The use of dynamic drobing for evaluation of undrained shear strength and compaction percent in fine-grained soils

The Dynamic Probing is an important test in site investigation and geotechnical studies. It is used for determination of situation and specification of soil layers when the depth of exploration is moderate. In our country the last few years the use of this test has been widely used to replace the standard penetration test. In this paper، the experiences to use of types of dynamic probing rigs and the errors and mistakes that can occur in these experiments is discussed. Then the accuracy of this test is studied to evaluate the specification of fine-grained soils. The most important innovation of this research is the proposition of the new correlations between cone dynamic resistance and undrained shear strength and so compaction percent in fine-grained soils. Finally، it is hoped the results of this research can be used to correction existing errors in usage of dynamic probing test. The paper encourages the wider application and further development of this test for site investigation in fine-grained soils.