Study On Stability Of Single Rib Arch Box Closure Stability Of Long Span Box Arch Bridge

Reinforced concrete box arch bridge is one of the most widely used types of bridges in China.Long-span and extra-large span-supported box-and-frame arch bridges are often constructed using precast arched cable hoisting technology.If the arch box single rib is closed during construction,the stability of the rib is one of the issues that need to be considered.As the span of the arch rib increases,the stability problem after the single rib of the arch box is closed is more prominent.The arrangement of the transverse cable wind rope plays a key role in improving the stability of the arch rib.At present,the corresponding "Specifications" does not have a clear calculation method for the calculation of the stability of the arch ribs of the transverse cable,and there is also a corresponding literature for the stability of the single-ribbed arch with the transverse cable.Research.In view of this problem,on the basis of summarizing and absorbing the research results of predecessors,this paper focuses on the stability problem after the arch ribs are closed.The main contents involve the following aspects:Based on the relevant stability theory and existing research results,combined with the structural behavior characteristics of the long-span box arch rib stability analysis,a numerical simulation model of ANSYS arch rib stability analysis based on finite element principle is established.Based on the actual bridge engineering,the influence of arch rib boundary conditions on the stability of buckling analysis is analyzed.The variation law of buckling stability coefficient of arch ribs with transverse cable and cableless cable is compared.Through a large number of numerical simulation results,the buckling stability coefficient and geometric nonlinear stability coefficient of single rib arch box under transverse cable wind cable are obtained.And consider the stability coefficient of geometry and material double nonlinearity,and compare the difference between each stability coefficient;also discuss the influence of cable tension initial tension,cable horizontal angle,cable longitudinal angle change on arch rib stability.Based on a large number of ANSYS numerical simulation results,the buckling stability and material and geometric double nonlinear stability of different span arch ribs between 100 m and 200 m are analyzed.According to the influence factors of arch rib span,arch axis coefficient,arch rib span ratio and cable tension initial tension,the influence law of arch rib stability is analyzed.Using the principle of mathematical statistics,the regression affects the influence effect equations of each influencing factor,which is convenient for estimating the stability of the arch rib.