Open a hole in the original concrete structure to build a cross story staircase, with a cantilever of 8.2 meters, and the side beam of the staircase is only 350 high! The anchoring method is unique and very instructive. The project is designed in strict accordance with the latest national standards, and the drawing is rigorous, and the details are exhaustive. The drawing has passed the review. The drawing adopts 3D model projection and slicing to form dwg drawings with high accuracy. Attached with rhinoceros style stair structure precision mold. MIDAS GEN is adopted for design, and calculation model is attached. It has been completed, with photos of the scene.