As a result, the mechanical properties determined in the laboratory can differ appreciably from those determined in situ (Klinedist, 1972). Furthermore, it is difficult to obtain a representative sample of certain soils and properly prepare that sample to maintain it’s cohesion for laboratory tests due to disturbance. These include soils with a considerable secondary structure such as fissures, joints, slickensides, and those containing particles of rock or shells of appreciable size such as rock piles. It is, therefore, often desirable to test such soils in situ. Although the prime factor favoring the in-situ testing concept is improved accuracy and representativeness, there is a secondary compelling benefit: economics.