An analytical approach to torsionally coupled seismic response of eccentric structure incorporating soil-structure interaction

An analytical approach based on branch mode method is formulated in this paper to study the dynamic response of eccentric structure considering soil-structure interaction The superstructure branch and foundation soil branch are coupled through mode aggregation procedure. The computational scale of system equations decreases to an acceptable level. Sample analysis indicate that the seismic response of eccentric structure increases first and then decreases with the decreasing of stiffness of soil-foundation system, which is affected by the inertia effect of foundation branch. For the soft soil case, the influence of SSI effect is more intensive that the trends of transfer function curves are fundamentally changed comparing to the results of other foundation conditions.