Construction method for door opening with arc-shaped chamfer at double-curved-surface stair handrail

The invention discloses a construction method of a door opening with arc-shaped chamfers at a hyperboloid stair handrail, the stair handrail is a continuous hyperboloid arc formed from inside to outside from low to high, external corners on two sides of the top of the stair handrail are arc-shaped chamfers, one end of the top of the door opening is an arc-shaped corner, the other end of the top of the door opening is a right angle, and the inner side of the door opening is an arc-shaped chamfer. The method comprises the following steps that firstly, a template is subjected to BIM modeling; step 2, deepening the template BIM model; step 3, template processing; fourthly, the handrail formworks are spliced; step 5, reinforcing the handrail template; sixthly, door opening formworks are spliced; seventhly, layered and segmented pouring is conducted; 8, the formwork is removed; ninthly, the formwork is repaired; tenthly, relevant parts are maintained; and step 11, concrete surface curing. According to the construct