The Research On Structure Behavior Of Long Span X-type CFST Arch Bridge During Construction Process

Afer Wangcang East-river bridge was built in 1990 in Sichuan Province, the applications of concrete-filled steel tubular (CFST) arch birdge have been made more and more in recent years. As self-erection structrue, the accurate analysis on the constuction of CFST arch bridge is the decisive factor for realizing the designed goal. Based on Huangshan Taiping Lake Bridge in Anhui province, this paper has done some research on some key problems in constuction.First, the simulation method of construction is studied. "Integer forward analysis, Step backward analysis" simulation method is derived in support of the "element birth and death" function in FEM programs. In this way, we can make emulation of construction sequencing and easy. Comparing with conventional method, we can get more accurate stayed-buckle cable force by optimizing thoery. Do meticulous study on the process of pumping liquid concrete in the steel tube to find the tendency of the stress, deformation and stability of the stuctrue. Analyze the goemetric nonlinear influence during the erection of the arch, not only in ideal situation, but also in the situation of constuction error. Finally, do some research on the shrinkage and creep of the concrete in the steel tube. Based on proper assumptions, deduce the equivalent elastic ratio of the concrete in the steel tube at the influence of creep, by using the constitutive relation from "method of age-adjust equivalent elastic ratio".