Finite Element Study on Lateral Bearing Capacity and Failure Mode of Geosynthetic-Reinforced Soil Barriers

• Main Authors: Yi-Shou Chen, 陳毅修
• Other Authors: Kuo-Hsin, Yang
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/99756263332074700405

碩士 === 國立臺灣科技大學 === 營建工程系 === 102 === Geosynthetic-reinforced soil (GRS) structures are often used to carry vertical surcharges. Recently, GRS structures have been applied as barriers to resist lateral force from natural disasters such as flood, tsunami, rock fall, debris flow, and avalanche. In design guideline, the stability of such structures is often evaluated by conducting the conventional external stability analyses assuming the reinforced soil mass as a rigid body. However, the assumption of rigid body contradicts with the flexible nature of reinforced soil. In this study, finite element (FE) models of back-to-back GRS walls were developed to investigate the failure mode and lateral bearing capacity of GRS barriers subjected to lateral loadings. The FE result showed GRS barriers generated bending deformation when subjected to lateral force. As a result, the vertical stress at the side of wall subjected to lateral force decreased due to the bending deformation induced tension stress. On the other hand, the vertical stress at the opposite side increased because of the bending deformation induced compression stress. The failure mode depended on the aspect ratio of GRS barriers L/H (ratio of wall width to wall height). When 0.5 < L/H < 1, the GRS barriers subjected to lateral loading failed internally. Due to the development of bending stress, the GRS barriers failed due to the internal sliding along the soil-reinforcement interface at the side subjected to the lateral force and meanwhile the active failure of reinforced soil wedge at the opposite side. When 1.0 < L/H < 3.0, sliding failure at the bottom of GRS barriers occurred. When L/H > 3.0, the passive soil failure occurred within GRS barriers at the side subjected to the lateral force. The parametric study results indicated the major factor to affect the ultimate lateral bearing capacity was the aspect ratio of GRS barriers. As L/H increases, the lateral bearing capacity of GRS structures increased from approximately twice of active lateral earth pressure at L/H = 0.5 to the passive lateral earth pressure at L/H = 3.0.