Abstract

The south sector of Ruinas de Huanchaca (or Huanchaca Ruins) features a rock slope of around 850 m in length with a height of around 30m. The Huanchaca Ruins are the remains of an ancient silver foundry complex built in 1892 and abandoned in 1902. It is an important monument in Antofagasta, Chile. The Huanchaca Ruins and the land on the toe of the slope belongs to the Catholic University of the North. We started this preliminary stability study because there are citizens living above and working below the rock slopes. The safety of these people is a concern because there is a lack of previous information of the rock mass, poor monitoring (mainly based on satellite photographs) and regular seismic activity. Therefore, this study is aimed to perform a preliminary study of the stability of the slope in order to identify potential slope failures. A field survey of discontinuities gave us a primary division of the slope, and drove us to dividing the study area in 7 zones. Potential slope failure mechanisms were identified on four of these zones. Another zone did not show any evidence of potential failure and the remaining two zones were not accessible. On field, 3 geological areas are identified, being andesite and weathered andesite the dominant rocks. Laboratory tests on rock fragments from the slope were performed in order to provide information of the intact rock and the discontinuities. Stability analyses were performed using analytical approaches and the Rocscience software when available. Calculated Factors of Safety range from 1.1 to 2.5, indicating that a more detailed study is required.