Research On The Construction Monitoring And Seismic Response Of CFST Tied-Arch Bridges

Through the present situation analysis of concrete filled steel tubular(CFST)tied-arch bridges,the key role of construction monitoring playing in bridge construction has been realized.The seismic analysis of bridges also has great theoretical and practical guiding significance for structural safety.In this paper,taking a CFST tied-arch bridge as an example,the research on it was carried out from two aspects: construction monitoring and seismic response.The main contents of this paper are described as follows:(1)By consulting abundant documents in home and abroad,the characteristics of CFST tied-arch bridges development were reviewed.The different classification of CFST tied-arch bridges were summarized in detail,and the current research status of construction monitoring and bridge seismic were introduced.(2)The content,objective,and scheme of the real-time monitoring of the CFST tied-arch bridges in each construction stage were systematically summarized.The theory,advantages and disadvantages of three seismic analysis methods were introduced in detail.(3)Through monitoring the construction process of this CFST tied-arch bridge,The results indicate that the theoretical values and measured values of the five sections of the main girder are consistent with the trend of the operating conditions.The main beam monitoring section was subjected to compressive stress,and the maximum compressive stress was not exceeding the stipulated limit.The main beam and arch rib are safe in the construction process.The measured values meet the engineering precision requirement.(4)By modal analysis,It was found that the CFST tied-arch bridge does not resonate with the bridge,and the basic mode of vibration is the lateral inclination of the arch.This CFST tied-arch bridge has no separation between the beam and the arch in the low-order mode,which is the effect of the lifting rod to effectively connect the arch rib and the girder.(5)The movement trend of CFST tied-arch bridge under transverse,longitudinal and vertical earthquake wave are respectively coupling vibration of the arch rib in transversal and vertical directions,moving sideways in transverse direction,and vertical motion.The peak axial force of arch rib is maximum in transverse seismic wave E1 and E2 under the action of earthquake response;and the peak bending moment is maximum in longitudinal direction.The peak shear force and bending moment of abutment in longitudinal seismic wave E1 and transverse seismic wave E2 under the action of earthquake response is maximum.