Study On Mechanical Performance Of Main Arch Of Concrete Arch Bridge With Cable-hoisting Method

The section of the concrete arch consists of precast arch ribs and cast-in-place longitudinal joint concrete and roof concrete,the essence of the concrete arch ring section is a combined section with different stress distribution;after concrete arch ribs are closed,the longitudinal joint and roof concrete were poured in turn,and the arch ring section is finally formed.At present,the strength and bearing capacity of main arch of concrete arch bridge adopted cable hoisting construction method were calculated by“Code for the Design of Highway Bridges and Culverts” or the “Code for the Design of Reinforced Bars and Prestressed Concrete Bridges and Culverts”,the influence of stress history on the mechanical behavior and bearing capacity of the structure in the combined section of the arch were not taken into account;So far,few the oretical studies have been done on the checking method of the bearing capacity of the arch ring based on the stress history of concrete box arch bridge in construction.This paper takes the Haima Bridge which has a main span of 180 m as the engineering background,and by using the finite element software MIDAS/Civil to establish a combined section of arch ring to consider the construction process of each component.Comparative analys is of internal forces and stresses between bare arch and bridge completion stage,and,the differences between construction by stages and construction in one stage,are carried on.Meanwhile,the influence of concrete shrinkage and creep on stress redistribution of arch section in phased construction has been analyzed.Due to the large stress in the rib section and the less stress in the longitude joints and the roof,when the section of the arch was damaged by the ultimate bearing capacity,it must begin with the component with the highest stress.Thus,based on the “Code for the Design of Highway Bridges and Culverts”,Section reduction method has been proposed,which is an improving checking method for the ultimate bearing capacity of the current combined section,and the history of stress influence is taken into account.Further more,to analyze the influence of construction processe and completion state on dynamic characteristics and stability of structure by using MIDAS/Civil.The results of structural dynamic characteristics and stability of the bare arch state and the bridge state will be compared,and the influence of dynamic characteristics and stability of the arch on the bare arch and the bridge state will be discussed.