Modeling the progressive failure in the slope using random radial point interpolation method

In conventional analyzes of soil slopes failure, resistance parameters are assumed to be stable even in large strains without change. However, during the rupture, soil resistance exhibits maximum and residual amounts, and its strength increases prematurely by increasing the plastic strain. In addition to changing soil resistance parameters in the progressive mechanism, the non-uniform nature of the soil also causes spatial variations of these parameters. Therefore, geotechnical systems should be considered in terms of the uncertainty of soil parameters values ​​uncertainly using the concepts of statistics and probabilities. The simulation of a progressive failure is definite or non-deterministic only by applying numerical techniques such as finite element method that are able to simulate the development of deviant plastic strain. Although the finite element method is widely used in the analysis of sustainability issues, however, this approach is based on problems that are essentially related to gridding. In this research, a radial point interpolation method in combination with a random field was used to model the spatial variations of soil resistance properties and slope instability analysis. In order to consider the progressive failure of soil, elastoplastic method has been developed with the Coulomb Moore's behavioral model for applying strain softness. For probabilistic analysis, the random field is also used to determine the cohesion parameters and the friction angle as well as the plastic strain threshold based on their mean values and standard deviation. In order to investigate the application of the point interpolation method with randomized radial functions, a geotechnical earthwork with definite and non-deterministic geometry has been analyzed and its reliability coefficient has been investigated. Based on the analysis of the progressive failure modeling, it is concluded that the actual failure of the soil and the occurrence of continuous displacements occur simultaneously with the formation of a progressive mechanism of soil degradation and the arrival of the slipping path to the ground. In the following, probabilistic distribution functions of the coefficient of reliability were determined by probabilistic analysis and the production of random fields, and then the statistical parameters are calculated.