Design of Single-Layer Cable Net for Xiatian Stadium

Xiatian Sports Park Stadium is located in Dehua County, Quanzhou City, Fujian Province. Its structure consists of a reinforced concrete frame stand in the lower part and a single-layer cable net in the upper part. The single-layer cable net is in a saddle-shaped hyperboloid form, the bearing cables which are concave downwards are arranged along the successive directions of the stand, the wind-resistant cables which are convex upwards are arranged along the left and right directions of the stand, the bearing cables and the wind-resistant cables are mutually connected through cable clamps, and the anti-slip capability of the cable clamps ensures that the bearing cables and the wind-resistant cables do not slip at the intersection positions. The upper single-layer cable net adopts a rigid and flexible mixed boundary constraint form. A rigid boundary is a floor-type steel arch support on a steel inclined column above that stand, and a flexible boundary is compose of a hoop cable supported on a steel mast in front of the stand and side cables supported on the steel mast and a foundation at two side of the stand. The bearing cable and the wind-resistant cable are arranged orthogonally on the projection plane, and the spacing in the projection direction is about 7 m. Because the single-layer cable net is a fully flexible structural system, the structural stiffness is zero and can not bear any load before the prestress is applied. Therefore, the form-finding analysis of the cable net must be carried out according to the expected shape of the building before the calculation and analysis of the cable net. The shape of the cable net and the initial stress state are determined by the form-finding of the cable net, and the cable net with the initial stress state has the ability to bear the external load. After the form-finding analysis of the cable net is completed, the static calculation, the small earthquake elastic calculation and the large earthquake elastic-plastic calculation of the cable net can be carried out according to different loads and action conditions. Through several rounds of optimization and calculation, the boundary conditions and three-dimensional shape of the flexible cable net are determined, and by using the basic principles of the force density method and the extended force density method, the basic program for the form-finding of the complex cable net is compiled and finally used in this project with good results; The bearing capacity and deformation of key joints are checked by three-dimensional finite element analysis and anti-slip test. The above analysis results show that the structural selection of the single-layer cable net of this project is basically reasonable, and the design results meet the requirements of the current national specifications.