## 1 Introduction  
Geomechanical classifications have been used since 1946 to characterize rock masses, mainly oriented to tunnel construction. The two most widely used geomechanical classifications are the Q-index [1] and rock mass rating (RMR) [2]. These classifications determine a quality index, estimate rock mass behavior, and provide guidelines to select the rock support measures in tunnels, open pit mines, and/or slopes [3, 4]. The RMR was conceived for tunnels and adapted for foundations, open pit mining, and rock slopes and is probably the best-known and most commonly used geomechanical classification for the preliminary characterization of rock mass quality. Other classifications modify the RMR for rock slope analysis by adding correction factors such as the slope mass rating, SMR [5], initially employed for civil construction, and the mining rock mass rating, MRMR [6], used in open pit and underground mining. Although the Q-index is the leading classification system for underground design, it was not systematically applied to slopes until 2015. The Q-slope classification [7] modifies some Q-index parameters and enables the application to rock slopes. Q-slope is becoming very popular and has been applied to over 400 individual case studies in many countries and different lithologies [8]. Nevertheless, SMR remains one of the most used geomechanical classifications for slope analysis [9; 10]. SMR has been used for over 30 years, providing valuable insight into expected slope behavior. In contrast, the more recent Q-slope is an empirical rock slope engineering method used to quickly assess slope stability with minimal assumptions [11; 12; 13]. SMR and Q-slope have been successfully applied to geomechanically characterize civil construction rock slopes, global natural slopes, and quarries. However, its application and reliability in the Andean region remain relatively underexplored. The application of SMR and Q-slope in the Andean part of South America can fill a knowledge gap in terms of rock types and stability assessments on high mountain slopes. Slope movements have become one of the most dangerous natural hazards, causing many human losses and substantial material damage annually [14]. With instabilities in rocky slopes, different methods can be used for stability evaluation. From a practical point of view, there are three main approaches to the study of rock slope failures: (a) application of geomechanical classifications and empirical analysis; (b) kinematic assessment or application of limit equilibrium methods (for block and circular failures), and (c) application of numerical methods such as finite element, finite difference, and discrete element approach. (b) and (c) present simple applications and require less information to generate reliable models; therefore, they are the most used approaches in the feasibility stages of a project. In the study of shallow rock slopes--those without stress effects, with relatively homogeneous rock masses and heights under 50 --limit equilibrium and kinematic are the most used methods, followed by geomechanical classifications. The Q-slope [7; 8] indices can be applied to heavily fractured rock masses, presenting circular, wedge, toppling, or planar failures due to weak rock masses. Limit equilibrium methods can use slice methods and kinematic analysis. The three approaches are frequently combined in practice to study rocky slopes, with each technique providing complementary information [14; 15]. Since its development in the 1970s, the Q system has been widely used in multiple projects related to civil engineering and underground mining [7]. In 2015, the empirical Q-slope method was presented, enabling technicians responsible for ongoing construction works to evaluate the stability of excavations and rock slopes as it progresses, correcting the inclination angles of the rocks in the field and profiled slopes [16].