Method for stretching single-tower double-span self-anchored suspension bridge sling of side-span splay cable knot in supportless way

The invention discloses a method for stretching a single-tower double-span self-anchored suspension bridge sling of a side-span splay cable knot in a supportless way. The method is characterized by comprising the following steps of: alternately stretching slings at lateral span sides when a main-span sling is gradually stretched from a main tower to a splay cable saddle at a main tower side; firstly stretching a BK-M sling close to a splay cable knot at a lateral span side; then, sequentially and gradually stretching to the side-span splay cable knot; and sequentially and gradually stretchingfrom the BK-M sling to the main tower and upwards pushing a main cable saddle if the deviation of a tower top exceeds a limit in the process. In the method, the characteristic of greater control sling force of a permanent sling close to the side-span splay cable knot is utilized, the vertical displacement of the splay cable knot can be basically controlled after the permanent sling is stretched, the sling force has little