Estudio geológico y geotécnico para delimitar zonas susceptibles a fenómenos de remoción en masa, en el área urbana del Cantón San Juan Bosco

Abstract

This study aims to delimit the vulnerable areas to mass movement phenomena, in San Juan Bosco urban area. It was used the Mora Vahrson Modified methodology, by applying methods and geological techniques developed in the field and desk study, also the observation and interpretation of various outcrops, mass movements and drops, in order to obtain lithological and geomorphological information. Moreover, laboratory tests were conducted, such as granulometric tests, soil moisture, plasticity and liquid limit, for the soil geotechnical classification, based on the AASHTO and SUCS regulations. Furthermore, document review was implemented, both in theoretical framework devising, and for obtaining rainfall and seismicity data about nearby places to define boundary areas. Mentioned data were processed through the Geographic Information System (GIS). This study lithologically recognized geological formations locally, such as Napo Formation, Margajitas Group, comprised of scretaceous sedimentary rocks and contemporary quaternary deposits. As a result, a final map was developed about the vulnerable areas to mass removal phenomena, itemizing three types of areas of different levels: very low, low and moderate. In conclusion, the most representative area is moderate, which means level 3 and, regarding the whole area investigated, represents 90%. It is recommended to conduct more specific tests in the most vulnerable areas, to know the mechanical properties of the land and rocks of the subsoil in the areas of construction or engineering projects.