Two Different Thrust Structure Arc Bridge Structure Static Performance Comparison

According to the arch rib, tie bar (beam) and the connection bridge pier, arc bridge canbe divided into rigid frame composite arch bridge and department arc bridge two kinds.Composite arch bridge upper structure of the simply supported on the pier, belong to no thruststructure and frame arc bridge, arch, pier consolidation tie bar tensile stiffness, the smaller theincrement of horizontal thrust at arch is mainly composed of bridge pier and arch rib, underconsidering the tie bar deformation after it is the structure of thrust. The solution to the archfoot horizontal thrust is not the same, given the two bridge is widely used in modernizationconstruction in our country, so this two kind of arc bridge related research is very urgent andnecessary.Take Daqian harbor bridge as the engineering background, this paper carried out theabove two different thrust structure of the arc bridge static performance analysis andparameter of the related research work, the main work done is as follows:(1) introduce the thrust composite arch bridge with rigid frame structure characteristicsof arc bridge, the comparative analysis of both stress performance, mechanism and structureof two types of arc bridge arch foot horizontal thrust simplified calculation;(2) instance modeling on these two different thrust structure arc bridge’s staticperformance were analyzed, including the constant load and live load under the action of thestatic performance analysis, given the external frame arc bridge hyperstatic structurecharacteristics, and the frame arc bridge under the loads of additional (mainly includestructure overall difference in temperature and bearing lateral) under the action of the staticbehavior of a detailed theoretical analysis and summary;(3) at the port of money bridge (rigid tie bar arch rigidity) model as an example, thebeam stiffness constant, the beam stiffness ratio of value in the case of other conditionsremain unchanged change from1/10to10/1, a total of11sub model is established. Thenrespectively analysis of the structure internal force under different ratio of beam stiffnesschange, find out the stiffness ratio changes under the changing regularity of the structure.Got the following conclusions:(1) under the action of dead load, rigid frame arc bridge compared with no thrust composite arch bridge, the structure of both state basic similar, all belong to zero thrust archtype system, the former only in numerical value will be reduced, it is by the beam frame arcbridge to reduce the dead weight.(2) under the action of live load, the axial force difference is not big, arch rib bendingmoment difference obvious, mainly displays in: no fulcrum of thrust system of compositearch arch bridge vertical counterforce is slightly bigger frame arc bridge, arch foot nohorizontal force completely, the upper structure on foundation also almost don’t producebending moment; Rigid tie bar arch system produce bending moment and bending momentlarge arch foot, arch rib maximum bending moment is greater than zero thrust system ofcomposite arch arch bridge arch rib biggest bending moment.(3) additional loads without thrust composite arch bridge, the internal force change; Andadditional loads for statically indeterminate frame arc bridge, because of its expansion in thehorizontal direction is restrained, so the cooling system up and pile bending moment causedby lateral structure is larger, even close to the constant bending moment caused by live loadstructure, the analysis needs to be carefully considered.(4) for the arch bridge of the arch thrust composite arch system and beam rigid tie bararch rigidity, undertaking the moment when the beam stiffness value than at about1/2, archrib bending moment is greatly reduced, more suitable for the compression of arch rib collarbeam tension, no mechanical characteristics of thrust composite arch bridge, and when=1/2,collar beam midspan deflection value is relatively reasonable, the overall stiffness is better.