INVESTIGATION OF ACTIVE FAILURE SURFACES OCCURRING BEHIND THE T TYPE CANTILEVER RETAINING WALL.

Retaining structures are designed considering lateral earth thrust or pressure distribution acting on the wall. Determination of failure surfaces play vital role in active lateral earth pressure calculations acting on retaining structures. As failure surface pattern varies based on heel length, there is particular importance of heel length of T type cantilever retaining walls on determination of earth thrust. Lateral earth calculations are performed for two different cases, namely short heel or long heel, based on the intersection of T type cantilever wall and failure surface. In this study, the effect of heel length on an active failure mechanism was examined with numerical simulation based on finite element method (FEM). The results of the numerical analyses were compared with the results of small-scale model tests and an analytical method. In comparison, the inclination angle of active failure surfaces was taken into account. An earth thrust maximization code suggested in the literature was used to determine failure surface inclination angles analytically. In order to determine failure inclination experimentally, results of small scale tests were used. In the tests, failure surfaces were determined using particle image velocimetry technique (PIV). Numerical analysis was performed using commercially available finite element program Plaxis 2D. The same material properties are used in all numerical models. As a result of the study compatible results with literature was obtained. The effects of heel length, foundation thickness, density parameters on failure surface inclination angles were examined numerically. Due to friction between wall and backfill differences between failure surface inclination angles were determined. Increased heel length caused to decrease of failure surface inclination. However, it was seen that long heel and short heel cases could not be recognized clearly considering the results of numerical analyses. [ABSTRACT FROM AUTHOR]