Investigaciones Geofísicas para la caracterización de la zona de deslizamientos, Pungalapampa - Puninhuayco - Alao, Chimborazo, Ecuador

Abstract

Road construction involves filling and excavation procedures, leaving slopes susceptible to geological, hydrological and geomorphological factors, increasing the risk of instability and threatening road infrastructure and surrounding communities. The Chimborazo Province in Ecuador, due to its geographic location, diverse topography with structurally complex soil strata and variations in subsurface stratigraphy, requires detailed investigations focused on geophysics and in situ soil testing. This study assesses slope stability by correlating geophysical and soil tests to generate slope stability measurements. The applied methodology is based on the analysis of surface conditions, application of geophysical exploration, geotechnical characterisation, analysis and slope stability strategies. In the characterisation of the slope, three altered test pits were made where it was determined that there are metavolcanic materials, gravel and colluvial geologically. By correlating geophysical tests, it was determined that in the centre of the slope, the most critical apparent resistivity values (90-140 Ω m) correspond to colluvial deposits. For stability, it is proposed to terrace the slope surface with crown ditches at each level due to the presence of water holes and, in the most critical areas, to place reinforcement mesh over the vegetation. The existence of seepage zones on the slope was determined as a triggering factor for instability. These strategies serve as a basis for decision-makers in improving road connections and socioeconomic development in Andean rural communities. Keywords: Electrical resistivity, transient electromagnetic method, stratigraphic profiles, landslides and hazards.