Conventionally, seismic stability analyses of GRS structures are conducted within the framework of a pseudo-static approach such as the Mononobe-Okabe method. In this approach; acceleration amplification, the ratio of horizontal acceleration inside earth structures to the input acceleration, is an important parameter when evaluating seismic earth pressure. This study presents a series of dynamic numerical analyses using finite element (FE) and SHAKE analyses to investigate the acceleration amplification within geosynthetics-reinforced soil (GRS) structures under dynamic loading. The objectives of this study were to evaluate the influence of input acceleration and structure height on the acceleration amplification within GRS structures. The numerical results were first compared with dynamic centrifuge test results of two GRS structures with different heights (4 m and 8 m in prototype). Afterward, a parametric study was conducted by varying input accelerations (ag = 0.03 - 0.1 g) and structure heights (H = 4 - 32 m). The numerical results were also used to examine the two prediction methods for acceleration amplification adopted in the design guidelines. This study demonstrated favorable agreement between FE and the centrifuge models in predicting the acceleration amplification profile while an overestimation in the SHAKE analysis results. The FE results indicate the acceleration amplification increases as input acceleration decreases or structure height increases at H > 16 m. The acceleration amplification decreases with the increase of structures height upto 16 m. The prediction method (finite element analyses) for acceleration amplification adopted in the design guidelines (FHWA) cannot describe the trend of acceleration amplification vs. structure height correctly. Additionally, the non-uniform distribution of acceleration amplification profile inside GRS structures was observed in this study. The uniform distribution of acceleration amplification profile, which is assumed in current design guidelines, may underestimate acceleration amplification at the top few layers of GRS structures, resulting in an overestimation of local stability in these areas.

Conventionally, seismic stability analyses of GRS structures are conducted within the framework of a pseudo-static approach such as the Mononobe-Okabe method. In this approach; acceleration amplification, the ratio of horizontal acceleration inside earth structures to the input acceleration, is an important parameter when evaluating seismic earth pressure. This study presents a series of dynamic numerical analyses using finite element (FE) and SHAKE analyses to investigate the acceleration amplification within geosynthetics-reinforced soil (GRS) structures under dynamic loading. The objectives of this study were to evaluate the influence of input acceleration and structure height on the acceleration amplification within GRS structures. The numerical results were first compared with dynamic centrifuge test results of two GRS structures with different heights (4 m and 8 m in prototype). Afterward, a parametric study was conducted by varying input accelerations (ag = 0.03 - 0.1 g) and structure heights (H = 4 - 32 m). The numerical results were also used to examine the two prediction methods for acceleration amplification adopted in the design guidelines. This study demonstrated favorable agreement between FE and the centrifuge models in predicting the acceleration amplification profile while an overestimation in the SHAKE analysis results. The FE results indicate the acceleration amplification increases as input acceleration decreases or structure height increases at H > 16 m. The acceleration amplification decreases with the increase of structures height upto 16 m. The prediction method (finite element analyses) for acceleration amplification adopted in the design guidelines (FHWA) cannot describe the trend of acceleration amplification vs. structure height correctly. Additionally, the non-uniform distribution of acceleration amplification profile inside GRS structures was observed in this study. The uniform distribution of acceleration amplification profile, which is assumed in current design guidelines, may underestimate acceleration amplification at the top few layers of GRS structures, resulting in an overestimation of local stability in these areas.

AASHTO. (2012). American Association of State Highway and Transportation Officials load and resistance factor design bridge design specifications, customary U.S. units.

Ahmed, M. A.-G., & Ronald, F. S. (1979, 12). "Shear moduli and damping factors of earth dam". Journal of the Geotechnical Engineering Division, 105(12), pp. 1405-1426.

Anderson et al. (2008). "Seismic Analysis and Design of Retaining Walls, Buried Structures, Slopes, and Embankments". Transporation research board, Washington, D.C.

Arriaga, F. (2003). "Response of geosynthetic-reinforced structures under working stress and failure conditions". PhD Dissertation, University of Colorado.

