**3.1 The lateritic soils in Brazil**

As mentioned above, studies on tropical soils often exhibit a higher degree of difficulty because of their mineralogical, textural, and structural variability, and this is not an exception in the Brazilian territory. Several researchers have studied the behavior of these soils both in the context of the execution of works and for experimental purposes, in universities and research centers. One aspect to highlight is the contribution of foreign companies and professionals in recent years to enriching the knowledge and discussion of engineering problems from the exchange of ideas [30].

Although the country has soil surveys developed by EMBRAPA (Brazilian Agribusiness Research Company) and other research bodies, these are mainly for use in agriculture, without the geotechnical focus [31].

**Figure 3.** *Alteration profiles of tropical soils [16].*

*Tropical Soils: Considerations on Occurrence and Characteristics and Studies in Brazil DOI: http://dx.doi.org/10.5772/intechopen.103947*

#### **Figure 4.**

*Distinct mesoscopic aspects of the lateritic materials at the Rondon do Pará bauxite deposit. A. Contact between Belterra clay and Nodular Bauxite; B. massive bauxite; C. fragments of iron crust with hematite; D. ferruginous bauxite with oxyhydroxide clasts in a gibbsite matrix, strong goethitized; E: massive bauxite base with kaolinite; F. mottled zone in the basal clay. Approximate scale, drillcore HQ diameter of 9.65 cm (3.5*″*). Gbs-Gibbisite, Gth-Goethite, Hem-Hematite, Kln-Kaolinite [20].*

In this context, the peculiarities of Brazilian soils (occurrence, constitution, formation, properties, indices, and environmental conditions) are therefore different from the conditions found in the temperate climate regions where the traditional soil classification systems were developed [4, 7].

It is thus observed that the physical, chemical, biological, pedological, and geomorphological processes vary throughout the area of occurrence of these soils and also in Brazil, where they are distributed over 80% of the territory, as shown in **Figure 5** [32].

Since knowledge of where a work will be deployed depends primarily on well-designed and developed local research, one of the important aspects for the development of an assertive engineering project is the description of the soil profile. Expedited forecasts of collapsible or expansive soil behavior could be inferred from pedological classifications, where in addition to soil identification and classification, information about soil genesis is provided. This is because there is a close dependence on the tropical humid climate of the changing soils in relation to the matrix rock, as, for example, granites decompose originating mycaceous soils with particles of clay and sand, and basalts change basically in clays [3].

Of course, the use of generic profiles is inadvisable and local research can in no way be replaced. Consequently, the use of the geological description of the soil profile in engineering projects is considered essential, and the ignorance of the soil profile leads the designer to make predictions with a degree of uncertainty above that tolerated in the standards. On the other side, when the origin was known and the characteristics of the whole region and of the profile in an individual place the

**Figure 5.** *Area of occurrence of laterite soils in Brazil represented by dark brown colors and hachuras [32].*
