Research On Tie Bar Replacement Construction Technology Of The 3^rd Fujiang Bridge

Since the 1990 s,China usually regards tied arch bridge as the preferred bridge type for 100-500 m span.This kind of bridge has many advantages,such as beautiful appearance,strong spanning ability,good site adaptability and good econommic,so it has been fully developed and span records are constantly being refreshed.Due to the influence of three factors,there are many defects in this type of bridge,especially the problem of durability and replacement of tie bar.The first is that the level of traditional craftsmanship is limited the construction technology,followed by the lack of sufficient understanding in this bridge type,and finally,insufficient management and maintenance.On the basis of relevant data and summarizes the development of tied arch bridges,especially the method of reinforcement of tie bar.Finally,based on the reinforcement of the 3rd Fujiang Bridge,systematic research on tie-bar replacement construction technology of the bridge.(1)Introduces the general situation of the 3rd Fujiang Bridge,as well as three tiebar replacement solutions proposed in the early stage of bridge reinforcement.Based on the relevant research,summarize the advantages and disadvantages of each program and the feasibility of construction.Finally,analyze the construction difficulty of the selected scheme(2)Around the implementation of tie-bar replacement,analyse the construction process,construction technology and quality assurance measures.Mainly includes the temporary support construction of the side span,mass concrete construction,tie bar removal and installation,tensioning of tie bar,ascent of the approach bridge and steel stringer installation.(3)In order to achieve the construction control objective,calculate the control threshold for tie bar tension and analysis the operation requirements for tie bar tension.The sensitivity of bridge structure is analyzed by numerical simulation and defined the key monitoring sites of the bridge.Introduce the monitoring arrangement during actual construction and analyze the effect of construction controlAfter the completion of the reinforcement of the 3rd Fujiang Bridge,the bridge has been restored to its ideal state.Practice has proved that this tie-bar replacement program is technically feasible,which has good economic and good practical promotion value,can be used for other similar tie bar arch bridge replacement.