Stadium stand space frame canopy

 1Project overview

Jordan Hassan Sports City is a large sports center consisting of gymnasiums, training halls, sports fields, swimming pools, and other sports facilities. The plane of the sports field is oval, with two stands in the east and west. The stand is 136m long and 32m wide, Stadium stands with a space frame canopy with three floors of seats and a walkway in the middle. Set a distance over the West Stand. Due to the influence of the Mediterranean climate, the wind was strong and the basic wind pressure was 0.8KN/m, so the design of the canopy was complicated. The platform and section of the canopy are shown in Fig. The sports field can be used for track and field and football games and can accommodate 15,000 spectators.

2 Several common practices of steel canopy

The cantilever is a large-span cantilever structure, which is greatly affected by the wind and can withstand upward suction or downward pressure. The original method is generally a concrete structure or a pipe-through space frame. When the canopy is wide, the size of the concrete or space frame components is quite large, which is very bulky and affects the sight of the audience in the back row. Due to the light weight of the space frame structure and the convenience of on-site installation, the general canopy now basically adopts the space frame structure. The following are several common canopy forms.

A curved space frame with no fulcrum in the middle is used. For example, the football track and field of the 13th Mediterranean Games built-in Split, Yugoslavia, is set at both ends of the arc. The canopy adopts a crescent-shaped bolt ball node space frame without a fulcrum in the middle, which looks very grand and social. However, this kind of curved space frame has a wide variety of rods, and the angle of the node ball is complex, so it should be processed by CNC machine tools. At present, the processing level of domestic space frames cannot meet the requirements.

space frame canopy

2 using a flat space frame.

A fulcrum can be set in the middle of the space frame, and a tie rod can be set at the rear. It is also possible to have no fulcrum in the middle, but the rear of the stand and the canopy are all framed. form a whole.

The plan for the canopy of the stadium in the Hassan Sports City in Jordan has been confirmed

The canopy adopts a flat bolt ball joint space frame. The net erection slope is 14%. The front part is bent, the rear part is supported on the reinforced concrete beam, and a steel pipe column with a diameter of 500mm is set every 8m in the middle. The entire canopy construction space frame is 128m long and 32m wide. Two expansion joints are set. Divide the space frame into three shots along the length. It becomes 48+32+48. A landing zone is set at both ends of each space frame to resist the lateral wind force and the lateral ground recovery force. The space frame size of the space frame is 2.667×2.667, and the thickness of the front exaggerated part is 1.49m with a thickness of 2.371.

3 Steel Structure Canopy designs

3.1 Determination of wind carrier shape coefficient

For the space frame canopy structure, the wind load is the main road, so the value of the body shape coefficient is very important to the safety of the canopy, and it should be determined through wind tunnel tile inspection. Due to the lack of wind tunnel test data in the design, and such a large-span canopy has not been done in China, there are few foreign data. In this case, the Chinese, British, and West German codes were analyzed and compared during the design, and it was believed that the value of the wind carrier type coefficient of the national gauge bubbles was relatively safe, that is, the downward pressure was +0.5. The upward suction coupling -1.3. At the same time, the influence of wind vibration on the canopy is also considered, and the wind vibration coefficient is B=1.5. There is no crosswind in the Chinese code. In order to ensure the safety of the structure, the crosswind in the British code is used in the design. The body shape factor is ±1.0.2. The attack plan of the net Zhu rod is forced because the lower part has a protective structure. Therefore, under the action of wind and k, a great upward suction force is generated.

3.2 Support conditions and supports

Support conditions should be assumed based on the form and stiffness of the substructure. The sophisticated method should consider the substructure and mesh as a recent calculation, but the work disk is too large to do so. And it needs a large-scale computing machine. In the design of the peach space frame in the sports field, in order to simplify the calculation, the substructure is assumed to be elastic support. Using the pillars as bullets outside the plane basically solved this problem. Generally, the support of the space frame is under pressure, so the pressure support can be designed. However, the support of the canopy net frame may be exposed or pulled. Therefore, when designing the support, not only the pressure support should be designed.