No abstract

No abstract

No abstract

The effect of preloading on mechanically stabilised earth (MSE) has remained an aspect difficult to quantify in design, particularly when considering different reinforcement types, stiffness values, and facing rigidity. This study analyses several scaled model tests on MSE walls under a strip footing load with a single unloading-reloading cycle. Scaled models were constructed as part of this investigation to expand the evaluation of previously constructed full-scale tests. The strip footing load and wall deflections were measured and compared with analytical models. The failure mechanism of the soil, before and after the strip footing load, was included in the study via the particle image velocimetry (PIV) method. The results indicate that the bearing capacity of a strip footing is higher for a rigid facing than for a flexible facing. PIV analysis results for the first and second loading step formed two failure lines with the angle (π/4 + φ/2). The deflection values in the second loading step, however, were smaller than those reached during the first loading in small-scale tests. Good agreement was observed between the proposed analytical method and experimental results for the second loading step, after taking into account the preloading effect.

No abstract

Based on the phononic crystal slab resonators, a new structure is proposed which has the operation similar to electromagnetically induced transparency (EIT) in the optical domain. This structure includes two resonance microcavities and interacts with each other. Due to the interaction between two microcavities, the transmission coefficient will be off while in noninteracting case it is on. Finite element method (FEM) is utilized to simulate the performance of the structure. The transmission spectrum of the structure is investigated in different states such as different coupling between two resonators. Also, it is shown that with control the coupling coefficient between two cavities, the acoustic transmission will be controlled especially in the resonance frequency of the cavities before coupling. Finally, the nonlinear properties of this phononic structure are investigated and the changes in the mass density due to this nonlinearity are discussed.

No abstract

-In this paper the behavior of reinforced earth walls with rigid and flexible faces under strip footing load was studied by numerical analysis. In one numerical model the strip footing load was free to have horizontal and vertical movements and in another the horizontal movement of the strip footing load was restricted. By considering these two different models, the results of 2D and 3D numerical analysis (Plaxis) were compared with the full scale test results about the horizontal earth pressures, lateral wall deflections and consequently maximum tensile force on reinforcement layers. For modeling the compaction loads in each layer two equal distributed loads were considered in the top and bottom of each soil layer and also the influence of sidewall friction was studied in a 3D numerical analysis. Results showed that there is good agreement between 3D numerical analysis and full scale test results by considering the horizontal restriction for the strip footing load.