Analysis And Calculation Of Main Cable Curve For Self-anchored Suspension Bridge

As the traffic constructions of China develop in these years,Along with the increase of the spans of suspension bridges,the influence with geometric nonlinear character gets more and more notable.the ratio of width to span has decreased,but the width of bridges is limited.So horizontal stiffness of bridge is decreased.It is necessary for designers to design reasonable system of suspension bridge to improve the whole stiffnessthe,spatial calbe suspension bridge is three spatial system with the cables.The Horizontal loading of the cable can be improved,with not affection the perpendicular loading.The whole horizontal and twist stiffness of bridge will be improved.The segmental catenary theory in the planar system has been perfect.Calculation theory of spatial suspension bridge is dedused under the calculation theory in the plan system. Take the Liede bridge for example,the Concrete calculation analysis is deduced.The main contents about of this thesis are as follows:(1).Based on the segmental catenary theory in the planar system,the segmental catenary theory in the spatial system is deduced.With the Newton-Raphson iterating method,two kinds of numerical analysis method for cable is analysed,which solution of span with the cable force and span,and solution of cable force with the span,high Margin and cable length.(2).Based on the segmental catenary theory,It is Target to Establish the linetupe for suspension bridge,The basic principles which should be followed in the structural calculation of suspension are elaborated in details,in which the correction calculation of the main cable on saddle's position is generalized into the separate calculation method and the iterating approached calculation method. Two conception of saddle of suspension bridge which are defined as one of level busbar and the one of tilt busbar are presented. Based on the saddle's theoretical apex which is defined as extensive catenary crossing point.The method of tilt busbar saddle's position is explored greatly.The eleven nonlinear equations are derived from mechanical relationship and geometrical relationship , which are solved by the Newton-Raphson iterating method.The step and iterating method are introduced.The Jacobian Matrix is deduced,the method which iterative initial value be defined is put forward.Improving the constraint condition,which ensures the iteration quickly to converge at the true solution. Calculation method on the unstressed length of cable on the saddle is also deduced.(3).Based on the segmental catenary theory,linetype change stiffness of cable are deduced.The calculation linetype theory for suspension bridge is established on free cable state and design state.The program is compiled on calculation of cable for suspension bridge in free cable state and design state.Based on the Liede bridge,the calculation analysis is presented.