Numerical and Experimental Study on Seismic Behavior of Soil-Nailed Walls to Introduce the Pseudo Static Coefficient Based on Performance Levels

This study, tries to suggest a design method based on displacement using experimental and numerical modeling in soil nailed walls. In this case, dynamic loading characteristics, geometrical characteristics of reinforced soil mass and type of the site are considered to introduce the pseudo static coefficient as a function of seismic performance level and dynamic loading characteristics. For this purpose, the influence of dynamic loading characteristics, reinforcement length, height of reinforced system and type of the site are investigated on seismic behavior of soil nailed wall by numerical analysis. Furthermore, the performance levels of this structure were determined by experimental studies of shaking table tests. The results illustrate that the seismic response of this type of wall is highly dependent to cumulative absolute velocity, maximum acceleration, height and reinforcement length. The results also indicate that the use of coefficients in this study leads to most efficient designs in comparison with other methods which are generally suggested in codes that are usually based on limit-equilibrium concept. The outputs show the over-estimation of equilibrium design methods in comparison with proposed displacement based methods here. The pattern of the observed failure mechanisms included a moving block and a parabolic failure surface with certain inflection point. Also, irrespective of different nail lengths, a range of Δx/H = 0.5 % as a transitional level from quasi-elastic to plastic state and based on starting the development of active wedge failure, a range of Δx/H = 3.75% as a transitional level from plastic to failure state were determined.