3 Legged Angular Steel Towers

3 Legged Angular Steel Towers

The transmission line selfsupporting Angle steel tower can be divided into three parts: tower head, tower body and tower leg. The tower head is used to suspend wire, ground wire and jumper, and meet various electrical function parameters; The tower body is used to extend the scale of the vertical direction of the tower, in order to meet the role of crossing obstacles, the tower leg is the tower and foundation foundation connection, and applicable to a variety of terrain slope part, is the tower can be stable based on the fundamental, is the foundation of the tower.

Therefore, the planning of the tower legs is a crucial part of the safety and environmental friendliness of the tower.

The main principles of Angle tower leg planning

(1) The mountain tower shall be calculated according to the all-round long and short legs, and set according to the 30° topographic slope of the tower legs (30° front). The range shall be increased as far as possible to meet the requirements of the mountain terrain under the condition of reasonable structure layout;

(2) The maximum thigh length should be controlled within 20.0m, and the maximum thigh length such as the span tower can be appropriately enlarged;

(3) The pant transition structure can be used to make different call height with the same set of legs to reduce the amount of drawing, but UHV tower and heavy ice tower is not recommended to use;

(4) In order to ensure that the tower has enough torsional stiffness, the tower leg and the tower body should be set up at the section.

(5) The basic difference of the tower leg is generally considered by 1.0m, and for the big root opening tower, it can also be considered by 1.5m;

(6) The slenderness ratio of leg inclined timber, the magnification factor of 1.2 should be considered according to the specification requirements;

(7) The included Angle of the main inclined material of the Angle steel tower leg should not be less than 18° (not less than 20° in the heavy ice area), and the included Angle between the inclined material of the tower leg and the horizontal plane should not be less than 25° (it is recommended that the Angle should not be less than 30°);

(8) When the Angle of the loading material at the end of the Angle steel tower leg is small, the auxiliary material supporting the loading material should be properly strengthened. Generally, when the Angle of the main inclined material of the tower leg is less than 25°, the bearing capacity of the auxiliary material supporting the bearing material should be checked according to the first 1-2 auxiliary material nodes supporting the main material 2.5% internal force;

(9) The auxiliary materials of the tower leg should be arranged in a reasonable way to enhance the supporting effect of the main and inclined materials. The diagonal stiffness of tower leg should match that of main wood. Appropriate matching can be carried out according to area, limb width (or line stiffness), etc.