Equivalent Damping Ratio Equations in Support of Displacement-Based Seismic Design for Pile-Supported Wharves

Seismic fragility analysis of concrete pile-supported wharves based on single-degree-of-freedom model

“…Upon the backbone curve has been determined, an appropriate hysteresis rule is need to be established based on the shape of hysteresis loops for wharves. Gao et al [17] concluded that Pivot hysteresis model proposed by Dowell et al [18] can represent the hysteresis characteristic of wharf, as shown in Fig. 2, and determined the values of model parameters and .…”

“…It is suggested that Eqs. ( 2) and ( 3) from [17] can be utilized to calculate and for cast-insitu pile-supported wharf, respectively. Furthermore, Eqs.…”

“…( 4) and ( 5) can be applied to prestressed high-strength concrete (PHC) pipe pile. For piles different from those, Pivot model parameters can be determined in accordance with procedure in reference [17]. In Eqs.…”

“…However, the soils that located at the range of 10 times of the pile diameter below dike surface generally have significant impact on seismic response [14]. Thus, if clay or sand is predominant in this range, aforementioned formulas are recommended, otherwise cyclic pushover analyses should be carried out to determine Pivot model parameters with methodology in reference [17].…”

“…ground acceleration (PGA) is 0.20 g. For more information about ground motions, the readers are referred to reference [17]. Considering that this study is just to validate the reasonability of proposed procedure, the PGA is used as IM in the study for its popularity in fragility analysis.…”