Simulation And Local Stress Analysis Of Steel Box Tied Arch Bridge By Incremental Lunching Method

Steel box tied arch bridge is more and more widely used in practical engineering.They combine arch bridges and girder bridges to fully exploit the advantages of the two types of bridges and overcome the mechanical defects of arch bridges and girder bridges.This type of bridge can increase the spanning ability of the arch bridge,meanwhile reduce the bending moment of the beam bridge so as to achieve more excellent use effect.At the same time,Incremental lunching method is mostly applied to prestressed concrete bridges in China and abroad,and there is little research on incremental lunching method of steel structure bridges.Therefore,it is necessary to simulate incremental lunching method with beam and arch composite structures,and detailed analyze the stress of the bridge.This paper uses a certain bridge as an engineering foundation to carry out calculations in incremental lunching method and analyze the key problems in the construction process in detail.This paper firstly introduces the characteristics of the beam-arch composite structure bridge and the principle of incremental lunching method.This paper also summarizes the development history of the incremental lunching method and the current research status.A detailed description of the equipment used in incremental lunching method is narrated.The basic solution process of the finite element method and the modeling method of incremental lunching method are described.This paper describes the general modeling idea of two kinds of incremental lunching method.Secondly,this article introduces the engineering background of the project overview and the steps of incremental lunching method and describes construction contents in the way of graphic composition.Based on the force characteristics of the bridge,the spatial finite element model was established by using the structure finite element software Midas/civil and simulated the incremental lunching method of the bridge.At the same time,stress sensors are laid on the key cross-section of the bridge structure.The sensor can monitor the real bridge incremental lunching process in real time and continuously,and obtain true andreliable measured stress values.By comparing the actual measured value with the calculated value,the results of the simulated calculation are verified and it can be concluded that the simulated calculation result can reasonably and accurately reflect incremental lunching method of the bridge.Finally,according to the force characteristics of the beam-arch composite structural bridge obtained by simulated calculation,the most dangerous working condition and the most dangerous cross section of the bridge structure in the overall pushing construction process are obtained.Under the premise of the most dangerous working conditions,this paper analysis the stress of the bridge structure.This paper mainly analyzes the changes of the top reaction force of the bridge structure and the local stress of the tie beam under the condition that the bridge structure is not synchronized,and the variation rules of the top reaction force of the pier and the local stress of the tie beam are obtained.