Özet:
Metro stations and tunnels are some of the crucial infrastructure systems for modern
everyday life in big cities. Considering the seismic vulnerability of megacities such
as Istanbul, the dynamic interaction effects on surface structures due to existence
of these kind of underground structures are not thoroughly investigated. The aim
of this thesis is to investigate the above mentioned interaction problem, i.e. the
dynamic interaction effects on a surface structure due to existence of an underground
structure. For this purpose two dimensional numerical models which utilizes Finite
Element Method are generated and dynamic time history analyses are performed.
Material non-linearity is only considered for the soil domain and the surface structure
and underground structure are modelled as linear-elastic. The surface structure
is modelled as a Single Degree of Freedom system with a mat foundation lying
on the soil deposit. The underground structure is modelled as a frame structure
which is embedded in the soil deposit. A Ricker wavelet with 1 Hz dominant
frequency is used as input motion acceleration history for the numerical analyses.
There are totally 3528 numerical models which correspond to combinations of seven
different case parameters. The case parameters are; input motion amplitude, soil
layer properties, underground structure depth ratio, underground structure height,
underground structure wall thickness, surface structure lateral distance ratio and
surface structure fundamental period. The numerical analyses results include surface
structure acceleration and drift responses along with spectral responses of ground
surface accelerations. Additionally, importance order for the case parameters are
obtained by an Artificial Neural Network based sensitivity analysis. This thesis reveals
that directly including the surface structure in the numerical model yields higher
amplifications in the responses due to existence of underground structure. The surface
structure responses may amplify or de-amplify depending on the distance between the
surface structure and the underground structure.
