## 1 Introduction  
Pile-supported wharves (PSWs), commonly used as port structures, provide platforms for loading and unloading goods and passengers from ships. Variations of the pile configuration of PSWs include batter pile and vertical pile foundation systems. A commonly used PSW pile type in Indonesia is a prestressed concrete pile with closed-ended circular hollow sections, known as a spun pile [1]. Spun piles in marine environments are frequently damaged by corrosion during their service life [2, 3]. As corrosion propagates, damage due to the expansion of corrosion products (rust) is characterized by cracking, spalling, and delamination of the concrete cover [4]. Corrosion can have a significant impact on the seismic performance of PSWs. A numerical study by [PERSON] et al. [5] found that corrosion could cause a reduction in the stiffness and strength of the piles, leading to increased displacement and a decreased reliability index of the wharf foundation under horizontal load. Therefore, the nonlinear seismic analysis of corroded PSWs is essential to ensure their structural integrity and safety during earthquake events. Design codes for port facilities [6; 7] provide guidance on earthquake-resistant PSW design based on elastic analysis to ensure that PSWs are in repairable condition after low- and medium-intensity earthquakes. During large earthquakes, PSWs may undergo inelastic behavior, and design codes for port facilities introduce strain-based displacement limits to ensure that PSWs remain structurally safe to ensure the safety of human lives. Nonlinear simulation must be employed in the seismic analysis of the response of PSWs to massive earthquakes. Pushover analysis is a reliable and effective approach for observing the inelastic behavior, seismic load capacity, and plastic hinge formation of PSWs [8]. In addition, PSW serviceability (i.e., displacement and crack width limitations) plays a vital role in these designs [9]. Fiber-based finite element analysis (FB-FEA) is a numerical technique frequently used to develop nonlinear PSW models due to the accuracy of the results [10; 11; 12; 13]. This technique has been extensively validated for its ability to accurately reproduce experimental results [14; 15; 16]. FB-FEA involves dividing the structural members into two-end frame elements and connecting each boundary to a discrete cross-section through fiber grids. The nonlinear response of the material can be considered in FB-FEA by integrating stress-strain modeling into the fiber grid to generate stress-resultant forces and rigidity terms. These are then used to calculate the forces and rigidities along the length of structural members using finite element interpolation functions that satisfy equilibrium and compatibility conditions [17]. However, only a few studies [18; 19] have employed FB-FEA for the nonlinear seismic analysis of corroded PSWs, as numerical corrosion simulations are time-consuming and require high-performance software. [PERSON] et al. [18] investigated the effect of chloride corrosion on the lateral force capacity and ductility of PSWs using FB-FEA in the OpenSees platform [20]. The results indicated that the failure frequency of concrete piles aged between 25 and 75 years increased significantly due to stress corrosion cracking and brittle fracture. [PERSON] et al. [19] assessed the seismic fragility of PSWs by considering the corrosion of concrete piles. Their results showed that corrosion considerably reduces seismic performance due to diminished structural strength and ductility over the life cycle of the PSW. Considering time-dependent deterioration caused by corrosion, fragility curves can illustrate the increasing potential for damage at various seismic intensities. The nonlinear Winkler spring model approximates the soil reaction as a series of nonlinear springs and is commonly used in nonlinear structural analysis to model the pile-soil interaction [21].