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Soil-pile-structure interaction (SPSI) plays an important role in assessing the vibrations internally generated within structures due to dynamic loads that could bring significant impacts on structural behavior. In this study, the effects of (SPSI) forces on the seismic response of three tall and massive building cases were investigated. The emergency hospital building is an existing reinforced concrete construction with concrete columns. Due to the importance of the building and its potential danger in failure cases of the load-bearing structure, earthquake analysis was first carried out by using a 3D finite-element model for the entire structure and FCONE program for the soil under the structure. This program utilizes the equivalent dynamic modeling concept in the analysis of soil dynamics and pile-foundation interaction. The implementation of simulation was conducted in two different conditions: namely, fixed-base behavior and soil-structure interaction are considered. In this case, soil-structure interaction is considered by assigning equivalent springs and dashpots located under foundation, and the analyses were carried out directly in the time domain for considering the effects of interaction. It is shown that the effects of soil-structure interaction are demonstrated as increasing the period of vibrations and the displacements. Based on the results obtained by using CONE method, the period of vibration in the case of concentrated piles with the correction factor for pile-group action, exhibiting the value of (1.2 s), which is increased up to 42% compared with the case of fixed base (0.7 s). Similar results were obtained for seismic analysis of two other cases. It has shown that the first period of vibration in the case of Silo project and MIT Science Building increased by about 74% (from 1.72 s to 3 s) and 11% (from 1.37 s to 1.53 s) with respect to the SPSI effect, respectively. Besides, a comparison was made between the structural responses of the obtained CONE method and 3D finite-element simulation in ABAQUS which indicated that these results were in good agreement with direct results. It was concluded that CONE model as a convenient, fast, and rather accurate method can be applied for foundation vibration and dynamic soil-structure interaction analysis in a practical engineering projects whenever possible. |
