Load velocity influence on changes of soil consolidation and permeability parameters in CL-type tests

摘要

Obtaining the reliable values of filtration consolidation parameters depends on appropriate programming of load velocity. The paper presents a critical assessment of the criteria for selecting the load velocity with regard to a theoretical model of consolidation under the constant rate of load (CRL). A key element of interpretation is to distinguish three stages of investigation: mobilization of pore pressure, steady phase and unsteady phase. Reliable values of filtration consolidation parameters are obtained during the steady phase determined on the basis of dimensionless test parameters, standardized for CRL: the pore pressure and relative time of consolidation CL (continuous loading). In order to assess the trends in changes of filtration consolidation properties of the Krakowiec Formation, clays were chosen for investigations. The tests were performed on undisturbed samples and using Middle Miocene soil pastes at different load velocities to propose a method to choose appropriate test speed in CL tests.