Test Study On Mechanical State Of Space Joint With Nine Members For A New Type Railway Steel Truss Arch Bridge

The DPSD Bridge is a long span and new type railway steel truss arch bridge with double arch ribs. The span arrangement is (85.75+286+85.75) m. The G11joint is a key joint of bearing load for the whole bridge, which is located in the boundary between bottom arch rib and bottom chord bar of the DPSD Bridge and there exist nine members of spatial connection. The structure construction of the G11joint is very complicate. Mechanical behavior of the G11joint was studied in this thesis by means of FEM analysis and model test. The major work is summarized and achievement is obtained as follows:1. Based on the results of the space finite element analysis of the whole bridge, selected the G11joint and established the local refined finite element model. Determined unfavourable load combination and related boundary conditions, the Mechanical behavior of the G11joint was analyzed.2. Determined the scale ratio of1:4for the G11joint test model, considering comprehensive various factors, such as the test equipment the supply of market material、the test field and so on. Based on similar-ratio principle, designed and produced an experiment model of the G11joint.3. The testing scheme was determined and the space finite element analysis of the G11joint test model under various load conditions was completed. Compared the finite element analysis results of the actual G11joint local model with the test model, so that ensure that the model test can faithfully simulate the mechanical state of the actual G11joint.4. Two kinds of unfavourable load conditions and one kind of overloading test were achieved. The experimental results were agreeable to the theoretical analysis results, and the stress level of each member was less than designed value. The test model of G11joint was in linear elasticity under the overloading conditions, this shows that G11joint has sufficient carrying capacity, and there is a large surplus left.Currently, there is not that kind of complicated space joint test study similar to the G11joint at home and abroad. Therefore, the research results and the test study method of this thesis not only provide the basis for design of the DPSD Bridge, but also can provide references for study and design of other similar joints. This paper has83graphs,25tables and52references...