## 1 Introduction
[11] applied nonlinear dynamic simulation to Portuguese adobe buildings, introducing novel damage metrics (crack propagation and volume loss) to derive fragility and fatality risk curves. [PERSON] et al. [12] explored seismic vulnerability of Chinese earthen buildings through statistical models. Despite these significant contributions, many challenges remain in the field. The seismic behavior of adobe structures is complex and often nonlinear, involving multiple failure mechanisms such as rocking, sliding, and cracking. Experimental data on the inelastic response of adobe is limited, particularly for full-scale structures under realistic seismic loading. As a result, there is a strong need for advanced numerical tools that can accurately capture the nonlinear behavior of adobe buildings, predict critical failure modes, and assess seismic capacity in a performance-based framework. The calibration of these models remains challenging due to the variability in material properties and construction techniques, and their application to real-world heritage structures is still limited. Each historic adobe structure presents unique challenges that necessitate a case-by-case study. Factors such as architectural layout, construction quality, prior damage, and past interventions can differ widely and influence seismic behavior. Thus, continued in-depth assessments of individual heritage buildings are essential to refine our general understanding. This study contributes to closing this gap by presenting structural performance and seismic safety assessment of the Church of Santo Tomas de Aquino, a 17 th-century adobe church located in Rondocan, Cusco, Peru. The church comprises a single nave with a presbytery and two annees (a baptistery and a sacristy), with thick adobe walls supporting a timber roof system composed of wooden trunks and clay tiles. Some walls are strengthened with buttresses. The building underwent conservation interventions between 1994 and 1997. The present research was developed under the auspices of the Getty Conservation Institute (GCI), with fieldwork, testing, and numerical modeling conducted by the University of Minho. The main objective of this work is to evaluate the seismic performance and safety level of the church using advanced nonlinear numerical modeling techniques. A macro-modeling approach is adopted, treating adobe and stone masonry as homogenized continuum materials and incorporating nonlinear behavior through a total-strain rotating-crack model. Material properties were derived from in situ testing and literature data, and the model was calibrated using results from ambient vibration testing. The assessment integrates nonlinear static (pushover) and kinematic analyses to identify critical collapse mechanisms and to estimate the seismic capacity relative to the seismic demand as defined in the Peruvian seismic code [13; 14]. Particular emphasis is placed on the behavior of the lateral walls and facades. The methodology involves (1) the development of a finite element model including foundations, walls, and timber tie beams; (2) the calibration of material properties based on dynamic identification tests; (3) the execution of pushover analyses along the principal axes to derive capacity curves and to identify potential failure mechanisms; (4) the evaluation of performance against the Damage Limitation (DL) and Life Safety (LS) limit states using kinematic analyses; and (5) the interpretation of the results to assess structural safety. Thus, this work also contributes to the growing body of knowledge on the seismic assessment of heritage adobe buildings by demonstrating the applicability and limitations of advanced numerical tools within a conservation-driven framework. A key contribution of this work is the integrated analytical-numerical strategy, which combines kinematic limit analysis with nonlinear FEM modeling.