Static And Dynamic Analyses And Optimization Of Suspended Monorail Continuous Beam Bridge With Portal Piers

With the development of urbanization in China and as a new type of rail transit in line with the concept of urban green development,suspended monorail system has been widely concerned by many medium-sized urban planning builders with many advantages such as small space use,strong adaptability and high reuse rate.However,the relevant technologies in China are not mature enough and the research results are insufficient.Besides,there is no unified standard.Based on a test line project,the static and dynamic performances of this type of rail beam are studied theoretically and calculated.Parameters of the beam section are optimized and studied,and the optimization scheme is proposed,which provides theoretical basis and reference for the realization of the localization of suspension monorail transportation technology and the formulation of relevant track beam specifications in China in the future.Firstly,research background of suspended monorail system rail beam bridge is introduced and design characteristics of suspended monorail system rail beam is summarized.Then the development history of suspended monorail transportation is expounded.The design scheme and structural form of a 40+60+40m monorail continuous steel track girder bridge with portal pier suspended system is introduced and the spatial finite element model based on beam element is established by using MIDAS/CIVIL software.The stresses and deformations of the structure under constant load,train live load,transverse load,wind load and temperature load and their combinations are analyzed and calculated according to the relevant specifications.And the natural vibration characteristics of the structure are calculated and analyzed by using the whole bridge model with and without considering the pile-soil action,and the influence of pile-soil action on the dynamic characteristics of the structure is compared.The response-spectrum method and time-history analysis method are used to calculate the seismic response of the structure.Using the large general finite element software ABAQUS,the detailed finite element model of the whole bridge based on solid element and plate and shell element is established,and the stresses and deformations of the structure under the joint action of the train load under the constant load and the three most unfavorable loading positions are analyzed,and the corresponding check calculation is carried out.Finally,according to the characteristics of the section of the bridge,the influence of each section parameter on the deformation,stress and steel consumption of the rail beam is analyzed,and the section is optimized.Finally,the steel consumption of the optimized rail beam is reduced by 16.4%.