## 1 Introduction
The first part focuses on the fundamental aspects of the building and its environment, including a detailed description of the building's geometric features, construction materials, and structural characteristics. It also covers the seismic context of the region, encompassing historical seismic activities and the specific ground motion records used in the study. Additionally, ambient vibration tests are conducted to determine the building's dynamic properties, such as its natural frequencies and mode shapes. Finally, a linear elastic model of the building is developed using finite element software, incorporating both bare and infilled frame representations to capture the structure's behaviour under seismic loading. The second part delves into the advanced seismic assessment techniques employed to evaluate the building's performance under earthquake conditions. This includes nonlinear modelling of the building using finite element software, considering both static and dynamic analysis methods. Appropriate ground motion records representing two limit states, 'Damage Limitation' and 'Severe Damage', are selected to assess the building's response under different seismic intensities. The structural response is analysed in detail, considering both global parameters (e.g., top displacement, base shear, inter-storey drift ratio) and local parameters (e.g., rotation, shear, and capacity-to-demand ratio, C/D) to comprehensively evaluate the building's performance under seismic loading. Finally, the building's seismic response under different analysis methods, including linear elastic analysis, nonlinear static pushover analysis, and nonlinear dynamic time history analysis, is compared. The last part summarises the key findings of the study, highlighting the importance of integrating field monitoring data and advanced modelling techniques to achieve a more realistic and practical assessment of seismic vulnerability. _Aims, Focus, and Limitations_  
This research paper has presented an assessment of the seismic vulnerability of a hospital building in Orihuela, Spain, based on the integration of field monitoring data with advanced numerical analyses. The results provide some interesting insights into the seismic behaviour of mid-rise reinforced concrete structures and can be transferred to similar typologies but mainly to buildings from a similar era with comparable design features. This study underlines the need to include the effects of bidirectional ground motion and detailed modelling for proper vulnerability assessment. The present study represents a further step towards seismic vulnerability assessment; some shortcomings, however, have to be pointed out. Material properties and actual in situ conditions may vary considerably from what was assumed in the original design. Calibration of the numerical model was performed mainly by using available documentation and sensor data rather than direct material testing. This limitation shows that the sensitivity analyses and updating material property models using laboratory or field tests should be included in future studies. The other limitation is that the analysis has been restricted to only one hospital block; although the findings can be generalised for similar typologies, they may not generalise fully to all structures. Accidental eccentricity effects, as recommended by the design codes for simplicity, have been excluded. While the selected ground motions realistically represent the seismic ground motions, more scenarios would create a greater understanding. Future work should be conducted on what retrofitting measures can or may enhance the seismic resilience, and further recommendations on improving the safety of similar structures will be made.