 Large scale testing should be assessed on a case by case basis.Slope failure or settlement of a structure after field tests have been conducted are examples of phenomena which may be considered as back analysis, this be conducted successfully when accompanied by a full investigation to determine the ground and ground water conditions.Geophysical surveying can be useful in site investigation for determining layers of rock other geological features, locating aquifers, mineral deposits, voids – natural or man-made and engineering properties of the ground.