Investigation of the Arrangement of Energy Pile Groups Under Thermal and Thermo-mechanical Loading

The arrangement of energy piles in a group is an important and complicated topic that requires extensive study and research to provide reliable results. In this regard, a series of small-scale physical models were conducted in Babolsar sand. The first single energy pile and the second 3 x 3 pile group were performed with four different energy pile arrangements in the group. Different operating modes of energy pile were done symmetrically and nonsymmetrically with different distances. The results showed that the average thermal displacement of the pile cap of the symmetric was more than nonsymmetric ones, under completely similar conditions. Also, with the distance increase between the energy piles in the group, the average thermal displacement decreased by about 25%. In addition, the pile group's thermal expansion values may be larger than the single pile. Also, it was observed that the maximum axial force of the pile in the positions of different piles in the group may be lower than that of the single pile. Such behavior can be seen by increasing the number of energy piles in the group (depending on the position of their implementation).