Clough, W. R., & Penzien, J. (1995). Dynamics of structures. CA: Computers & Structures.

Elmenshawi, A., Sorour, M., Mufti, A., Jaeger, G. L., & Shrive, N. (2010). "Damping mechanisms and damping ratios in vibrating unreinforced stone masonry". Engineering Structures, 32, pp. 3269-3278.

Erick, Y. K. (2012). "Evaluation of acceleration amplified response and mobilized reinforcement loads within geosynthetic-reinforced structures under dynamic loadings". Master Dissertation, National Taiwan University of Science and Technology, Taiwan.

FHWA. (2001). "Mechanically stabilized earth walls and reinforced soil slopes design and constrcution guidelines". National Highway Institute Federal Highway Administration U.S. Department of Transportation Washington, D.C.
FHWA. (2009). Design and Construction of Mechanically Stabilized Earth Walls and Reinforced Soil Slopes. National Highway Institute Federal Highway Administration U.S. Department of Transportation, Washington, D.C.

Hardin, O. B., & Vincent, D. P. (1972, 6). "Shear modulus and damping in soils: Measurement and parameter effects". Journal of the Soil Mechanics and Foundations Division, 98(6), pp. 603-622.

Huang, C.-C., Horng, J.-C., Chang, W.-J., Chueh, S.-Y., Chiou, J.-S., & Chen, C.-H. (2010, 8). "Dynamic behavior of reinforced slopes: horizontal acceleration response". Geosynthetics International, 17(4), pp. 207-219.

Kramer, L. S. (1996). Geotechnical earthquake engineering. Prentice Hall, Upper Saddle River, N.J.

Krishna, A. M., & Latha, G. M. (2007, 12). "Seismic response of wrap-faced reinforced soil-retaining wall models using shaking table tests". Geosynthetics International, 14(6), pp. 355-364.

Lee, C.-J., Wang, C.-R., Wei, Y.-C., & Hung, W.-Y. (2012, 4). "Evolution of the shear wave velocity during shaking modeled in centrifuge shaking table tests". Bulletin of Earthquake Engineering, 10(2), pp. 401-420.

Ling, I. H., Liu, H., Kaliakin, N. V., & Leshchinsky, D. (2004, 8). "Analying dynamic behavior of geosynthetic-reinforced soil retaining walls". Journal of Engineering Mechanics, 130(8), pp. 991-920.

Liu, h., Wang, X., & Song, E. (2010). "Centrifuge testing of segmental geosynthetic-reinforced soil retaining walls subject to modest seismic loading". GeoFlorida 2010: advances in analysis, modeling & design, (pp. 2992-2998).

ProShake user's manual. (n.d.). Redmond, Washington.

R.B.J. Brinkgreve. (2014). PLAXIS manual. Netherlands.

Richardson, N. G., & Lee, L. K. (1975, 2). "Seismic design of reinforced earth walls". Journal of the Geotechnical Engineering Division, 101(2), pp. 167-188.

Segrestin, P., & Bastick, J. M. (1988, 8). "Seismic design of reinforced earth retaining walls - The contribution of finite element analysis". International Geotechnical Symposium on Theory and Practice of Earth Reinforcement, (pp. 577-582). Fukuoka, Japan.

Spears, R. E., & Jensen, S. R. (2009). "Approach for selection of Rayleigh damping parameters used for time history analysis". ASME Pressure Vessels and Piping Division Conference. Prague, Czech Republic.

Tatsuoka, F., Tateyama, M., Mohri, Y., & Matsushima, K. (2007, 8). "Remedial treatment of soil structures using geosynthetic-reinforcing technology". Geotextiles and Geomembranes, 25(4-5), pp. 204-220.

Verruijt, A. (1994). Soil Dynamic. Papendrecht, Netherlands.

洪汶宜、游騰瑞、邱益增、黃俊鴻、李崇正、邱俊翔、陳正興，『以離心模型試驗探討加勁土堤之動態特性』，第14屆大地工程學術研究討論會，桃園，(2011)。