GEOTECHNICAL CHARACTERIZATION OF TWO SOILS IN A SUBTROPICAL REGION

Abstract

The present work aims to geotechnically characterize two soils of the Guabirotuba Formation in Curitiba/PR and compare them with reference to characterization. For this, two silty soils were collected in different places in the city and in different colors: yellow and purple. The three soils were submitted to tests of real specific gravity of the grains, granulometry by sieving and sedimentation, limit of liquidity, limit of plasticity and compaction in normal, intermediate and modified energy. According to the Unified Soil Classification System (SUCS) yellow soil and purple soil are classified as sandy elastic silts (MH). The largest granulometric fraction in the two soils corresponds to silt (0.002 mm < diameter < 0.075 mm) varying in percentages of 57.6% and 53% for the yellow and purple soils, respectively. As for the clay fraction (diameter < 0.002 mm), it is smaller in purple soil (9%). The normal compaction results show the soil with maximum density of γ_dmax=13.80 kN/m³ and the yellow soil with γ_dmax=13.75 kN/m³. In the modified compaction, the yellow soil had the highest γ_dmax with 16.75 kN/m³. On the other hand, it was found that the plasticity index (PI) is higher in purple soil (21.3%) and lower in yellow soil. Although the soils were collected in different locations in the city and in different colors, they present similar geotechnical characteristics due to their same sedimentary origin and geological formation.