Investigation of cushion layer in terms of structure-soil interaction in high-rise buildings with piled raft foundations

The fact that the majority of our country is on fault lines causes the effects of earthquakes to be high. In order to reduce these effects, piles are used in the foundation of the structure in soft soils. In recent years, the cushion element used in pile raft manufacturing affects the behaviour of the pile and the structure. This study investigated pile, foundation and building behaviour during the structure-soil interaction when the pile and raft connection is interrupted by the cushion element. Superstructure, foundation and soil are modelled in SAP2000. In the region with soil class ZD, the 1999 Düzce earthquake loads were used and the analysis was performed in the time history in SAP2000. According to the results of the analysis performed on two different applications, basically connected and unconnected, it has been observed that the displacements in the structure are less than 20% in case of cushion use. It has increased the bearing capacity of the structure on soft soil. In the use of cushion, the loads acting on the piles decreased and the amount of settlements decreased by 8%. It was determined that the difference between different settlements was 1 cm less in the case of using cushion.