1st Croatian Conference on Earthquake Engineering 1CroCEE 2021

Effective and efficient modeling of soil media is of importance in geotechnical earthquake engineering especially when pore pressure development is considered. Concerning the formulation of the coupled approach, a soil element is presented as a mixture of three constituents – soil grains, water and air in the pores. For the mathematical description of the coupled approach mixture theory is considered including the concept of volume fractions. In application of the model the behavior of an earth dam of a trapezoidal cross section is numerically simulated. The simulation is done starting from a specified initial degree of water saturation in the dam body. The simulation considers a nonlinear behavior with respect to the water retention curves and material model for the solid state. The air pressure is assumed to stay atmospheric in the course of the calculation and matric suction is equal to a negative value of the hydrostatic stress in water pressure. The coupled model allows to take into account the deformations of the soil skeleton and simultaneously considers the pore water pressure change during the earthquake excitation of the earth dam. The distribution of hydrostatic water pressures at steady state conditions is compared with results from literature which prove the correctness of the coupled approach. The seismic behavior of the dam body gives interesting results considering both deformation and pore water pressure development.