290HC Mast Section construction ensure the safe and reliable laying of tower crane subgrade and track
1. The laying of tower crane subgrade and track must be carried out in strict accordance with the specifications. In general, the bearing capacity of subgrade soil: medium tower (3-15t) 0.12-0.16mpa; heavy tower (above 15t) ＞ 0.2MPa. It shall be repaired, leveled and compacted with sand, ballast and drainage measures.
2. Timber, reinforced concrete or steel sleepers can be used as sleeper materials. The section size shall be in accordance with the specification (such as 16 × 240, 180 × 260, etc.), and the sleeper length shall be at least 1200mm larger than the track gauge size. When a long sleeper and two short sleepers are used for arrangement, a channel steel tie rod shall be added every 6m or so to ensure the gauge. Sleeper spacing is 600mm. When the shaped subgrade box is used, it shall be checked and accepted before use to confirm that it meets the requirements.
3. Both sides of the track shall be nailed firmly (or pressed firmly by pressing plate) on each sleeper without missing or loosening. The joints of the track shall be staggered, the joints shall be set on the sleepers, the height difference between the two ends shall not be more than 2mm, the joint clamp plate shall be matched with the track, and all bolts shall be filled and fastened.
4. The horizontal deviation of the track shall not be greater than 1 / 1000 in the vertical and horizontal directions. (level gauge shall be used to measure the average value of two tracks within 10 m, which are less than three points respectively).
5. A limit position stopper (stopper) shall be set at the place 1m from the track terminal, and its height shall be greater than the radius of the traveling wheel to prevent the tower crane sliding after power failure from derailing.
6. The foundation construction of the fixed tower crane shall be carried out according to the design drawings, and its design calculation and construction details shall be included in one of the special construction organization design contents of the tower crane, which shall be accepted and recorded after construction.
