Determining undrained shear strength and Atterberg limits simultaneously by an innovative device, Mud Press Machine

The determination of Atterberg limits (LL and PL) holds significant importance in geotechnical studies. Setting of these parameters properly enables important engineering behaviors of soils to be easily predicted. However, these methods have many limitations and uncertainties. These drawbacks of the test methods affect the results significantly. Likewise Atterberg limits, the undrained shear strength (su) which represents the total shear strength of soils may also be crucially important in certain geotechnical studies. Determining the su of soils is sometimes very challenging, especially for very weak soils due to sampling difficulties. This investigation aims to use the Mud Press Machine with a very significant number of soils to determine the Atterberg limits and su simultaneously. For this purpose, 500 sets of tests were carried out on 100 different soil samples with a very wide range of plasticity. Multivariate regression analyses were performed between the force values obtained from the MPM tests and the other three parameters (LL, PL and su) obtained from the conventional tests and the relationships between them were examined. Notably high correlations were observed between the MPM results and the conventional tests. The results indicate that the MPM device can determine both the Atterberg limits and undrained shear strength of soils in one simple test and the uncertainties and difficulties in other methods can be overcome with this innovative method.