Study On The Ultimate Bearing Capacity And Strengthening Technology Of The Abdomen Arch Ring Of Hollow Arch Bridge

Hollow masonry arch Bridges have a long history and are widely used in China.At present,there are various kinds of diseases in the abdomen arch ring of hollow masonry arch Bridges in service,which lead to many arch Bridges working with diseases.Crack disease has the greatest influence on the bearing capacity of arch bridge.It is instructive to determine the cause of fracture formation for restraining fracture formation and development.There are many reinforcement methods for the cracked web arch ring of hollow arch bridge,but many of them are not ideal.It is of great significance to evaluate the reliability of different reinforcement methods by analyzing the feasibility of various reinforcement measures.In this paper,the ultimate bearing capacity of the web arch ring of different structural systems,the main causes of the cracking of the web arch ring,and the reinforcement effect of different reinforcement methods were studied.The main work content is as follows:1.Based on Abaqus general finite element software,many physical simulation models of the abdomen arch ring of an arch bridge with different types of arch hinges were established to analyze its ultimate bearing capacity.Midas/Civil design finite element software was used to establish the beam element model with different types of arch hinges,and the mechanical behavior of the simulated solid model and the beam element model was compared and analyzed.A simplified method for accurately simulating different arch hinge structures in the calculation model of large complex beam element structure was summarized。2.The model of the hollow arch bridge is established to analyze the boundary displacement characteristics of each abdomen arch ring of the hollow arch bridge with no hinge,single hinge,double hinge and triple hinge.At the same time,the influence of different arch axis shape and different ratio of arch rise to span on the boundary displacement of hollow arch bridge is studied.In this paper,the cracking causes of the abdomen arch ring of the hollow arch bridge are analyzed according to the cracking situation of the arch ring of the hollow arch bridge when different types of loads are applied on the hollow arch bridge.3.The crack generation and distribution characteristics of concrete and brickwork arch rings under load were studied by fine simulation model.Hollow arch bridge is often designed by the end abdomen arch ring arch hinge to reduce excess constraints,reduce the number of statically indeterminate to optimize the force transfer of the structure;However,due to construction conditions or other factors,no arch hinge was established in end abdomen arch ring,resulting in severe cracking of the end abdomen arch ring.It is also a process of the energy release and stress redistribution of the end abdomen arch ring.The ultimate bearing capacity of single-hinged,double-hinged,three-hinged and the structure of hingeless abdomen arch ring with different size cracks in the corresponding position of arch hinge is compared and analyzed.The difference of structural mechanical behavior between hinged and unhinged arch rings after cracking was studied.4.Based on the solid finite element simulation model of Abaqus,the post-reinforcement feasibility study was carried out for the reinforcement of hollow arch bridge with the reinforcement method of enlarged section of the arch ring and the reinforcement method of pasted steel plate.According to the conclusion of the study,neither the reinforcement method of increasing section nor the reinforcement method of pasted steel plate can restrain the occurrence of new cracks.Finally,according to the research results of the analysis on the ultimate bearing capacity of hingeless,single-hinged,double-hinged and three-hinged abdominal arch ring as well as the characteristics of the generation and development of cracks,this paper analyzes the treatment method of pre-cracked abdominal arch by cutting joints.According to the analysis results,it is found that cutting the arch ring can effectively inhibit the development of cracks.