Research On Constraction Control Of Concrete Filled Steel Tube Arch Bridge

The main aims of construction controlling of long-span CFST arch bridge are to make the line shape and the internal force of the ribs achieve the requirement of the design and the standard codes at the extremely extend as well as to ensure the security during the construction. Based on the Qiandaohu Bridge, this paper has a research on the methods of searching for the forces of the stay cables, the controlling methods of the ribs shape, and the optimization methods of the concrete filled sequence. The main contents of this paper are summarized as follow:1,Taken the safety factor as the objective function during the ribs hoisting construction, the optimization method of cables pulling is given. Firstly, we identified the difference between the various methods of cables pulling, and then noticed the principle that the restraining of the displacement determined the cables forces needed during the ribs hoisting. Among all of the possible methods of cables pulling, there must be a most optimization method that could assure the cables forced achieve its lowest limit so that the security of the structure achieves its highest limit.2,The four control shape of the ribs are compared with each other in different construction condition. The relationship between the displacements during the construction and the pre-elevations during the hoisting is illuminated in the chapter three. Two different control methods are given in this chapter too. Finally, the Qiandaohu Bridge is taken as an example to show the different requirements of the pre-elevation for different methods of cables pulling.3,Because the filling of concrete into the steel tube is the key process in the construction, so it is necessary to design a reasonable order to achieve the efforts that the safety factor of the structure stability reaches its most up level and the internal forces reach the lowest level. In the chapter four, we take the safety factor of the stability during the concrete filling process as the objective function, and optimize the concrete filling orders by the exhaust algorithm method. We could design the concrete filling sequence by elastic stability analysis method and test the result by the plastic stability analysis method.