The Influence Of Force Frame For Ultimate Bearing Capacity Of Reinforced Concrete Arch Bridge

The reinforced concrete rib arch bridge is most widely used in Southwest China during the 1990s. The force frame is a new structure type and construction method of it. However, there is no much statement about the influence of the force frame on the ultimate bearing capacity of reinforced concrete arch bridge. Therefore, concluding the influence law of the force frame is significant to solve the problems of the concrete rib arch bridge carrying capacity evaluation and guarantee the safety of the construction and using of the bridge.During the surveys, a large number of reinforced concrete rib arch bridge study theories and experimental data are collected. Based on that, the study theories and methods of reinforced concrete arch bridge bearing capacity are introduced in detail. Meanwhile, the finite element analysis is applied to the ultimate carrying capacity evaluation of reinforced concrete rib arch bridge. With the finite element analysis software Midas FEA, a finite element model to study the action effect and resistance effect of the bridge is established. The model is based on the Jialing River Reinforced Concrete Bridge in Zhaohua of Sichuan. The whole damaged process model study of the bearing capacity of reinforced concrete rib arch bridge is performed and the relevant finite element analysis results are extracted. In addition, using the specification and related researches for reference, this thesis takes the quantitative method to analyze the state of carrying capacity of the rib arch bridge, and summarizes the theoretical method about how the force frame influences the ultimate bearing capacity of reinforced concrete arch bridge.The evaluation model of the influence of the force frame on the ultimate bearing capacity of reinforced concrete arch bridge, which is summed up through theoretical analysis, has strong feasibility and applicability. It can be applied to bearing capacity evaluation of the reinforced concrete arch bridge in China.The main conclusion from the analysis results is as follows:①The bearing capacity of reinforced concrete members with force frame is greater than non-reinforced concrete structures. From the theoretical point of view, mainly because under the action of the bending moment, part of the force frame is tensioned eccentrically, and part of the concrete is compressed eccentrically. Therefore, the bearing capacity of reinforced concrete members is greater than the simple sum of the bearing capacity of concrete part and force frame part. In practical calculation, however, it still can be simplified.②The separate consideration of material nonlinearity or geometric nonlinearity is relatively smaller than the latter stress calculating result; but without taking the bond-slip between force frame and concrete into account, and bonding the shared nodes of the two materials will lead to error and cause a larger gap with the actual situation. Therefore, it is necessary to perform the dual non-linear simulation during the calculation of the bearing capacity of the steel reinforced concrete structure, and the bond-slip between the force frame and concrete should be taken into consideration.