Foundation for a tower of a wind-turbine

A method of constructing a foundation, the method comprising:

• forming first, second and third vertical holes in the ground, each of the first second and third vertical holes having a depth;
• inserting a first, second and third main reinforcement respectively inside each of the first, second and third vertical holes, each of the first, second and third main reinforcements being formed by a plurality of horizontal rings and a plurality of vertical bars attached to one another forming respective first, second and the third cylindrical frameworks that respectively extend around a contour of the first, second and third vertical holes, each of the first, second and third main reinforcements having a length that extends along an entire depth of the respective first, second and third vertical holes;
• installing a first, second and third bolt cage inside an upper portion of the respective first, second and third main reinforcements, each of the first, second and third bolt cages respectively including a first, second and third upper collar, the first, second and third bolt cages being arranged such that each of the first, second and third upper collars protrude from a level of the ground;
• with the use of first, second and third leveling elements extending between the first, second and third upper collars and arranged 60 degrees from one another, arranging the first second and third bolt cages so that the first, second and third upper collars are level with one another;
• and
• after the first, second and third upper collars are level with one another, pouring concrete into each of the first, second and third vertical holes to encase the first, second and third main reinforcement and first, second and third bolt cage inside the respective first, second and third vertical holes.