Fully-assembled staircase system and assembly method

An assembly method for a fully-assembled staircase system, comprising:

• 1) installation of a stair slab LTB, stair stringers TL, and landing slabs PB:
• lifting and conveying the stair slab LTB, the stair stringer TL, and the landing slab PB to the same elevation, first placing steel connectors GLJ in first grooves (1), third grooves (23), and second grooves (13) at joints between the three components, and then connecting and fixing the stair slab LTB, the stair stringer TL, and the landing slab PB by bolts and bolt holes;
• 2) installation of steps:
• installing the steps from bottom to top sequentially, wherein all the steps are standard stair steps TB except that the last step is a top stair step TB1;
• inserting a front toe (7) on the first standard step into a sill (22) at a lap joint at a lower end of the stair slab LTB, and inserting a protruding bayonet (6) in the middle of the sill (22) into an engagement groove (8) at a bottom in the front of the step;
• and pressing, by using a front toe (7) disposed at a bottom in the front of the second step, a rear toe (12) disposed at a rear of the first step, inserting a bayonet (11) disposed at the rear of the first step into an engagement groove (8) provided in the front of the second step, and assembling other steps according to the same assembly method;
• 3) assembly of stair handrail steel posts GLZ:
• first inserting a rectangular tenon (18) at a lower end of the steel post into a slot (20) provided on a side surface of a step, and then fixedly connecting a stair-slab connecting portion under the rectangular tenon (18) to a side surface of the stair slab to tightly connect the step, the stair slab, and the steel post;
• and
• 4) installation of stair handrail panels GLB:
• connecting stair-handrail-panel connecting portions of the handrail panel GLB to stair-handrail-steel-post connecting portions of the steel posts GLZ in a one-to-one correspondence;
• and connecting the stair slab LTB to the stair step by a fastener at a position at which the handrail is not disposed.