DESIGN AND RESEARCH ON STATIC LOAD TEST OF A BIDIRECTIONAL BEAM STRING STRUCTURE AFTER CABLE SHAPE OPTIMIZATION

Equilibrium load value determines the shape of a bidirectional beam string structure. Static load test of an experimental bidirectional beam string structure model after cable shape optimization is designed. The node of brace and the chord of upper steel beam are stimulated by the universal coupling. Wreaths screwdriver is used to stimulate the tensioning end and modified U type rode cappel is used to stimulate the anchor end. A loading scheme combining lever concentrated loading by multi-point distributive beam and center loading is adopted. The experimental results show that the forces of each cable in two directions are almost equal and evenly distributed when the vertical load value increases to the equilibrium load value after cable shape optimization. The cable force distribution will be adjusted during the loading stage. The cable of bidirectional beam sting structure is susceptible to the asymmetrical live loads, especially to the half span load. Compared with the whole span uniform load, a half span uniform load probably lead to greater forces in the side span cables of the bidirectional beam string structure.