Study On The Geometric Nolinearity And Construction Control Of Long Span Cabel-stayed Bridge

Comparied with suspension bridge, Cable-stayed bridge are characterized with the high structrual stiffness, self-anchored system for axial loads, and simple application of cantilever construction method. It is more advantageous in wind-resistant stability, ecnomic effect, and especially adaptability for severe geological conditions. For all this strongpoints, cable-stayed bridge becomes the main choice of long span bridge. At present, there is no successful ready-to-wear experience for the cable-stayed bridge which the main span exceeds 1000 meters. With the increase of span, also the use of hige strength materials, the stiffness of cable-stayed birdge rapidly descends, which could lead to some new mechanic problems effecting the performance. When the span is very large, some factors what are not important in routine span become dominant, and nonlinearity is the one of these factors. Furthermore, due to the highly coupling character between the design and construction, the study on the construction method and construction control is focused by cable-stayed bridge researchers.Focusing on the superlong span cable-stayed bridges such as Su-Tong Bridge, this dissertation deeply discussed the nolinearity and construction control of superlong span cable-stayed bridges by finite element analysis, and especially the geometry control method is comprehensively studied, and the results are applied at the construction control of Sutong bridge. Based the geometry control method, the construction techniques are rationally and ecnomicly chosen, the consturcition progress and procedures are rationally ordered, and the construction is efficiently monitored, which aimed to sutisfy the requirements such as cable force, profile, height of girders. The main content is at below:(a) Study of the theory on nonlinear analysis and construction control of cable-stayed bridge are comprehensively reviewed, and the next work on the nonlinerity and construction control is presented.(b) The construction control system and methodology of cable-stayed bridge is introduced. Some The task, the content, the principal, the method, and the factors effecting the control is expatiated. And the simulation of the construction process is discussed. (c) The theory of nolinearity at cable-stayed bridge is introduced, the geometric nolinearity and material nolinearity are summarized, the finite element solution and its computer implementation of geometric and material nolinearity is debated.(d) The nonlinear finite element analysis is done, and the construction process is simulated. The nonlinear analysis results are compared with the linear ones to study the nonlinear effect. Furthmore, the parameters impacting on the nonlinearity are analyzed, and the structural characteristics during the construction process are evaluated.(e) Based on the nonlinear analysis, the geometry control method and the control precision is studied. The basic geometric control ideology is introduced, and the parametric study is done to investigate the control principles and precision requirements.(f) It indicates basic principles of geometry control, confirms its procedure. Applying the deterministic method, it does sensitivity analysis to primary parameters in construction control of Sutong Bridge.(g) The conclusions and prospects are summarized at the end.