Comarative Study On Strengthening Method Of Simply Supported Beam Bridge Based On Crack Diseases

Most of the active support bridges in China were built and put into use from the early 1960 s to the late 1980 s.From the preliminary theoretical design to the on-site construction technology and the overall supervision system of the project,the aging of the bridges completed during this period was accelerated.After several decades of operation,the bridge has encountered many serious problems,such as horizontal and vertical longitudinal cracks in the deck,partial damage to the abutment edge settlement,serious collapse of the cone slope at the edge of the bridge,and serious vehicle jumping at the bridgehead.The parts basically covered all the components of the bridge structure,which seriously affected the normal operation of the traffic and had a large potential danger.Due to the vigorous development of the transportation industry and the ever-increasing huge traffic volume,the phenomenon of overloading of actual vehicles has become more and more significant,and the bridge site is in a pathological state due to active man-made or external environment and other factors.Therefore,taking measures to strengthen the diseased small and medium-sized bridges and extending the normal service life is the main method to ensure the smooth and smooth traffic flow and reduce the project cost.Relevant practice shows that the damage and disease of any concrete member will generally appear in the concrete structure.The distribution of cracks is the main criterion for reflecting the concrete structure disease.Therefore,the diagnosis and analysis of the research on the damage of concrete structures should be carried out on the aspects of structural crack assessment,testing and regional analysis.The causes of cracks in steel-concrete structures are varied and many factors interact with each other,but each crack is produced by one or more factors.Based on the analysis of the basic diseases of steel-concrete girder bridges,three common reinforced concrete structures were obtained by calculating the three methods for conventional reinforcement of simple-supported girder bridges,and considering the requirements of construction technology and economic investment.The advantages of the reinforcement method and the usability of the actual situation,combined with the use of finite element software to evaluate the effect of reinforced concrete after reinforcement.The basic principle and calculation method of the existing reinforcement method are mainly introduced.The reinforcement effect of the reinforcement beam bridge by two conventional methods,such as anchor plate and carbon fiber,is studied.The positive section limits of the simply supported T-beam bridge are analyzed.Factors such as flexural capacity,maximum deflection,transverse stiffness,overall plastic load carrying capacity,and distribution of cracks.It is found that the anchor plate reinforcement method can significantly improve the ultimate bending capacity of the reinforced concrete simply supported T-beam bridge,the in-depth development of the constrained crack and the overall increase of the structural stiffness;the carbon fiber method and the bonded steel plate method can effectively improve The plastic deformation ability of the component is convenient for practical engineering applications.