There is aerodynamic interference effect between spire-type main cable and catwalk of a long-span suspension bridges during construction.Studies have shown that the main cable is easy to occur galloping instability and catwalk is prone to occur static wind instability.In order to ensure the stability of main cable and catwalk during construction

the spire-type main cable and catwalk of a long-span suspension bridge under different working conditions during construction are selected as the research object.The setting method of catwalk parameters which can ensure galloping stability of main cable during construction is used.And the method of numerical simulation with CFD software FLUENT and finite element software ANSYS are used to study the three-component coefficients and static wind stability of catwalk during construction of spire-type main cable.The results indicate that the spire-type main cable in different construction conditions has a greater influence on the catway.With the construction of spire-type main cable

the critical wind velocity of instability reduces

and then it will increase.Different construction sequence of spire-type main cable can affect both galloping performance of main cable and wind stability of catwalk during construction

both of those should be comprehensively considered during construction.