## 3 Results and Discussion
### Evaluation of the Seismic Response of a Base-Isolated Structure  
According to ASCE 7-16 [55], Chapter 17.2.8.4. Property Modification Factors, maximum and minimum modification factors (\(\lambda\)) should be applied to account for the variability of parameters due to temperature effects, aging, environmental exposure, and contamination. The maximum and minimum values are determined using Equaititon (3) and Equaititon (4), respectively. \[\lambda_{max}=\left(1+\left(0.75\:*\:\left(\lambda_{ae,max}-1\right)\right)\:* \:\lambda_{test,\:max}\:*\:\lambda_{spec.\:max}\geq 1.8\right. \tag{3}\]  
\[\lambda_{min}=\left(1-\left(0.75\:*\:\left(1-\lambda_{ae,min}\right)\right)\:* \:\lambda_{test,\:min}\:*\:\lambda_{spec.\:min}\leq 0.6\right. \tag{4}\]  
\(\lambda_{ae,\:max},\lambda_{ae,\:min}\) = property modification factors used to calculate the maximum and minimum property values of the isolator of interest, respectively, accounting for the effects of aging and environmental conditions. \(\lambda_{test,\:max},\lambda_{test,\:min}\) = property modification factors used to calculate the maximum and minimum property values of the isolator of interest, respectively, accounting for the effects of heating, loading rate, and scraping. \(\lambda_{spec,\:max},\lambda_{spec,\:min}\) = property modification factors used to calculate the maximum and minimum values of the isolator property of interest, respectively, accounting for variations in the manufacturing process. Additionally, ASCE 7-16 [55] provides default modification values when the manufacturer is unknown and isolator quality tests are not available (Table 6). To analyze how seismic isolators exposed to environmental conditions could affect the seismic response of a building, the results of the mechanical tests were incorporated into the building model. Initially, the maximum gain and loss of horizontal stiffness, vertical stiffness, and damping were calculated based on the type of exposure. Then, an average value of increase and reduction for each property was determined to establish \(\lambda_{\text{(ae,max)}}\) and \(\lambda_{\text{(ae,min)}}\). Equations (3) and (4) were modified to consider only the modification factor accounting \begin{table}
\begin{tabular}{c c c} \hline \hline  & **Maximum Values** & **Minimum Values** \\ \hline Factor for aging effects and environmental conditions & \(\lambda_{ae,\:max}=1.4\) & \(\lambda_{ae,\:min}=1.0\) \\ \hline Factor for heating, rate of loading, and scragging. & \(\lambda_{test,\:max}=1.5\) & \(\lambda_{test,\:min}=0.9\) \\ \hline Factor or permissible manufacturing variation & \(\lambda_{spec,\:max}=1.15\) & \(\lambda\lambda_{spec,\:min}=0.85\) \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Default upper and lower limits for unknown manufacturers (Source: Table C17.2-6 (ASCE 7-16 [55]). for environmental conditions. That is, \(\lambda_{\text{test,max}}\), \(\lambda_{\text{(test,min)}}\), \(\lambda_{\text{(spec,max)}}\), and \(\lambda_{\text{(spec,min)}}\) were assumed to be 1, following the procedure used by [PERSON] et al. [38]. Table 7 presents the factors used to modify the properties of fiber-reinforced isolators in the building model. The D\({}_{\text{TM}}\) model represents the case with no change in properties, while D\({}_{\text{TM}}\) max corresponds to the model using \(\lambda_{\text{(ae,max)}}\), and D\({}_{\text{TM}}\) min corresponds to the model using \(\lambda_{\text{(ae,min)}}\). When comparing Tables 4 and 5, the values presented for \(\lambda_{\text{(ae,max)}}\) and \(\lambda_{\text{(ae,min)}}\) are lower than those proposed in ASCE 7-16 [55]. The modification factors defined by ASCE 7-16 [55] ensure that the properties used in analysis and design reflect unfavorable conditions and incorporate a safety margin by accounting for the potential degradation of the isolation system due to environmental exposure.