چكيده به لاتين
In this study, numerical modeling of the phenomenon of reverse dip-slip faulting propagation in granular soil and its interaction with the shallow foundation and inclined wall which is used to improve and deflect the rupture path, by using the discrete element method (DEM) with considering Particle rolling resistance has been performed.
The three main parts of the study include propagation of reverse dip-slip faulting in granular soil, reverse dip-slip faulting interaction with shallow foundation and reverse dip-slip faulting interaction with shallow foundation and inclined wall, each of the two engineering and fundamental perspectives studied Is placed. From the engineering perspective, issues such as rupture paths, surface deformation, rupture outcrop strain, rupture outcrop location, and rotation of shallow foundations are investigated. in fundamental perspective, an attempt is made to study and express the formation and deflection of shear bands using micro-parameters and the micro-macro relationship in the formation and deflection of shear bands. It is worth mentioning that in all three sections of the study, the effect of soil density has been studied, and also in two sections of interaction studies, the effect of foundation load on micro and macro results has been studied.
The results of studies with an engineering perspective show that shear bands are not a single rupture but consist of some ruptures that occur at different strains. Also, these rupture paths are not along the straight plane of the fault and due to the density and angle of the fault plane, The rupture is diverted to hanging and footing walls. In the study section of the interaction of reverse faulting and shallow foundation results show that the shallow foundation causes deviation of rupture paths and as the foundation load increases, this deviation also increases, and also with this increase, the rotation of the foundation decreases. In the study of the interaction of reverse faulting, inclined wall, and shallow foundation the results show that the inclined wall causes the rupture path to deviate and decreases the rotation of shallow foundation, and this decrease in rotation increases with increasing the angle of the inclined wall relative to the horizon. The results also show that with increasing wall thickness the anti-clockwise rotation of the shallow foundation increases.
The results of studies with a fundamental perspective show that the reduction of the coordination number is a key event on a micro-scale in that by reducing the coordination number and thus breaking the contact between particles, large cavities begin and as a result, the dilative behavior in the sample begins. This also causes a strong particle rotation gradient in the shear band. It is worth mentioning that the failure mechanism in shear bonds is such that with the application of shear, the number of strong contact forces in the direction of the maximum main stress increases, which causes stiffening behavior in the sample, but while shearing continues because of the tensile strains which occur Due to the effect of rolling between the particles the strong contact forces in the direction of the minimum main stress is lost and with the occurrence of this, the strong force chain that is in the direction of the maximum main stress lose their lateral supports and buckle. As a result, the number of strong contact forces in the direction of the main stress is reduced which causes softening behavior. However, in the study of the interaction of reverse faulting with shallow foundation, the results show that the formation of shear bands and micro-parameters on the ground surface is more affected by the weight of the foundation. and in the study of the interaction of reverse faulting with inclined wall and shallow foundation, in the deeper depth Shear bands formation and micro-parameters are mostly affected by the pressure caused by the inclined wall.
