Problem jednoznacznego ustalenia parametrów wytrzymałości na ścinanie odpadów powęglowych i poenergetycznych

Previous researches conclude that coal mining waste and fly ashes are useful in many kind of engineering – especially in building of embankments. In fact that the embankments transfer self weight and external loads, determination of strength parameters is very crucial. The problem of well-determined shear strength parameters conducts to searching alternative investigation methods. In the aim of credible determination of strength parameters of anthropogenic soils, the half-back analysis have been proposing. The paper presents the results of two investigation method: direct shear and limit bearing capacity analysis of slope models. Results of the tests were combined together, for verification of a relationship between shear strength obtained during laboratory tests and possibility slope failure to be initiate in embankment models made of the waste materials. In consequence of the methods combination and apply of some indexing factors into analysis, a real values of the shear strength were obtained in a specific working conditions. Proposed indexing factors can be use to examine what strength parameter, determined using direct shear test, have to be modify. In the analysed waste materials incorporated into embankments treated by braking load, the shear strength parameters determined in direct shear apparatus used for stability analysis, did not confirm stability failure phenomena what has occurred. Investigation of shear strength parameters of coarse minestone waste material in direct shear box apparatus overstate in significant way the value of cohesion. In case of fine size fly ash, the direct shear box test overstate the value of friction angle. It has to be postulated in attention of earth structure safety exploitation, the strength parameters of anthropogenic soils should be determine in real work conditions. If it is not possible, the laboratory tested strength parameters should by modify using tests simulating real work condition of the structure. A testing method used for obtaining the shear strength parameters of coarse and fine size granular waste material, strong interacting on the boundary conditions in test. Shear strength parameters of the tested waste materials are strong associated with the loading path. In consequence, is very crucial what are the work and test conditions of the material.