Original Paper(Vol.54 No.11 pp.1153-1158)

Mechanism of Reinforcement and Restraint Effect for Soil Nailing Method in Cut Slop

Tatsuaki NISHIGATA, Kazuhiko NISHIDA and Shinichi INABA

Abstract:Conventional design method for soil nailing is based on the effects of tensile force developed in reinforcement installed in cut slope. As the tensile force is affected by the deformation of reinforced slope, the approach of the design method should be on the basis of the allowable deformation. On the other hand, it is said that the restraint effect in reinforced zone is more effective for reinforced slope stability under conditions of small allowable deformation. However, even the definition of the restraint effect for bar of reinforcement is still not clear. In this study, the reinforcement mechanism of restraint effect is investigated by distinct element method firstly, and secondly the effect of the interval of reinforcements on the development of restraint effect is examined by finite element method. Finally, it concludes that the design method of considering the restraint effect is effective to the reinforcement of high priority structure as a cut slope in important road system.

Key Words:Key words: Soil nailing, Cut slope, Restraint effect, Distinct element method, Finite element method, Allowable deformation