Secondary reinforcement effect on the value and location of maximum reinforcement load

Abstract

This paper numerically evaluates the effect of secondary reinforcement on the value and location of the maximum reinforcement load along the primary reinforcement layers (Tmax) in geosynthetic-reinforced soil (GRS) walls under working stress conditions. Data from three instrumented sections of a well-instrumented GRS wall were used for model validation. A parametric study was carried out considering different controlling factors (i.e. the vertical reinforcement spacing, facing type and secondary reinforcement stiffness and length). The results show that for a constant relative soil-reinforcement stiffness index, the variation of the vertical reinforcement spacing and stiffness may not affect the location and normalised value of Tmax. In general, for the conventionally used type of reinforcement, the secondary reinforcement inclusion reduces Tmax to values lower than those corresponding to the active condition (Ka). For a given facing type, the combined effect of the secondary reinforcement length and stiffness is the main factor that controls the Tmax location. In general, increasing the secondary reinforcement stiffness and length moves the location of Tmax from the back of the facing to a distance corresponding to the length of the secondary reinforcement layers. In addition, for this condition, a flexible face model performs similarly to a block face model.