Experimental and Numerical Evaluation of Out-of-Plane Seismic Performance of Traditional Dry Stone Retaining Walls in the Central Andes Region

Abstract

The population that lives informally on the slopes of some cities in the Andes is at high seismic risk due to the lack of technical advice to build their homes, which are settled on non-compacted fill supported by pircas (traditional dry stone retaining walls). The objective of this work was to evaluate the seismic performance of these walls through pseudo-static tests and numerical models applying the discrete element method (DEM), simulating forces in the out-of-plane direction. Three walls of 1 m and three of 1.5 m in height were built. These are the most common dimensions found in the study area (Lima). It was observed that the most frequent failure is due to delamination and overturning of the pircas. It is estimated that the average ultimate resistance to displacement, obtained experimentally, of the walls with heights 1 m and 1.5 m was 31% and 24% of the weight, respectively. For the numerical models, the parameters of the contact forces (stiffness and friction angle) were calibrated using the experimental results. It is concluded that the walls can improve their capacity with a better construction practice.