Research On Mechanical Behavior Of Large Span Pipeline Suspension Bridge

In recent years, long pipeline suspension bridges have been built in the construction of various oil and gas pipelines in China. The cable system of the pipeline suspension bridge is more complex, wide span ratio is relatively small, the lateral stiffness is insufficient, and the structure is easy to produce large deformation under the action of wind load and earthquake, which leads to the structural damage. By means of the finite element software, the paper realizes the iterative form finding of the large suspension bridge. On the basis of this, the related research is carried out on the static, tower bottom restraint condition, dynamic characteristic, pipeline cleaning load and the seismic performance of the structure. The main work is as follows:(1) On the basis of summarizing the iterative method of form-finding of the suspension bridge, the structure of the pipeline suspension bridge is formed with the finite element software;(2) The static load stress characteristics of the pipeline suspension bridge is studied in the typical load conditions. The results show that the operation and maintenance condition is the control condition;(3) The stress behavior of the structure effected by different types of tower bottom constraint is studied based on the typical load condition and different span ratios of structure,Results show that comparing hinge structure with consolidation at the bottom of the tower setups, structure static calculation results are slightly different, The hinge structure arranged at the bottom of the tower mainly benefits the tower construction and the bottom of the tower without bearing bending moment in order to save the dosage of tower materials;(4) The influence of the structure of the wind and the arrangement of the main cable on the calculation and analysis of the natural vibration characteristics of the structure are studied, the results show that the wind cable system and the main cable arrangement has a great influence on the structural stiffness, and reasonable design of wind cable is helpful to improve the structural stiffness; Main cable card that can increase structural transverse stiffness and torsional stiffness, one main cable structure of transverse bending, vertical bending stiffness has little effect, but the structure of the torsional stiffness decreases for larger;(5) For cleaning piping loads the special working condition, the moving load on the structure of pipe cleaning. The results show that the cleaning pipe load speed on structure forced vibration impact larger, with cleaning up the increase of pipe load speed, The forced vibration of the structure is gradually increased;(6) Through the research on the seismic behavior of the pipeline suspension bridge, the results show that the seismic performance of the structure is good, Deck Truss is weak; The damping ratio has great influence on seismic response of structures, and the larger the damping ratio is, the smaller the structure response is. The seismic force analysis of different main cable arrangement type is carried out. The results show that the external tension of the main cable is beneficial to the seismic resistance of the structure.