Designing geosynthetic reinforced slopes with safety maps

摘要

The design objective of geosynthetic reinforced earth structures is to determine safe and economical length and strength of reinforcement. This paper presents an efficient computerized approach to determine the optimal strength and length of geosynthetic reinforcement using limit equilibrium analysis. The analysis considers the interaction of soil-geosynthetic and the interaction among reinforcement layers. The end result ensures sufficient length and strength of reinforcement so as to satisfy a prescribed minimum factor of safety. As commonly done in slope stability analysis, this factor of safety is applied on the shear strength of the soils comprising the slope. The analysis also considers the required strength of the connection to facing units. The approach considers the existing strength of reinforcement based on layout, pullout resistance at the front and rear of each layer, and long-term geosynthetic strength. While the analysis itself is not novel and can be used with any method for which the failure geometry is well defined, linking it to a color-coded safety map makes the design process efficient and objective leading to optimized layout and strength of reinforcement. The safety map provides a diagnostic tool on the state of stability of a reinforced slope without the lengthy trial-and-error tedium usually associated with such a process.