Ultimate Loading Capacity Research On Combination Arch Bridge With Steel Web Members-Steel Reinforced Concrete

The combination arch bridge with steel web members-steel reinforced concrete is formed by steel reinforced concrete-steel reinforced concrete which is poured in the top-and-bottom concrete as the part of the arch structure when the arch is constructing. This kind of bridge retains the advantages of the method of steel reinforced concrete construction, making the best of the function of concrete-steel composite structure, and reduces the structure weight, improving the mechanical performance of concrete arch greatly, which has a wide application. The research of a 420 meters combination arch bridge with steel web members-steel reinforced concrete has carried out, with the trial design, steel reinforced concrete short column experiment and calculation theory research. Based on the 420 meters combination arch bridge with steel web members-steel reinforced concrete, the research carries out the model test and makes the finite element analysis of its ultimate bearing capacity. This research gets the results of the entirety forced performance, failure mode and simplified calculation of ultimate bearing capacity. The main task and main conclusions are as follows:(1) With the trial design of 420 meters combination arch bridge with steel web members-steel reinforced concrete as the prototype, Designing and making and 12 meters span arch model, and loading testing for the asymmetric load at two different points. The experiment results show that the failure model of this type combination arch is close to second-class stability, and crack along the arch axis direction goes faster than that along the section height direction developments. The whole loading process can be divided into three stages:elastic stage, elastic-plastic stage and plastic stage. The model finally loses its bearing capacity due to the excessive plastic area.(2) Compared finite element model that adopts general finite element software ANSYS to build a of steel web members-steel reinforced concrete composite arch with experiment results, to verify the correctness of the finite element model. The results show that the finite element model results are in identical with the experiment results. And the established finite element model can well simulate the force performance and ultimate bearing capacity of steel web members-steel reinforced concrete composite arch.(3) Through the parameter analysis of the proved finite element model which is adopted in proceeding to the ultimate bearing capacity. The results show that the main effect factors of ultimate bearing capacity of composite arch are the web members, diameter-thick ratio and pipe diameter ratio between branch pipe and main pipe and so on.(4) Based on the experimental and finite element analysis, referring to relevant specification and research about equivalent beam-column method, establishing the computing method of ultimate bearing capacity of steel web members-steel reinforced concrete composite arch. The computing method is used to calculate the ultimate bearing capacity of the composite arch model, which is proved to have high precision and is partial to safety through the comparative analysis with the experimental and finite element results.