Fine Construction Control Method Study Of Asymmetric Self-anchored Suspension Bridge With Single Tower

Self-anchored suspension bridge is a special type of bridge with beautiful structural shape,good economic performance,strong adaptability to geographical conditions and other characteristics,and has gradually become a priority for the construction of engineering.In terms of force,self-anchored suspension bridge directly anchors the main cable on the main beam,which not only makes the main beam bend,but also bears the axial force component brought by the main cable,which is equivalent to providing free prestress and saving a lot of cost.But the self-anchored suspension bridge is different from the ground anchored suspension bridge,and the construction procedure is restricted.After the construction of the main tower and girder,the main cable can be towed,the sling can be installed,and the system transformation can be completed.As it is a cable system,the non-linearity is very prominent.Therefore,it is a difficult point in the construction control of this type of bridge to adopt reasonable construction steps and complete the reasonable force of tower beam and cable according to the established scheme.In this paper,a single tower non-symmetric self-anchored suspension cable is combined with three methods to compare and verify the cable shape of the whole bridge,and then the influence of different cable saddle simulation methods on the stress-free length of the main cable is studied.Then the cable saddle is simulated by the finite element method and the time and amount of the cable saddle pushing are found out.Finally,hanger tensioning of the bridge system is optimized to achieve the formal simulation of the whole bridge.The specific research content is divided into the following aspects:(1)In this paper,parabola method,piecewise catenary method and nodal method are used to compare and analyze the alignment of the main cable under the bridge and the cable,and the construction error is analyzed by using the above theory.(2)Through the optimization analysis of the part of the main cable saddle,the non-stress length of the main cable at the main cable saddle can be accurately corrected by simulating the boundary conditions,stress states and geometric characteristics of the main cable saddle.(3)In the process of system transformation,jacking is required for the safety of the main tower,when and how much jacking is required,and simulation analysis is required.Therefore,finite element analysis is adopted in this paper to calculate the jacking time and amount of the main cable saddle and analyze the deviation of the main tower in the jacking process.(4)For each component,such as the length of anchor holes in the beam,the elevation of the main tower,due to manufacturing errors,construction errors will be deviated from the design theory,so if only the theory into the state of the bridge to do system transformation scheme will lead to the actual deviation,the scheme is not allowed.Therefore,adopting effective hanger tensioning scheme is also the focus of this paper.