Home – Home – Jornals – Russian Geology and Geophysics 2018 number Неопубликованное

Within the framework of the elastic-plastic model of the behavior of the medium, the influence of the non-uniform distribution of properties and the geometry of the problem on the stress-strain state of a 500 km thick block model under the action of gravity is considered. Calculations were carried out in a 2D formulation of a plane stress state for a rectangular and cylindrical profile, taking into account the curvature of the Earth's surface. It is shown that anomalies in the stress-strain state and zones of development of irreversible deformation are determined primarily by the heterogeneity of the structure, the presence of density and rheological anomalies. The geometry of the models, taking into account the curvature of the lithosphere significantly affects primarily the stress state in the crust, where the greatest shear strength is, which determines the development of irreversible deformation depending on the heterogeneity of the medium.
In this work, to assess the influence of the geometric factor on the stress-strain state of the lithosphere, numerical modeling of its seismic model along the Craton profile, 3600 km long and 500 km deep, presented in rectangular and cylindrical coordinates, was carried out. A comparison of the obtained solutions was carried out.
The change in the stress-strain state during the rise and immersion of a block of the medium with a cylindrical formulation of the problem is considered. It is shown that vertical displacements with such a formulation have a noticeable effect on horizontal stresses and can lead to the development of irreversible deformation.
It is shown that with successive layer-by-layer build-up of the crust, the deviation of tangential stresses in a cylindrical setting from horizontal stresses of a flat model at the surface is negligibly small. The maximum deviation occurs at the middle of the depth of the deformed layer.