Dynamic calculation of a plane “Earth Dam-Base” system under seismic impact

Abstract

Design, construction, as well as reliable and safe operation of earthen hydraulic structures (earth dams) in the Republic of Uzbekistan, located in a seismically hazardous zone, require constant improvement of load calculation methods, as required by building codes, including constant loads (static - gravity, hydrostatic) and temporary dynamic loads (seismic). The current normative method does not take into account the non-one-dimensional behavior and piecewise heterogeneity of the soil characteristics of the structure and foundation. It does not allow determining the stress-strain state (SSS) of an earthen dam, which is especially important for reliable and safe operation in seismic areas. A mathematical formulation of the dynamic problem of an earthen dam in a flat elastic formulation is given. The problem is solved numerically by the finite element method. The eigenfrequencies and modes of vibrations of the flat system “structure-foundation” are determined taking into account the piecewise inhomogeneous characteristics of the foundation soil. Based on the results of these parameters, an appropriate behavior analysis is performed. The SSS of the “dam-foundation” system was studied at the calculated natural frequencies. The result of the calculation was the isocline of equal displacements, normal and shear stresses in the “dam-foundation” system.