Finite element method analysis of support system of soil nailing

Soil nailing is one of the widely used methods of site improvement to slope stability in all over the world. Nowadays, local and global stability analyses are conducted in the design of soil nails. Soil slope stability analysis based on the limit equilibrium methods are used in these analyses. In this method, displacements and deformations of the soil cannot be calculated. Therefore generally, finite element, finite difference method is used or any other actions are taken to numerical analysis in the calculation of the displacement of the excavation with soil nailing walls and in the surrounding structures. Nonlinear behavior, excavation and construction steps in the structural elements ground / structure interaction is taken into account in designs which are made with this numerical analysis. These designs can be safer and more economical compared to other analysis methods. However, stability analyses with numerical analysis lack proven testable results. Hence there is a need for comparison with field observations to promote the use of numerical analysis in the soil nail designs which have different ground conditions and geometry. Starting with the need, numerical analysis of soil nailed wall is compared with field observations in this thesis. In this context, numerical analysis of the Clouterre 1991 Project (France) which investigates the stability of the 1: 1 scale soil nail wall is compared with field measurements. Analysis of two dimensional stress deformations carried out using commercial software Plaxis. Soil nails elements are modeled with geogrid (drawing board) , plate, embedded beam rows which are embedded in the software. Then analysis results are compared with the measurements obtained in the experiments. Safety factor obtained in these analyses which includes stability verification is compared with the results based on the limit equilibrium slice method. Based on the limit equilibrium classical slope stability analyzes are conducted with TALREN which is a software developed by Clouterre projects. As a result of these analyzes, field measurements of displacement are close with analyzed ones. It is seen that calculated normal and friction forces of geogrid, plate, embedded beam rows which are used for nails in PLAXİS 2D, is consistent with each other and field measurements. It is also observed that values in the embedded beam rows are closer to in the field measurements. On the other hand, security numbers obtained for each different soil nail element in the finite element method of stability analysis is consistent. It is also consistent with those made by Simplified Bishop.