, Vol. 46, pp. 202-208.
Bhat, D. R., Bhandary, N., and Yatabe, R., 2013. Effect of shearing rate on residual strength of kaolin clay, The Electronic Journal of Geotechnical Engineering, Vol. 18(G), pp. 1387-1396.
Brace, W. F., and Byerlee, J. D., 1966. Stick-slip as a mechanism for earthquakes, Science, Vol. 153, pp. 990-992.
Brace, W. F., and Byerlee, J. D., 1970. California earthquakes: Why only shallow focus?, Science, Vol. 168, pp. 1573-1575.
Brantut, N., Schubnel, A., Rouzaud, J. N., Brunet, F., and Shimamoto, T., 2008. High‐velocity frictional properties of a clay‐bearing fault gouge and implications for earthquake mechanics, Journal of Geophysical Research: Solid Earth, Vol. 113, B10401.
Bro, A. D., Stewart, J. P., and Pradel, D., 2013. Estimating undrained strength of clays from direct shear testing at fast displacement rates, Geocongress 2013--Stability and Performance of Slopes and Embankments III, Vol. 231(5).
Byerlee, J. D., 1967. Frictional characteristics of granite under high confining pressure, Journal of Geophysical Research, Vol. 72, pp. 3639-3648.
Byerlee, J., 1978. Friction of rocks, Pure and Applied Geophysics, Vol. 116, pp. 615-626.
Chen, C. Y., Lan, G. S., and Tuan, W. H., 2000. Microstructural evolution of mullite during the sintering of kaolin powder compacts, Ceramics International, Vol. 26(7), pp. 715-720.
Dieterich, J. H., 1972. Time-dependent friction in rocks, Journal of Geophysical Research, Vol. 77, pp. 3690-3697.
Dieterich, J. H., 1979. Modeling of rock friction: 1. Experimental results and constitutive equations, Journal of Geophysical Research, Vol. 84, pp. 2161-2168.
Dieterich, J. H., 1981. Constitutive properties of faults with simulated gouge, Mechanical behavior of crustal rocks: the Handin volume, pp. 103-120.
Di Toro, G., Han, R., Hirose, T., De Paola, N., Nielsen, S., Mizoguchi, K., Ferri, F., Cocco, M., and Shimamoto, T., 2011. Fault lubrication during earthquakes, Nature, Vol. 471, pp. 494-498.
Ferri, F., Di Toro, G., Hirose, T., and Shimamoto, T., 2010. Evidence of thermal pressurization in high-velocity friction experiments on smectite-rich gouges, Terra Nova, Vol. 22(5), pp. 347-353.
Ferri, F., Di Toro, G., Hirose, T., Han, R., Noda, H., Shimamoto, T., Quaresimin, M., and de Rossi, N., 2011. Low-to high-velocity frictional properties of the clay-rich gouges from the slipping zone of the 1963 Vaiont slide, northern Italy, Journal of Geophysical Research: Solid Earth, Vol. 116, B09208.
Hirose, T., and Shimamoto, T., 2005. Growth of molten zone as a mechanism of slip weakening of simulated faults in gabbro during frictional melting, Journal of Geophysical Research: Solid Earth, Vol. 110, B05202, doi:10.1029/2004JB003207.
Hirose, T., and Shimamoto, T., 2005. Slip-weakening distance of faults during frictional melting as inferred from experimental and natural pseudotachylytes, Bulletin of the Seismological Society of America, Vol. 95, pp. 1666-1673.
Ho, C. S., 1990. General Geology, the third edition, Wu-Nan Culture Enterprise, Taipei.
Li, Y. R., Wen, B. P., Aydin, A., and Ju, N. P., 2013. Ring shear tests on slip zone soils of three giant landslides in the three gorges project area, Engineering Geology, Vol. 154, pp. 106-115.
Lin, M. L., Jeng, F. S., Ueng, T. S., and Hung, J. J., 2000. New developments assessing mechanical properties of fault gouges, Sino-Geotechnics, No. 79, pp. 91-106.
Marone, C., 1998. Laboratory-derived friction laws and their application to seismic faulting, Annual Review of Earth and Planetary Sciences, Vol. 26(1), pp. 643-696.
Mizoguchi, K., Hirose, T., Shimamoto, T., and Fukuyama, E., 2007. Reconstruction of seismic faulting by high-velocity friction experiments: an example of the 1995 Kobe earthquake, Geophysical Research Letters, Vol. 34, L01308, doi:10.1029/2006GL027931.
Miyamoto, Y., Shimamoto, T., Togo, T., and Dong, J. J., 2009. Dynamic weakening of shale and bedding-parallel fault gouge as a possible mechanism for Tsaoling landslide induced by 1999 Chi-Chi earthquake, In Proceedings of the Next Generation of Research on Earthquake-Induced Landslides: An International Conference in Commemoration of 10th Anniversary of the Chi-Chi Earthquake, pp. 398-401.
Ni, J., Indraratna, B., Geng, X. Y., and Rujikiatkamjorn, C., 2012. The effect of the strain rate on soft soil behaviour under cyclic loading, In: Proceedings of the 11th Australia New Zealand conference on geomechanics: ground engineering in a changing world, pp. 1340-1345.
Ölmez, M. S., 2008. Shear strength behaviour of sand-clay mixtures, Middle east technical university, PhD thesis.
