This paper contains several investigations on the behavior of bulged piles. Bulge means the application of vertical steel plates somewhere near the ground surface to improve the lateral bearing capacity. The results of small scale tests in sand are illustrated, which demonstrate the effectiveness of such bulge. Some theoretical investigations are presented trying to apply standard methods like the -curve procedure to the design of bulged piles. An outline of possible calculation methods is given. Investigations on two different exemplary pile systems demonstrate the behavior of the bulged structure and give an idea of the advantages of this innovative system.