Permeability of lateritic soil by various methods

Soil Permeability is an important property of soil used to dimension several types of engineering works, and it can be quantified by the permeability rates. Despite of the great use, the type of the re doubts about the best way to determine de permeability rates. The main questions are: (1) the type of the method and (2) the reproducibility of samples in tropical soils. So, the objective of this work is to evaluate the permeability of a lateritic soil by comparing values of permeability coefficient determined for laboratory and in situ testing. For this, it was chosen the lateritic soil of Campo Experimental de Engenharia Geotécncia (CEEG) of the Universidade Estadual de Londrina (UEL) and four equipments: constant and variable head permeameters, Guelph permeameter and infiltrometer. The results show that all the methods present mean value of permeability coefficient on the order of 10-3 cm/s whit variation coefficient in range of 37% to 92% , except the constant permeameter. The heterogeneous structure of lateritic soil (in macro and micro pores) is the probably determinant of the variability observed.