Geologia Estrutural na previsão e contenção de queda de blocos em encostas: aplicação no Granito Santos, SP

Abstract

STRUCTURAL GEOLOGY FOR PREVENTION OF ROCKFALL ON SLOPES: APPLICATION IN THE SANTOS GRANITE, SP. Anthropogenic actions such as cutting, deforestation and/or overloading can affect the stability of natural slopes. This synthesis describes the main Structural Geology techniques for prediction of landslides and rockfalls on hillsides and rocky slopes. The analytical methods for evaluating slope seek for potential risk situations and to minimize the risk of landslides and rockfalls. It is necessary to know the massif properties, as lithological composition, degree of weathering and consistency of rocks, and types of discontinuities. We have evaluated the results of a survey carried out on a slope between Santos and São Vicente, SP, with rappelling techniques. There, a consulting firm has recognized the major systems of fractures, and identified blocks in unstable situations, recommending the eventual removal or stabilization. Nowadays, the geological-structural studies stress out the importance of exfoliation joints as features that can promote, due to the progressive weathering and rock breakdown, the formation of slabs and gradual loosening of rock mass down the slope.