Research On Weak Parts Recognition Theory And Reinforcement Technology Of The Rigid Frame Arch Bridge

Rigid frame arch has many advantages such as fewer components, material saving, convenient construction and low cost, so it’s widely built in our country in the eighties of last century. However, with the development of social economy, load level and traffic are increasing exponentially in recent years, rigid frame arch bridge has been unable to meet the existing requirements and got disease. Therefore, it’s urgently to recognize the weak parts and to do research on the ultimate bearing capacity and reinforcement of the bridge.Taking a rigid frame arch bridge in Beijing Huairou City as an example,First, the paper researched the first stability buckling eigenvalue and the corresponding buckling mode on beam element and elastic model of the bridge, forecast the failure mode of the bridge structure may occur. Which indicates that due to its poor integrity, low lateral stiffness, lateral load transfer unequal and other structure characteristics,bridge will appear more easily instability in-plane for its capacity is not enough under partial load.Secondly, based on the above study, the paper summarized the recognition the weak parts of bridge structure theory, and complete the identification weak parts of arch rib. Structural unit importance coefficient distribution calculated by abaqus finite element software according to the arch ribs in-plane instability. Model experimental verification was carried out to verify that theory. Research results show that the local highest point on the structure importance coefficient curve structural means the weak parts of structure, the significant degree of weak part is directly related to the peak size.Third, further research on calculation method of ultimate bearing capacity of the rigid frame arch bridge under the joint action of the geometric nonlinear, material nonlinear, different load conditions and other factors by Abaqus finite element analysis software through crushing theory and three-dimensional simulation model. The results are validated with each other between finite element model and beam element model at the same time.Finally, according to the actual characteristics of rigid frame arch bridge and weak part recognized above, reinforcement technology is studied and the method of anchor bonded with plate is adopted to improve the bearing capacity. The effect of the reinforcement is verified with the comparison of before and after the reinforcement of rigid frame arch bridge in bearing capacity, unit importance coefficient distribution and cloud image.