Structural Behavior And Dynamic Characteristics Analysis Of U-shaped Aqueduct With Multi-factor Influence

Aaqueduct is a space thin-walled Water Conveyance Structure that spans the valley,depression,road and so on,which is widely used in agricultural irrigation engineering and other large-scale water conservancy projects and plays an important role in alleviating the uneven distribution of water resources in China.During the actual operation,aqueduct structure is often affected by factors such as the coupling effect between water body and aqueduct body,the ambient temperature,the wind load and the concrete deterioration.Coupled with the early construction of part of the aqueduct structure has been unable to meet the requirements of the existing design standards or needed to strengthen,repair.Therefore,it is far-reaching to analyze the structural behavior and dynamic response of the aqueduct structure with multi-factor influences.Combining with the geographical characteristics and operation of Jingdian project,the numerical simulation method is used to study the structural behavior and dynamic characteristics variation law of aqueduct structure with multi-factor influences.Base on the engineering design data,the 3-D finite element model of aqueduct structure was established,and the structural behavior of aqueduct structure under water load,wind load,temperature load and concrete deterioration was analyzed to explore the sensitivity of the different factors on the structural behavior of the aqueduct structure,which provides a theoretical reference for similar engineering design calculations.According to the principle of additional mass method and fluid-solid interaction method,the three-dimensional finite element dynamic model of aqueduct structure with different coupling forms are built,and the modal calculation need to be calculated and analyzed under different water levels by using different modal extraction methods.Then,the modal frequency among added mass model,FSI model and HHT method under normal water level condition were compared to select the high-precision model for the analysis of dynamic characteristics of aqueduct structure.Finally,combined with the environmental characteristics and the material parameters after the deterioration of the concrete to study the influence of the vibration characteristics of the aqueduct structure under the temperature load,wind load and concrete deterioration.Taking the limited ground domain as the research object,the viscoelastic artificial boundary verification model was built,and the seismic response of the ground wave is analyzed by the ground motion input method with equivalent load.Then,the simulation results are compared with the analytical results to verify the correctness of the method.Based on the above research results,the seismic response analysis of aqueduct structure is studied under water load,wind load,temperature load and concrete deterioration.The distribution of dynamic displacement and dynamic stress of aqueduct under different factors is studied,which can provide theoretical basis for the subsequent reinforcement,transformation of the project.Meanwhile,it can also provide design reference for similar projects.