加勁擋土牆之設計一般以側向土壓力法進行內部穩定檢核，並以極限平衡法軟體進行邊坡穩定分析，以檢核整體穩定性。然而若能同時使用極限平衡法進行內部與整體穩定分析能有利於設計上之便利性以及推廣加勁擋土牆工法。
有鑑於此，本研究將探討利用邊坡穩定軟體分析，進行加勁擋土牆的內部穩定分析之適用性，本論文說明如何利用極限平衡法預測在加勁擋土牆設計上加勁材所需之強度與長度，並透過三個實際案例進行驗證與比較。研究結果顯示，在加勁材所需之張力強度上，極限平衡法所預測之值較接近於量測值，為較佳與較經濟的方法，而使用側向土壓力法進行預測有高估的趨勢，在設計上過於保守。在所需之長度上使用側向土壓力法及極限平衡法都有效的縮短了加勁材所需之長度，且同時滿足設計上所要求的安全係數。

In general, geosynthetic-reinforced soil (GRS) wall designs examine the internal stability by lateral earth pressure method, and use limit equilibrium analysis to check overall stability of GRS wall. However, if internal and overall stability analysis can be simultaneously conducted using limit equilibrium method, it is beneficial to provide the convenience of wall design and to promote the GRS walls application.

This study used slope stability software to investigate the adaptability of GRS wall internal stability analysis. This thesis described the method that how to predict the required length and strength of reinforcement by limit equilibrium analysis and conducted the verification and comparison through three actual cases.

The results showed that the value predicted by limit equilibrium method is closer to the measurement in required tensile strength of reinforcement than lateral earth pressure method, which is a more economical design. And the value predicted by lateral earth pressure method is likely to overestimate which is conservative for design. It is effective to shorten the required length of reinforcement and fulfil the required factor of safety by lateral earth pressure method and limit equilibrium method.

AASHTO. (2002). “Standard specifications for highway bridges”. Vol. 17th Edition, Washington, DC: American Association of State Highway and Transportation Officials.

Allen, T.M. and Bathurst, R.J. (2003). “Prediction of reinforcement loads in reinforced soil walls”. Report No. WA-RD 522.2, Washington State Department of Transportation.

Allen, T.M., and Bathurst, R.J. (2002). “Soil reinforcement loads in geosynthetic walls at working stress conditions”. Geosynthetics International, 9(5-6), 525-566.

Bathurst, R.J., Vlachopoulos N., Walters, D.L., Burgess, P.G., and Allen, T.M. (2006). “The influence of facing stiffness on the performance of two geosynthetic reinforced soil retaining walls”. Canadian Geotechnical Journal, 43(12), 1225-1237.

Bathurst, R.J. (1990). “Instrumentation of geogrid-reinforced soil walls”. Transportation Research Board, 1277, 102-111.

Duncan, J.M. and Wright, S.G. “Soil strength and slope stability”. John Wiley and Sons, Inc., Hoboken, New Jersey

FHWA. (2001). “Mechanically stabilized earth walls and reinforced soil slopes design and construction guidelines”. National Highway Insitute, Federal highway administration, U.S. Department of Transportation, Washingtom, D.C.

Leshchinsky, D. (2010) “Geosynthetic reinforced walls and steep slopes: is it magic”. Geosynthetics Magazine, 28(3), 16-24.

Leshchinsky, D. (2009) “On Global Equilibrium in Design of Geosynthetic Reinforced Wall”. Journal of Geotechnical and Geoenvironmental Engineering, ASCE, 135(3), 309-315.

Yang, K.H, Zornberg, J.G., Hung, W.Y. & Lawson, C.R. (2011). “Location of failure plane and design considerations for narrow geosynthetic reinforced soil wall systems”, Journal of GeoEngineering, 6(1), 27-40.

Yang, K.H, Utomo P. & Liu T.L. (2013). “Evaluation of force-equilibrium and deformation-based design approaches for predicting reinforcement loads within geosynthetic-reinforced soil structures”. Journal of GeoEngineering, 8(2), 41-54.

Zornberg, J.G., Sitar, N., and Mitchell, J.K. (1998) “Limit Equilibrium as Basis for Design of Geosynthetic Reinforced Slopes.” Journal of Geotechnical and Geoenvironmental Engineering, ASCE, 124(8), 684-698.