Hybrid experimental and numerical approach for assessment of non-linear dynamic behavior of soil-nailed retaining walls

Seismic Performance-based design demands reliable means for profound understanding of inelastic and nonlinear dynamic behavior of civil structures. In this study, a hybrid experimental and numerical approach for seismic assessment of soil-nailed structures is introduced which incorporates simple static loading of a small-scale physical model and non-linear dynamic analysis of a two degree-of-freedom (2 DOF) system. A vertical loading pattern was applied on a small-scale modeling test behind a soil-reinforced block at the surface to mobilize extra lateral pressure on the reinforced soil zone. Two non-linear force-displacement relations obtained from the lateral pressure and facing displacement values of the physical test have been denoted as capacity curves and employed as the non-linear stiffness of the 2 DOF springs. The capacity curves obtained from this approach inherently take into account the complexities of soil, nail, soil-nail-facing interactions and geometrical nonlinearities. The results of dynamic analysis from the 2 DOF model are presented in terms of bottom and top displacements as the direct performance of the structure under seismic excitation. A soil-nailed wall was tested under different input motions on a shaking table and the results were compared to assess the accuracy of the approach and identify the performance levels of soil-nailed structures.