A soil sampler was designed and constructed to extract and evaluate undisturbed 75 mm diameter core samples at a depth of up to 0.60 m. Soil sample quality was evaluated and compared using traditional methods. The sampler consisted of a removable polyvinyl chloride (PVC) standard sewage pipe to receive the soil, an aluminium encasing sleeve and a steel conic cutting, surrounded by an auger with three cutting chisels. The soil sampler was adapted to a specially-designed off-road vehicle (VAS). The VAS samples were compared with undisturbed samples taken from a soil block by the following laboratory tests: soil bulk density, triaxial undrained compression test and consolidation test. It was concluded that the soil samples obtained in clay soil using VAS have soil bulk density values, triaxial and consolidation tests results with no statistical difference with 95% of confidence, when compared to soil samples obtained from an undisturbed soil block. The equipment used was easy to operate and adequate to collect undisturbed samples of clay soil, with sample quality similar to that obtained by traditional methods, such as the cylindrical metal sampler and the soil block. It can be useful in the sampling process for soil mapping when using GPS.
undisturbed soil sample; sampler; off-road vehicle; clay soils