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Axial forces are generated in the plates of ADAS-yielding dampers when subjected to lateral loading due to their boundary conditions. This on one hand can lead to an increase in strain level of the plates and accelerate the damage process, while on the other hand, the interaction of the bending moment with the tensile axial force leads to increasing strength, which is undesirable in the performance of ductile members. In this paper, a modified ADAS device (MADAS) is introduced to prevent undesirable interaction of axial forces, and its cyclic behavior is evaluated both experimentally and numerically. To this end, in the first step, two test specimens with different number of connection pins were prepared and subjected to cyclic loading in a rigid frame. Experimental and numerical results have shown that due to the removal of the constraint in the vertical direction, the level of forces produced by the damper is almost constant and the X-shaped plates have been able to tolerate significant number of cycles before crack initiation. Afterwards, the cyclic performance of ADAS and MADAS dampers was numerically compared individually and also when placed in the frame. Furthermore, in the frame equipped with ADAS damper, the increase in the level of forces produced by the damper led to the buckling of the braces, while the level of generated forces was totally in the expected range in the frame equipped with MADAS damper. [ABSTRACT FROM AUTHOR]

Batter piles control displacement of wharves and offshore platforms by absorbing most earthquake and berthing loads because of their high lateral stiffness. Nevertheless, structural failure caused by stress concentrated in the pile caps has been reported in past earthquakes. The present paper investigates the seismic performance of wharf models with and without batter piles using 1 g shaking table tests with harmonic excitation as well as real earthquake records. Sensitivity analysis was performed by studying the effect of the deck load, shaking frequency, embedment depth of the pile and the relative density of the soil on horizontal displacement and acceleration of the deck. A numerical investigation was conducted using 3D finite element method to evaluate the role of the pile inclination angle on the behavior of the pile-supported system. The results of dynamic analysis quantitatively indicated the defects in the batter piles under different conditions. It was also concluded that, although the amount of deck displacement decreased when the inclination angle was reduced, the axial force generated in the batter piles showed no upward or downward trend and maximized at a specific angle. • The wharves with batter piles exhibits significantly lower horizontal displacement and larger Fourier amplitudes. • Soil relative density and piles embedded depth are indirectly related to wharves' deck displacement. • Using inclined piles leads to the concentration of forces, and structural failure. • Axial force of inclined piles does not necessarily increase by raising the batter angle. [ABSTRACT FROM AUTHOR]