Design Theory And Method Of GRS-RW Combined With A GRW Or FHR Facing

Geo-synthetic reinforced soil retaining wall(GRS-RW) combined with a GRW facing or FHR facing are two new types of retaining wall. This type of retaining wall is used to get full advantages of GRW and RS-RW as well as to avoid their drawbacks. The application of new system of retaining wall is more and more but its design theory and method are not explicit yet due to the lack of systematic research on the working properties of the new retaining wall system.The design method based on the principle of working strain holds that the backfill is in limit state but the reinforcement is not in its own limit state; while in the traditional design method which is based on the tensile strength of reinforcement, consider both the backfill and the reinforcements are in limit state and also cannot reflect the influence of reinforcement stiffness. As the deformation needed for the tensile failure of reinforcement is much more than that needed for the failure of the backfill, so at the failure mode of GRS-RW, reinforcement exhibit larger deformation rather than facture. Therefore, the design method based on the principle of working strain is more suitable.In this paper, numerical analysis method is done from the stress and strain of both reinforcement and backfill, and the deformation of the retaining wall, the working performance of GRS-RW with GRW facing, and contribution of geo-grids to GRS-RW with a GRW facing, were evaluated. And the analytical method is done for determining the force between GRS-RW with a GRW facing and reinforced soil. Through the comparative analysis of the working performance characteristics between common GRS-RW and GRS-RW with a GRW facing, the analytical methods for the calculation of soil pressure acting on the back of GRW put forward based on the principle of working stress of the reinforcement materials. And an analytical method for determining the force between GRS-RW with a GRW facing and reinforced soil, E is proposed for the first time. By comparative study between theoretical calculation results and numerical analysis results, method1 and method 2 is recommended for determining E is recommended. Moreover, a design approach for the RRR-B construction method of GRS-RW having FHR facing, which has been using in Japan, was provided in detail.And this paper proposed a method for determining the tension in reinforcement of GRS-RW with a GRW facing based on the principle of working strain.