Rice, J. R., 1983. Constitutive relations for fault slip and earthquake instabilities, Pure and Applied Geophysics, Vol. 121(3), pp. 443-475.
Rice, J. R., and Ruina, A. L., 1983. Stability of steady frictional slipping”, Journal of applied mechanics, Vol. 50(2), pp. 343-349.
Ruina, A., 1983. Slip instability and state variable friction laws, Journal of Geophysical Research, Vol. 88, pp. 10359-10370.
Sawai, M., Shimamoto, T., and Togo, T., 2012. Reduction in BET surface area of Nojima fault gouge with seismic slip and its implication for the fracture energy of earthquakes, Journal of Structural Geology, Vol. 38, pp. 117-138.
Scholz, C. H., Molnar, P., and Johnson, T., 1972. Detailed studies of frictional sliding of granite and implications for the earthquake mechanism, Journal of Geophysical Research, Vol. 77, pp. 6392-406.
Sengupya, P., Saikia, P. C., and Borthakur, P. C., 2008. SEM-EDX characterization of an iron-rich kaolinite clay, Journal of Scientific and Industrial Reasearch, Vol. 67, pp. 812-818.
Shimamoto, T., and Logan, J. M., 1981. Effects of simulated clay gouges on the sliding behavior of Tennessee sandstone, Tectonophysics, Vol .75, pp. 243-255.
Shimamoto, T., and Tsutsumi, A., 1994. A new rotary-shear high-speed frictional testing machine: its basic design and scope of research, Journal of the Tectonic Research Group of Japan, Vol. 39, pp. 65-78.
Shimamoto, T., and Togo, T., 2012. Earthquakes in the Lab, Geophysics, Vol. 338, pp. 54-55.
Skempton, A. W., 1964. Long-term stability of clay slopes, Geotechnique, Vol. 14, pp. 77-102.
Sone, T., and Shimamoto, T., 2009. Frictional resistance of faults during accelerating and decelerating slip, Nature Geoscience, Vol. 2, pp. 705-708.
Suzuki, M., Yamamoto, T., Tanikawa, K., Fukuda, J., and Hisanaga, K., 2002. Variation in residual strength of clay with shearing speed, Memoirs of the Faculty of Engineering, Yamaguchi University, Vol. 50, pp. 45-49.
Togo, T., Shimamoto, T., Ma, S., and Hirose, T., 2011. High-velocity frictional behavior of Longmenshan fault gouge from Hongkou outcrop and its implications for dynamic weakening of fault during the 2008 Wenchuan earthquake, Earthquake Science, Vol. 24(3), pp. 267-281.
Togo, T., and Shimamoto, T., 2012. Energy partition for grain crushing in quartz gouge during subseismic to seismic fault motion: an experimental study, Journal of Structural Geology, Vol. 38, pp. 139-155.
Togo, T., Shimamoto, T., Dong, J. J., Lee, C. T., and Yang, C. M., 2014. Triggering and runaway processes of catastrophic Tsaoling landslides induced by the 1999 Taiwan Chi-Chi earthquake, as revealed by high-velocity friction experiments, Geophysical Research Letters, Vol. 41(6), pp. 1907-1915.
Tsao, C. C., 2014. The geometric characteristics and initiation mechanisms of the earthquake-triggered Daguanbao landslide, National Central University, Master thesis.
Tsutsumi, A., and Shimamoto, T., 1997. High-velocity frictional properties of gabbro, Geophysical Research Letters, Vol. 24(6), pp. 699-702.
White, W. A., 1949. Atterberg plastic limits of clay minerals, American Mineralogist, Vol. 34, pp. 508-512.
Yang, C. M., Yu, W. L., Dong, J. J., Kuo, C. Y., Shimamoto, T., Lee, C. T., Togo, T., and Miyamoto, Y., 2014. Initiation, movement, and run-out of the giant Tsaoling landslide — What can we learn from a simple rigid block model and a velocity–displacement dependent friction law?, Engineering Geology, Vol. 182, pp. 158-181.
Yano, K., Shimamoto, T., Oohashi, K., Dong, J. J., and Lee, C. T., 2009. Ultra low friction of shale and clayey fault gouge at high velocities: implication for Jiufengershan landslide induced by 1999 Chi-Chi earthquake, In Proceedings of the Next Generation of Research on Earthquake-induced Landslides: An International Conference in Commemoration of 10th Anniversary of the Chi-Chi Earthquake, pp. 402-406.
Yao, L., Ma, S., Shimamoto, T., and Togo, T., 2013. Structures and high-velocity frictional properties of the Pingxi fault zone in the Longmenshan fault system, Sichuan, China, activated during the 2008 Wenchuan earthquake, Tectonophysics, Vol. 599, pp. 135-156.
Yao, L., Shimamoto, T., Ma, S., Han, R., and Mizoguchi, K., 2013. Rapid postseismic strength recovery of Pingxi fault gouge from the Longmenshan fault system: Experiments and implications for the mechanisms of high‐velocity weakening of faults, Journal of Geophysical Research: Solid Earth, Vol. 118(8), pp. 4547-4563.
Zhang, L., and He, C., 2013. Frictional properties of natural gouges from Longmenshan fault zone ruptured during the Wenchuan Mw7.9 earthquake, Tectonophysics, Vol. 594, pp. 149-164.