Simulation Analysis Of Concretepumping Process Of Concrete Filled Steeltube Arch Bridge

With the rapid development of China ’s economy and science and technology,concrete filled steel tube arch bridge has been widely used in China,and its span is also constantly breaking the world record.China has been in a leading position in the field of concrete filled steel tube arch bridge,but it still faces many huge challenges and difficulties in the construction of concrete filled steel tube arch bridge.In the whole process of arch bridge construction,the concrete pumping process in the concrete-filled steel tube arch bridge is a crucial link in the construction technology of the bridge.It is the key process of the stress transformation of the arch bridge structure.At the same time,it is also the key technology to ensure that the arch rib steel tube and the core concrete are combined with each other and work together.Therefore,the research on the pumping concrete construction technology of concrete-filled steel tube arch bridge is not only the demand of the development of concrete-filled steel tube arch bridge,but also the key to ensure the construction safety of the bridge and the realization of the design goal.Taking Mugao Jinsha River Bridge as the actual engineering background,this paper analyzes and studies the concrete pumping construction process of dumbbell-shaped cross-section concrete-filled steel tube arch bridge from three aspects: pressure change in pumping pipeline,simulation analysis of concrete pumping construction in pipeline and sequence analysis of concrete pumping in pipeline.The main research contents and conclusions of this paper are as follows:(1)Through the analysis of the combined rheological model,the Bingham viscoplastic model is selected to simulate the core concrete,and the combined rheological model is applied to the concrete in the pumping pipe.When pumping concrete,only the pumping pressure is needed to make the shear yield stress of the core concrete near the inner wall of the arch rib steel pipe greater than the shear yield stress of the lubricating layer,and the concrete in the pipe will flow forward in the steel pipe.(2)The EDEM discrete software is used to analyze the pressure loss model of the core concrete in the vertical bending pipe.The pressure loss calculation formula of the actual project is summarized through the model calculation value,and the discrete model can be used in the actual project through the comparative analysis of the model simulation value and the formula calculation value.(3)In the simulation of the concrete pumping construction process and the analysis of the pumping sequence of the Jinsha River Bridge of Mugao Bridge,the theoretical calculation value of the finite element model is compared with the measured value of the project.It can be concluded that it is feasible to use the two arch rib simulation methods of the double element method and the combined section method to simulate the pumping concrete construction process of the dumbbell concrete filled steel tube arch bridge.(4)The relationship between the internal pressure of the arch rib and the stress of the inner wall of the steel tube is studied and analyzed by ANSYS.According to the analysis of the relationship between the internal pressure of the arch rib and the stress of the inner wall of the arch rib steel tube based on the two-dimensional plane model,it can be concluded that the stress at the junction of the steel tube and the batten plate is the largest when the concrete is poured into the arch rib and the inner cavity of the arch rib batten plate,which should be paid more attention in the design and construction.Finally,the linear relationship between the internal pressure of the arch rib and the stress of the inner wall of the arch rib steel tube under different working conditions in the construction process of pumping concrete is summarized,which provides a reference for the conversion between the internal pressure of the bridge and the stress of the inner wall of the steel tube.