The invention provides a manufacturing method of a small-spacing three-web box beam, which comprises the following steps of: S1, blanking and
processing:
cutting by adopting a
numerical control flame and
plasma cutting technology, blanking at high precision according to a design size, reserving a
machining allowance and a groove form, and
polishing after
cutting; s2, assembling and positioning are conducted, specifically, components are assembled on the jig frame through the upside-down mounting technology, and positioning of a top plate is completed firstly; positioning an inner side web plate and a middle web plate; pre-penetrating positioning of U ribs, longitudinal beams and anchoring partition plates is sequentially completed on the middle web; and finally, positioning of the outer side web is completed. S3, bending position
welding forming is conducted, specifically, a side web and a top plate are welded at a bending position; after flaw detection is qualified, middle webs and a top plate are fixed through downward
welding; u-shaped ribs and longitudinal beams are welded and fixed in a bending manner;
welding a bottom plate, and fixedly connecting the bottom plate with the middle web plate, the anchoring partition plate and the side web plate in a welding manner; finally, the stiffening ribs and the support base plate are welded and anchored; s4,
flame cutting process allowance; and S5, sanding and
coating are conducted, and manufacturing is completed. High-quality welding manufacturing is achieved, and the method is suitable for popularization.