چكيده به لاتين
The analysis of structures subject to earthquake ground motions must properly account for the interaction between the foundation and the superstructure. As the seismic shear wave propagates through the soil deposit, the embedded foundation tends to modify the transmitted excitation due to the soil–foundation stiffness contrast, the boundary constrains of the head and tip of the pile as well as the dynamic response of the system. This interaction develops even in the absence of a superstructure and is referred to as the kinematic interaction. Its effects on the ground motion are described by a function termed the transfer function. At the same time, the dynamic response of the superstructure itself induces additional deformations to the pile and the near-field soil. This effect is known as inertial interaction and is captured by representing the foundation through and impedance function.
In the present thesis, the effects of kinematic interaction on the seismic response of single piles and pile groups have been investigated by physical modeling, performed by 1g shaking table tests and numerical simulations. First, a series of 1g reduced-scale shaking table tests were conducted at Geotechnical Research Center, Tehran University (GRC-TU) to study the seismic behavior of single piles and pile groups and the results of these tests were used to verify numerical modeling. Then, the numerical model of the experiments was utilized to perform an extensive parametric studies.
It was concluded that the internal forces and displacements along the pile length mainly controlled by: soil profile type, relative stiffness, slenderness ratio, shape, fixity conditions of pile head, soil-pile separation and intensity of input motion parameters. Therefore, evaluation the effect of these parameters on internal forces and displacements along the pile length are recommended in seismic design.
Keywords: Kinematic interaction, Pile foundation, Seismic response, Physical modeling, Shaking table, Numerical simulation.
