Reliability-Bsed Optimization Design of Geosynthetic Reinforced Road Embankment

摘要

Road embankment is normally a large structure, the construction of which requires for large amounts of soil normally of good quality. In order to limit costs, the utilization of geosynthetic in road embankment allows for construction of steep slopes up to 80 - 85 degrees, which can save vast amounts of fill soil and land take compared to a traditional unreinforced one. It then requires for a stability analysis regarding the geosynthetic reinforced slope, which is highly depending on the selection and properties of geosynthetic including the tensile strength, transfer efficiency, length and number of geosynthetic layers placed in embankment, etc. To minimize costs, the optimization design is necessary to select an optimal combination of those design parameters. In this study, the reliability-based optimization (RBO) will be implemented on the basis of reliability-based probabilistic slope stability analysis considering the variability of soil properties. RBO intends to minimize the cost involved in geosynthetic reinforced road embankment design while satisfying all technical requirements. The limit equilibrium method will be embedded to compute the factor of safety (FS), meanwhile, the MPP-based first-order reliability method (FORM) will be performed to determine the probability of failure (pf). The cost is assumed as a function of design parameters: the number of geosynthetic layers, embedded length, and the tensile strength of geosynthetic. Coupling with the reliability assessment and some other technical constraints, the combination of design parameters can be optimized for a minimum cost. 7