Effect of Eastern Architecture and Sloping Foundation Conditions on the Static and Dynamic Response of the Adobe Pyramid Huaca De La Luna (Perú)

The Moche civilization constructed the monumental adobe complex Huaca de la Luna in phases from 100–650 CE. Its main stepped pyramid is the focus of this study. Located at the foot of Cerro Blanco, near coastal Trujillo, Perú, the structure is subject to Pacific Ring of Fire seismic activity. Damage to the northwest corner and looting on the north and west façades have motivated structural analysis using nonlinear FE models that treat the base of the pyramid as directly attached to the underlying sloping bedrock and soft soil. The present work introduces the following factors to a 2D cross-section model: (a) an interposing sand layer of varying thickness between the adobe construction and the sloping bedrock of Cerro Blanco, (b) a frictional interaction at this interface, and (c) architectural additions to the main pyramid’s east side. Using a Design of Experiments (DOE) methodology, this study investigates how these factors affect the monument’s lateral capacity, measured through the time-evolution of strain and plastic dissipation energy. Results indicate that the interposing sand layer and construction on the east side influence the results the most. Consequently, further on-site survey should focus on a more accurate definition of these features. Simulations are performed in Abaqus/CAE Explicit using the concrete damaged plasticity and the Mohr-Coulomb formulations for modeling adobe and sand, respectively. Statistical analysis is performed in the statistical software JMP version 16, primarily focusing on Analysis of Variance (ANOVA).