## 5 Conclusions  
With the objective of comparing the parametric SSI method with the spectral nonparametric method by means of independent programs, six records of seismic events are analyzed, both methodologies are applied, and compatible results are obtained regarding the identified frequencies and forms of vibration.  
Comparing the parametric and nonparametric methods reveals that the SSI method is less effective than the Welch spectrum identification method in the sense that the former is not able to distinguish whether the identified frequencies are rotational or translational and whether they correspond to the structure or the soil. In addition, the identification of frequencies in the SSI algorithm depends on the engineer's criteria to assign an order to the system, which makes this approach unstable since the number of identified frequencies increases as the order of the system increases, whereas most of these frequencies are not recognized by the Welch spectrum.  
The models created to determine the dynamic properties of the structure converge to similar results. However, this does not allow us to conclude that they closely approximate the reality. Implicitly, this marks a limitation that, in principle, can be improved. For this case, the seismic records are obtained from institutions, and there are detailed variables (specifically, in the signal processing subsection) for which it is not known whether they are within acceptable ranges. This limitation can be improved for future projects, where the monitoring campaign can be performed by the company itself, although it would require the acquisition of instruments. In this way, it would be possible to have better control of the variables that affect the calculation models, and the methods could be calibrated for future applications.  
The application of these two methods allows for a range of results to be obtained, whereas in the case of this project, only the frequencies of structural interest are analyzed. Nevertheless, the fact that seismic-resistant structures are directly coupled to the soil, which transfers seismic excitations, should not be ignored. This article briefly mentions the difference between a soil frequency and a structural frequency and that, by means of the methods used, it is possible to separate and work only with the frequencies of the structure. Future research should analyze these frequencies, perhaps in an approach applied to soil-structure interactions.  
Ultimately, the engineering importance of identifying the dynamic properties of structures lies in its potential for structural health monitoring, which is required for the modification of existing structures, structures subject to long-term movement or material degradation, fatigue assessment, and the development of a performance-based design philosophy [33; 34; 35].  
Conceptualization, A.L.; methodology, A.L., S.L. and F.F.; validation, A.L., S.L., F.F., M.G. and J.C.V.; formal analysis, S.L. and F.F.; data postprocessing, S.L. and F.F.; writing--original draft preparation, S.L., F.F., M.G. and A.L.; writing--review and editing, A.L., S.L. and J.C.V.; supervision, A.L. and J.C.V.; funding acquisition, A.L. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the Pontificia Universidad Catolica de Valparaiso (PUCV), grant number 039.351/2021, and the APC was funded by PUCV.  
Not applicable.  
The data presented in this study are available on request from the corresponding author. The data are not publicly available due to intellectual property.  
The authors express their gratitude to the PUCV for financing the processing of this article. Further, the authors of this paper gratefully acknowledge Professor [PERSON] for facilitating the building's collected data and structural drawings.  
The authors declare no conflict of interest.