Research On The Replacement Technology Of The Suspension Rod Of The Reinforced Concrete Tied Arch Bridge Without Support

The tie-rod arch bridge connects the tie rod(beam)and the arch rib as a whole through the hanger rod,and the hanger rod transmits the constant live load of the bridge deck to the arch rib,and then to the arch foot.The hanger is the key component of the whole bridge,and it is also the weakest component of the tied arch bridge.Due to the special service environment of the boom,the design service life of the boom is far less than the design life of the whole bridge,and the replacement process of the boom is essential.At present,the boom replacement technology with support is commonly used for boom replacement,but this technology is difficult to construct,has a long construction period and high cost,and interferes with the traffic on the bridge deck,which is not suitable for the requirements of rapid traffic development.The unsupported replacement boom technology relies on the structure’s own bearing capacity to complete the optimal distribution of cable force,and the construction is simple and easy to operate,does not hinder the normal passage of the road,and is time-consuming and low-cost.However,the current research on unsupported boom replacement technology is still shallow,and the complete set of replacement technologies and solutions are not yet mature in practical applications.The replacement of a single boom without support has certain safety hazards.Therefore,it is of great practical significance to study the unsupported replacement boom technology of reinforced concrete tied arch bridges.In this paper,based on the current research on the replacement technology of supported and unsupported booms at home and abroad,combined with supporting projects,in order to realize the boom replacement technology without support and form a realistic and feasible implementation plan,the finite element numerical analysis method and Field tests were co MPared and combined methods,and the following research contents were carried out:1.Analysis and research on the stress condition of the main load-bearing members of the tied arch bridge under the condition of replacing a single suspenderThe finite element analysis method is adopted,and the finite element model is established by Midas Civil software to simulate the stress conditions of arch ribs,tie beams,and remaining booms during the removal and replacement of a single boom without support,and the safety of the stress conditions is carried out.Analyze and find out the law of stress conditions.2.Research on the replacement scheme of multiple boom combinationsAccording to the theoretical calculation results of the unsupported replacement of a single boom and the law of force conditions,the stress conditions and laws of simultaneous removal and replacement of multiple booms are studied,and a feasible technical optimization scheme for the combined replacement of multiple booms is formed.3.Research on the force safety of key parts of tied arch bridge during boom replacement processUnder the premise of forming a feasible boom replacement scheme,the stress safety of some key parts during the boom replacement process is studied to ensure that the multi boom replacement process does not damage the bridge durability.4.On-site implementation plan optimization for boom replacementOn the premise of theoretical analysis,a feasible on-site implementation plan is formulated and implemented,the force and deformation data of key parts during the implementation process are collected,and co MPared with the theoretical data,the implementation plan for boom replacement is further optimized.Combining the supporting projects,this paper analyzes the stress condition of the removal and replacement of a single suspender of a reinforced concrete tied arch bridge through theoretical analysis and on-site implementation process,and innovatively proposes a technical scheme for the combined replacement of multiple suspenders.Its feasibility and safety were studied,and a feasible implementation plan for the suspension rod of the whole bridge was formulated.The research results of this paper put forward a new feasible scheme for the replacement of suspension rods of similar tied arch bridges,with broad application prospects and long-term engineering significance.