Dynamic Response of Frame Structure System Considering SSI Effect

A 1∶6 ratio frame structure model was designed for shaking table test, in order to study the influence mechanism of soil-structure interaction on the dynamic displacement response of high-rise structures on soft soil foundation. Shaking table tests were performed on a high-rise frame structure considering soil-pile-structure dynamic interaction system and on a frame structure model on fixed-base condition. By comparing the structural dynamic response of the frame models considering the soil-structure interaction (SSI) and the fixed-base condition, the influence of the SSI effect on the high-level frame structure in this experiment was summarized: after considering the SSI effect, pile-soil interaction has an obvious filtering effect on seismic waves; in a large earthquake, the peak is generally weakened, and the vibration frequency of the overall structure is reduced, and the damping ratio is increased. From the perspective of structural internal forces, the SSI effect reduces the floor shear force and bending moment, and effectively reduces the impact of ground vibration on the structure. From the perspective of structural displacement, when the magnitude is small, the SSI effect reduces the elastic displacement and interlayer displacement angle of the structure, and reduces the effect of the earthquake on the structure; when the magnitude is larger, the upper floor increases the structural displacement response due to model differences and damage accumulation under some working conditions. From the perspective of structural acceleration, the SSI effect reduces the absolute acceleration and relative acceleration of the floor, and also reduces the effect of earthquakes on the structure. This is due to the radiation damping and hysteresis damping generated by soil-pile-structure interaction under the SSI effect dissipate the energy of the entire structure-pile-soil system, while the radiation waves transmitted by the soft soil foundation to the superstructure change the dynamic characteristics of the structure.