## 1 Introduction  
In marine environments, the corrosion of steel bars embedded in the concrete of structural components, such as beams or piers, is a common phenomenon. Corrosion reduces the mechanical properties of steel bars [1, 2, 3]. Generally, there are two types of corrosion: pitting and uniform. Both types of corrosion affect the yield stress and Young's modulus of the steel bars [3]. However, some researchers have demonstrated that corrosion causes a decrease only in the bar area [4, 5]. Therefore, in [4], the loss of bar area was utilized to simulate the corrosion of longitudinal bars. Although researchers have different opinions about the mechanical properties of corroded steel bars, they agree that the corroded steel bars reduce the structural capacity [4, 6, 7, 8, 9, 10, 11, 12, 13, 14]. [PERSON] and [PERSON] [4] stated that the probability of failure of corroded bridge systems increases with the corrosion ratio. The cyclic behavior of corroded reinforced concrete piers was investigated by [PERSON] et al. [12], and the results implied that corrosion causes a significant degradation in the structural capacity. Other researchers have also assessed the fatigue failure of corroded bridge structures [15, 16, 17, 18, 19]. In [16], a simplified approach was proposed for the corrosion fatigue assessment of steel structures in aggressive environments; and in [17], statistical time features were used for global corrosion assessment in a truss bridge from vibration signals. Based on the above studies, it can be concluded that corrosion induces a degradation of the structural capacity. Therefore, it is necessary to reinforce corroded structures to enhance their performance. Many reinforcement methods have been developed and utilized to strengthen buildings or bridge structures in civil engineering [20]. These methods include: increasing the concrete section [21, 22, 23, 24, 25], or using bonded steel plates [26, 27], carbon fiber-reinforced plastic [28, 29], or glass-fiber-reinforced polymers [30, 31]. Bonded steel plates are commonly used to reinforce bridge piers, beams, or other structural components to enhance their flexural and shear capacities. [PERSON] and [PERSON] [24] demonstrated that external tendons are effective in reinforcing continuous beams by improving their ductility. GFRP composite sheets are effective in improving compressive strength, and increasing the number of GFRP layers can significantly enhance the load capacity of a column [30]. Fiber-reinforced polymer composites are widely used in engineering for retrofitting bridge piers. In [32], the effectiveness of carbon-fiber-reinforced polymer jackets on retrofitted bridge piers was evaluated, and the findings indicated that FRP jackets improved the ductility capacity of plastic hinges; thus, this approach successfully eliminated the potential collapse of bridge columns subjected to strong earthquakes. Numerous efforts have been made to evaluate the structural capacity of strengthened structures. Among these studies, some have focused on the safety evaluation of deteriorated structures with different retrofitting methods subjected to earthquake loads or other natural hazards through fragility analysis [33]. However, earthquake events in the past have shown that many aftershocks may follow a mainshock, and these aftershocks with high magnitudes may also have the potential to damage bridges or building structures, especially those damaged in the mainshock [34; 35; 36; 37; 38; 39; 40; 41; 42; 43; 44; 45; 46; 47; 48]. [PERSON] et al. [35] suggested that the influence of mainshock and aftershock sequences (MAS) on seismic loss should be further investigated. In [49], the findings imply that aftershocks have a remarkable influence on the seismic behavior of low-ductility RC frame structures, and the degree of effect is determined by the magnitude of the mainshock. In these previous studies, researchers have focused on the mechanical properties of corroded steel bars and the carrying capacity of corroded structures.