The stress-strain state investigation of underground structures on the basis of soil models with adjusted input parameters

The article evaluates the possibility of using Hardening Soil Model and Coulomb-Mohr soil models with corrected input parameters by investigating the stress-strain state (SSS) of underground structures. Today there are many different mathematical models of soil: Coulomb-Mohr, Hardening Soil Model and its derivatives (Hardening Soil Small-strain), Soft Soil and its derivatives, Cam-Clay, etc. They are characterized by the varying degrees of complexity and the range of use. In geotechnical practice, the simplest perfectly elastic-plastic soil model of Coulomb-Mohr is used very often for calculations, but having several disadvantages. Hardening Soil Model is an advanced nonlinear soil model which is versatile and suitable for modeling a wide range of soil bases. The features of the model include the use of a nonlinear relationship between strains and stresses, the separation of shear and bulk components of deformation, a separate trajectory of deformation during unloading-reloading, the dependence of deformation characteristics on the level of stresses at the base, etc. However, the large number of input parameters, which are not verified by some regulations, makes it difficult to use. The influence on the magnitude and nature of the distribution of the stress-strain state of underground structures using the Hardening Soil model with the corrected parameters obtained using empirical formulas is analyzed. Also the question is relevant regarding the usage of the Coulomb-Mohr method with the extension of the methods (different options for deformation of the module with depth, using Eur deformation module during loading and reloading), it may be possible to reduce the number of inaccessible issues in order to inflict on the deformed condition of underground structures.