Peru has a significant number of constructions of high historical and cultural value distributed along the country. Among these archaeological remains of great significance, there are multiple ‘Huacas’, which are pyramidal earthen constructions often built for sacred or religious purposes. Some of the many existing huacas have been damaged due to exposure to severe natural and anthropogenic hazards.
The selection of the best preservation or intervention strategies of these archaeological earthen constructions is a very challenging process that is often hampered due to the difficulty to define in-situ conditions. The complexity of the conservation efforts is further increased due to the variability, and often partially known or unknown, properties of the construction materials coupled with unknown construction techniques and sequence used in these earthen structures. Additionally, the variability of boundary and foundation conditions, and other intangible conditions, further complicate the preservation and intervention strategies for these Peruvian heritage. In the paper Structural and Geotechnical Engineering Assessment of Huaca de la Luna - A Massive Earthen Moche Culture Pyramid in Northern Peru, by Rafael Aguilar et al., published in Journal of Cultural Heritage, Vol. 34, 2018, Pages 83-94, https://doi.org/10.1016/j.culher.2018.04.006, the authors report the results of a comprehensive engineering analysis for understanding the current structural damage condition of a sector of one of the most representative archaeological complexes in Perú: the main Moche culture pyramid of Huaca de la Luna. This pyramid is estimated to be built in stages with adobe masonry between 100 and 600 A.D., then buried under eolian deposits accumulated over many years and eventually discovered and excavated in the early 1990s, when severe structural damage was identified near the NW corner. Recently, an interdisciplinary team carried out an engineering diagnosis involving: detailed surveying and mapping of the geometry of the complex, multi-scale characterization of the pyramid material components, geotechnical assessment of underlying foundation conditions, and advanced numerical modeling to help evaluate the possible reasons for the observed structural damage. Based on this study, the hypothesis believed to adequately explain the observed damage is the occurrence of uneven settlements of the structure associated to foundation soils that at the pyramid site have a marked variable thickness due to the presence of a sloping bedrock.
The study confirms the applicability of sophisticated engineering methods for performing engineering analyses in complex massive structures, which may allow understanding structural issues in archaeology and planning appropriate structural conservation strategies.