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The paper presents the procedure for determining the factor of safety (FoS) using the strength reduction method (SRM) for the case of a concrete damage plasticity constitutive model. The SRM was originally used in a slope stability analysis and in its original form, this method was applied by reducing the shear strength of the material. Since damage in concrete occurs due to exceeding the normal stresses in the principal directions, and not due to exceeding the shear strength, this method was modified and adapted to the concrete damage plasticity constitutive model. Instead of reducing the failure surface, the parameters which describe the mechanical behavior in the case of uniaxial compression and uniaxial tension were reduced. In this way, the reduction of stress and the corresponding strain was carried out in the entire range of total strain, without changing the shape of the failure surface in the deviator plane. For the proposed methodology, a numerical algorithm was developed and implemented into the software PAK. The algorithm was verified through test examples and the obtained results were compared with analytically calculated FoS. The excellent agreement is observed between the FoS obtained by applying the proposed algorithm and the analytically calculated FoS. [ABSTRACT FROM AUTHOR]

The procedure for identifying concrete damage plasticity material model parameters is presented in this paper. Concrete damage plasticity material model represents a constitutive model which is based on a combination of theory of plasticity and theory of damage mechanics. This material model is often used in solving geotechnical problems due to its realistic description of mechanical behavior of concrete material. Theoretical basis of concrete damage plasticity material model and material parameters identification procedure are presented in this paper. Proposed identification procedure is applied on experimental data from uniaxial compression and tension load-unload tests taken from literature. By applying experimental data, stress-strain curve is created. Based on stress-strain load-unload curve, stress-plastic strain and stress-degradation dependences are created which are necessary for material parameters identification. Using these dependences material parameters are determined. Verification of estimated parameters is performed in PAK software package using concrete damage plasticity material model. Finite element model is created for numerical simulations of uniaxial compression and tension tests. Numerical simulation results are compared with experimental data. By comparing numerical simulation results and experimental data it can be concluded that this procedure is effective for determining concrete damage plasticity model parameters. [ABSTRACT FROM AUTHOR]