Análisis de estabilidad en taludes arenosos: deslizamientos en los "cabezos" de Huelva

Resum

In the “cabezos” (hills) of Huelva there have been important phenomena of instability which sometimes originated disastrous consequences. These represent topographic elevations developed mainly in the geological formations “Huelva Sands“ and “Bonares Sands“ being formed by sandy-silty material. We have studied and characterized the geotechnical properties of the levels of sands in different slopes, near Huelva’s bullring. The slopes are being affected by water superficial erosion and mass movements, which are very active in times of significant rainfall. This study is based on detailed geometric of landslides analysis and related rainfall patterns, for the time period from 1984 to 2010. In this period have been recognized the moments more actives of erosion and landslides, which coincide with increase between 44% and 85% in annual mean rainfall. On the other hand, landsliding is seen to be related to a period preparatory of 1-2 months with values of cumulative rainfall more than 300 mm and a daily intensity upper than 40 mm. Back analyses of landslides provide a peak and residual friction angles (φ’) of 17º±5º and 6º±3º, respectively. This work can serve as a starting point for the recommendation and design of preventive actions, or where appropriate, corrective of stability.