PSI - Issue 13

Koji Uenishi et al. / Procedia Structural Integrity 13 (2018) 769–774 Uenishi and Goji / Structural Integrity Procedia 00 (2018) 000–000

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4. Conclusions Dynamic behavior of two-dimensional dry granular slopes that are made of penny-shaped photoelastic polycarbonate particles and subjected to impact loading is observed utilizing a high-speed digital video camera and compared with that of the theoretical and actual slopes under seismic/dynamic excitation. The experimentally recorded stress variations and particle movement inside model granular slopes with the inclination angle of 60 degrees indicate that depending on the profile of energy given by the impact, dynamic response of granular slopes can become significantly different, and typically there are two ways of energy transmission inside the slopes: (i) one-dimensional, unidirectional stress transfer like force chains, leading to mass flow or total collapse; and (ii) broad radiation of energy in the form of waves, with wave-induced separation of slope faces similar to toppling failure. In order to more deeply comprehend the scale effect and diversity in fracture associated with earthquakes and earthquake disaster, more careful experimental and theoretical treatment is required, e.g. concerning the development and networking of single and multiple fractures in granular media. Acknowledgements We would like to sincerely thank the financial support provided by the Japan Society for the Promotion of Science (JSPS) through the “KAKENHI: Grant-in-Aid for Scientific Research (C)” Program (No. 16K06487). References Ashford, S. A., Sitar, N., 1997. Analysis of Topographic Amplification of Inclined Shear Waves in a Steep Coastal Bluff. Bulletin of the Seismological Society of America 87, 692–700. Ashford, S. A., Sitar, N., Lysmer, J., Deng, N., 1997. Topographic Effects on the Seismic Response of Steep Slopes. Bulletin of the Seismological Society of America 87, 701–709. Hancox, G., Perrin, N., Van Dissen, R.: Report on Landslide Reconnaissance Flight on 24 February 2011 Following the Mw 6.3 Christchurch Earthquake of 22 February 2011, GNS Science Immediate Report, LD8 (NZTopo50-BX24)/941-947, 2011. Sitar, N., Clough, G. W., Bachus, R. C.: Behavior of Weakly Cemented Soil Slopes under Static and Seismic Loading, Stanford University, 1980. Uenishi, K., Rice, J. R., 2003. Universal Nucleation Length for Slip-Weakening Rupture Instability under Nonuniform Fault Loading. Journal of Geophysical Research 108(B1), cn:2042, ESE 17-1–17-14. Uenishi, K., Tsuji, K., 2008. The dynamics of collapsing granular columns and its implications in earthquake mechanics, Japan Geoscience Union Meeting. Chiba, Japan, S142-P013. Uenishi, K., Tsuji, K., Doi, S., 2009. Dynamic Deformation and Collapse of Granular Columns. Eos Transactions of AGU (American Geophysical Union) 90(52), Fall Meeting Supplement, T41A-2004. Uenishi, K., 2010a. The Town Effect: Dynamic Interaction between a Group of Structures and Waves in the Ground. Rock Mechanics and Rock Engineering 43, 811–819. Uenishi, K., 2010b. On a Possible Role of Rayleigh Surface Waves in Dynamic Slope Failures. International Journal of Geomechanics 10, 153– 160. Uenishi, K., 2012. Elastodynamic Analysis of Underground Structural Failures Induced by Seismic Body Waves. Journal of Applied Mechanics 79, 031014-1–031014-10. Uenishi, K., Sakurai, S., 2015. Dynamic Tensile Cracking in Slopes Possibly Induced by Rayleigh Surface Waves. Geomechanics and Geoengineering 10, 212–222. Uenishi, K., Goji, T., Debski, W., 2017. Photoelastic study of dynamic stress transfers in granular media, Joint Scientific Assembly of the International Association of Geodesy and the International Association of Seismology and Physics of the Earth’s Interior. Kobe, Japan, S13-6 01. Uenishi, K., 2018. Three-Dimensional Fracture Instability of a Displacement-Weakening Planar Interface under Locally Peaked Nonuniform Loading. Journal of the Mechanics and Physics of Solids 115, 195–207. Yasuda, N., Sumita, I., 2014. Shaking Conditions Required for Flame Structure Formation in a Water-Immersed Granular Medium. Progress in Earth and Planetary Science 1, 13-1–13-11