This study numerically evaluated the combined effects of different controlling factors (i.e., wall height, stresses induced during backfill compaction, reinforcement stiffness, toe conditions, and facing stiffness) on the behavior of geosynthetic-reinforced soil (GRS) walls under working stress conditions. The results were compared with values predicted by different currently used methods. It was shown that toe resistance has a major effect on the prediction capability of those design methods. Parametric analyses have shown that the amount of tension in the reinforcement varies with restraint at the base of the block facing. For free-base conditions with a constant value for reinforcement stiffness, the tension in the reinforcements was the same irrespective of the facing stiffness and the wall height. For the fixed-base conditions, the amount of tension in the reinforcements and horizontal toe load varied as a function of the facing stiffness. Comparing individual measurements of reinforcement tension verified the significant effect that the toe restraint has on the amount of tension mobilized in the reinforcements at the bottom of the wall. The results showed that the amount of tension in the reinforcement is a function of the magnitude of the compaction-induced stress and the reinforcement stiffness. These results indicate that the compaction-induced stress does not significantly affect the magnitude of the horizontal toe load.

Surcharge width and location effects on the behaviour of geosynthetic-reinforced soil walls were experimentally evaluated using the results of three physical models (constructed at the COPPE/UFRJ Geotechnical Laboratory). The walls were well-instrumented in order to monitor the values of the toe load, the reinforcement load, the horizontal facing displacement and the horizontal stress at the back of the block facing. The walls were similar except for the surcharge conditions. At the end of the loading, the toes of the walls were gradually released to verify the influence of the different toe restraints. The results clearly showed the influence of the surcharge width and location on the wall behaviour, and also showed that the surcharge location and toe release can change the position of the maximum mobilised tension along the reinforcement. Furthermore, the location of the surcharge may affect the shape of the facing displacement profile.

Purpose: Self‐compacting concrete (SCC) offers several economic and technical benefits; the use of steel fibers extends its possibilities. Steel fibers bridge cracks, retard their propagation, and improve several characteristics and properties of the SCC. The purpose of this paper is to investigate the effects of type and volume fraction of steel fiber on the compressive strength, split tensile strength, flexural strength and modulus of elasticity of steel fiber reinforced self‐compacting concrete (SFRSCC).Design/methodology/approach: For this purpose, Micro wire and Wave type steel fibers with l/d ratios of 50 were used. Three different fiber volumes were added to concrete mixes at 0.5, 0.75 and 1 per cent by volume of SCC. Six different SFRSCC mixes were prepared. After 28 days of curing, compressive, split and flexural strength and modulus of elasticity were determined.Findings: It was found that, inclusion of steel fibers significantly affect the split tensile and flexural strength of SCC accordance with type and v_f. Besides, mathematical expressions were developed to estimate the flexural, modulus of elasticity and split tensile strength of SFRSCCs regarding of compressive strength.Originality/value: It was found that inclusion of steel fibers significantly affected the split tensile and flexural strength of SCC accordance with type and f v.

This study numerically evaluates the influence of excavation execution procedures in combination with the nail stiffness, facing stiffness and inclination, surcharge width and position and excavation near to the bottom on the behaviour of nailed-soil structures under working stress conditions. The numerical analyses are carried out using the two-dimensional finite-element program Plaxis 2D 2015. Data from a full-scale physical model of soil nailing constructed by the French national research project, Clouterre, is first used for the validation of the analyses. In the parametric study, two different excavation execution procedures are investigated. The first procedure represents the execution of small-width incremental excavation, starting from one side of the wall and progressing along the same level to the other side. In the second procedure, which can occur in the field, each level is fully excavated, and then nail installation and shotcreting are performed. The results show the effect of each execution procedure, in combination with the other factors mentioned, on the behaviour of the soil-nailing structure and indicate the first procedure to be the optimum construction process.