Optimal distribution of piles under a concrete bridge abutment subject to vertical and torsion loads

The transmission of torsional load from the bridge abutment to the pile foundation has a great influence on the behavior of piles The situation is worsened by the combined loading on the outriggers, such as torsion, vertical, and lateral loads. This study focuses on the importance of distributing the piles under bridge abutment subjected to torsion loads in addition to vertical loads, where a suitable distribution is found to provide better behavior of the piles. Four groups of piles were taken under the bridge abutment, each containing six piles with different distributions. Torsional and vertical loads were applied to the bridge abutment to ensure the transfer of loads with a realistic effect. ABAQUS software was used for the simulation after the experimental work. The results of different pile distributions were very from the design point of view, as it was found that the distribution of the piles under the bridge abutment must be in a multi-line shape (rectangular distribution of the piles), because it forms a rigid mass with the surrounding soil, which is able to withstand torsional loads. In addition, it is preferable to avoid using single-distributed piles, since their response is very high and the failure occurs faster than in other groups.