Weathering of Rocks in Brazil

Abstract

Weathering comprises an important mechanism controlling the mechanical behavior of Brazilian rocks in civil and mining engineering works. The intense physical and chemical weathering caused by tropical climate imposes severe changes on strength and deformability behavior of rocks and creates a complex weathering profile which must be appropriately understood in order to provide useful design information and avoid or reduce geotechnical problems. In this chapter, information is presented on the main effects of weathering acting on rocks in Brazil, focusing on the effect of the process on physical, chemical, mineralogical, and mechanical characteristics. Results of several field descriptions and laboratory results are presented. These results show that most rocks behave as soft rocks in different stages of weathering. At the end of the chapter some studies currently under development on this theme are presented.