Effect of Soil-Pile-Structure Interaction on Seismic Design of Tall and Massive Buildings Through Case Studies

摘要

In this study, the effects of Soil-Pile-Structure Interaction (SPSI) forces on the seismic response of two tall and massive building projects were investigated. The first case study is an emergency hospital building located in south of Switzerland which 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, seismic analysis was first carried out by using a 3D finite element model for the entire structure and a new FORTRAN program based on the enhanced cone model for the soil under the structure. The implementation of simulation was conducted in two different conditions, namely fixed-base behavior and soil-structure interaction, which are considered. Based on the results obtained by using the cone frustum approach, 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), is increased up to 42% compared with the case of fixed-base (0.7 s). In the second phase, the dynamic responses of the Green Building at the MIT campus in Cambridge during three ground motions were studied through both approaches. It has shown that the first period of vibration in the case of the MIT Science building increased by about 11% (from 1.37 to 1.53 s) with respect to the SPSI effect. 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 the direct results. It was concluded that the enhanced cone model as a convenient, fast, and rather accurate method can be applied for foundation vibration and dynamic soil-structure interaction analysis in practical engineering projects whenever possible.