A Refined Non-linear Analysis Method For Suspension Bridge With Hybrid Beam And Its Application

On the basis of the segmental catenary theory for shape-finding and nonlinear finite element method, this dissertation comprehensively considered the structural, mechanical and constructional characters of the self-anchored and earth-anchored suspension bridges, and the need for calculation of design and construction incorporating the construction of the PingSheng Bridge, Which is the first self-anchored suspension bridge with single tower and hybrid beams in the world. A series of research work was carried on around the analytical theories, numerical algorithm, program development and application for the suspension bridge with concrete stiff girder. And a program which can satisfy the calculation of design and construction control for various kinds of suspension bridge (which can be simplified into flat structures) was developed.This dissertation was composed of 7 chapters. In the chapter 1, static calculation theory and method for the suspension bridge have been summarized. in the chapter 2 and 3, the method of main cable shape-finding and saddle position calculation was researched. The nonlinear finite element analysis theory and method for the suspension bridge with concrete stiff girder was studied in the chapter 4 and 5. The chapter 6 introduced the programming method and the function of the program; the hanger tension and structure system transform characteristic of the PingSheng Bridge were introduced in the chapter 7. The research conclusion and prospect were given at last. Main contents are shown as following:(1) Based on presenting the segmental catenary theory for main cable shape-finding and its basic equations, the varieties and features of the solution to cable segmental state equation which is also part of basic equations were studied and the situation when equation has no solution and the problem about iteration convergence route were pointed out.(2) The general thought and process of calculation for main cable shape-finding were given. The nominal stiffness during vertical deformation was put forward as a new concept. The formulae for the alteration stiffness of cable alignment and the nominal stiffness during vertical deformation were deduced. The method and procedure for cable shape-finding and excursion calculation of the saddle under dead loading were defined which used the searching algorithm and the penalty factor. It can converge fast and accurately.(3) Calculation formula for line shape control and cord clip lofting was derived which has great value in project.(4) Calculation method of designed saddle position was established based on new discussion of the definition of theoretical culmination.