Abstract:
Slope stability is a key aspect of geotechnical engineering, particularly in mountainous regions with steep gradients, active seismicity, and high precipitation levels. The Sopladora Hydroelectric Power Plant, located in southeastern Ecuador, is part of the Paute Integral Hydroelectric Complex and has a generation capacity of 487 MW. In the study area, previous investigations have identified 21 landslides, which pose a potential threat to Ecuador’s electric power generation system. This study aims to propose mitigation strategies using geophysical techniques, geotechnical correlation, and analysis to rehabilitate landslide-prone areas along the access road to the Sopladora powerhouse. Field visits were conducted to delineate specific zones for the investigation of unstable slopes. Seismic and geoelectrical profiling predominantly confirmed the presence of weathered/saturated schists (6–300 Ω∙m) and moderately to slightly weathered schists (300–3000 Ω∙m). Based on the geophysical data, geotechnical correlations were established for parameters such as cohesion, friction angle, and unit weight. Numerical modeling using Slide2 (limit equilibrium method) and RS2 (finite element method) was performed to evaluate the factor of safety (FS) of the slopes, identifying high-risk instability zones with FS values ranging from 0.58 to 0.92 under static and pseudo-static conditions. Based on geological studies and slope geometry, a stabilization solution is proposed involving active anchors arranged in a staggered pattern (“tres bolillo”), shotcrete lining (f′c = 210 MPa, thickness = 0.08 m), and the installation of horizontal drains. The implementation of this solution seeks to ensure the safe operation of the hydroelectric facility—allowing for regular maintenance of its turbines—and to support the country’s energy sustainability within the Paute hydroelectric complex.
Description:
Slope stability is a key aspect of geotechnical engineering, particularly in mountainous regions with steep gradients, active seismicity, and high precipitation levels. The Sopladora Hydroelectric Power Plant, located in southeastern Ecuador, is part of the Paute Integral Hydroelectric Complex and has a generation capacity of 487 MW. In the study area, previous investigations have identified 21 landslides, which pose a potential threat to Ecuador’s electric power generation system. This study aims to propose mitigation strategies using geophysical techniques, geotechnical correlation, and analysis to rehabilitate landslide-prone areas along the access road to the Sopladora powerhouse. Field visits were conducted to delineate specific zones for the investigation of unstable slopes. Seismic and geoelectrical profiling predominantly confirmed the presence of weathered/saturated schists (6–300 Ω∙m) and moderately to slightly weathered schists (300–3000 Ω∙m). Based on the geophysical data, geotechnical correlations were established for parameters such as cohesion, friction angle, and unit weight. Numerical modeling using Slide2 (limit equilibrium method) and RS2 (finite element method) was performed to evaluate the factor of safety (FS) of the slopes, identifying high-risk instability zones with FS values ranging from 0.58 to 0.92 under static and pseudo-static conditions. Based on geological studies and slope geometry, a stabilization solution is proposed involving active anchors arranged in a staggered pattern (“tres bolillo”), shotcrete lining (f′c = 210 MPa, thickness = 0.08 m), and the installation of horizontal drains. The implementation of this solution seeks to ensure the safe operation of the hydroelectric facility—allowing for regular maintenance of its turbines—and to support the country’s energy sustainability within the Paute hydroelectric complex.
Keywords: Geotechnics, slope analysis, mitigation, geophysics, limit equilibrium, finite elements, and retaining structures.