Gymnasium roof steel structure

1. Project Overview
Yunnan Minzu University gymnasium construction area of about 7053 square meters, lifting height: the highest elevation +30.720 m, the lowest elevation +18.374m; Structure: tube truss and “H” steel connection.

2 Construction difficulties
2.1 Novel design and unique structural form
The steel structure roof of the stadium is two sloping roofs, and the plane layout is octagonal. It is composed of four space tube trusses with main truss spans of 78.9m and 57.3m respectively, and the member numbers are SHJA(43 t) and SHJB (28 t) respectively. The section of the truss is an inverted triangle, which adopts a pipe-beam-pipe intersecting connection. The material is Q345-B. Four trusses of pipe trusses are installed horizontally on the support of the ring beam, and the upper h-beam is used as the fulcrum. Unequal triangle tube truss, the external section size side length is 5 200 mmX4 293 mmX3 149 mm. Winding steel tube +219X12, a total of 2; The lower string adopts steel pipe 273X16, a total of 1. SHJA component mass 43 t, total length 98m, SHJB component mass 28 t, total length 71 m, the roof steel structure is designed on the ring beam support, the roof through the continuous beam, high-frequency welding H-type light purlin, tie rod connected as a whole, the roof adopts composite profile steel plate and skylight composition.

2.2 Construction difficulties
1) It is difficult to transport the production site to the installation site. The installation site is about 20km away from the production site, and a railway culvert is passed on the way, with a height limit of 4m. The segmental length of the component transport unit is 16~20 m. Because the volume is large, it is difficult to transport by car.
2) The whole steel roof structure is lightweight, its overall stiffness, and overall stability are poor, and stress and strain are difficult to control.
3) The upper chord and supporting column of the inverted triangle pipe truss are hinged, which is difficult to control its stiffness and stability and easy to produce instability.