Study On Dynamic Characteristics And Damage Cracking Of Aqueduct Under Multiphase Coupling

Aqueducts,as a kind of spatial thin-walled water conveyance building,are widely used in agricultural irrigation projects and other large-scale water conservancy projects,and play an irreplaceable role in achieving optimal allocation of water resources.Aqueducts generally serve as both open channels and bridges.The complexity of their structures and the impact of extreme environments often put them in abnormal operating conditions.In actual engineering,the aqueduct is often located in areas with high winds and earthquakes.During the operation,due to the coupling between the structure and the water body,wind loads and earthquake loads,the structure may suffer local damage,affecting the normal operation of the aqueduct,and even As a result of the overall structural failure,it is of great significance to analyze the dynamic characteristics of aqueducts with multi-phase coupling and to study damage and cracking.In this paper,the Changgangpo aqueduct in Luoding,Guangdong Province is taken as the research object.Based on the local area characteristics and structural operation conditions,based on finite element simulation,vibration detection extraction,modal identification and numerical simulation techniques are used to multi-phase coupling.Analysis of the aqueduct's dynamic characteristics and damage cracking research,the main research contents are as follows:(1)Based on the engineering design data and the measured parameters during the operation period,consider the coupling effect between the water body and the tank body,and establish a three-dimensional finite element model of the aqueduct based on the elastic wave theory.The DASP vibration measurement signal acquisition system was used to collect dynamic measurement data during the operation of the aqueduct,and the characteristic frequency of the structure was extracted through CEEMDAN-SVD noise reduction and the variance contribution rate.Compared with the modal results of the fluid-solid coupling model,the simulation model was verified.Reasonability and accuracy.(2)In MATLAB software,the Davenport spectrum is used as the target response spectrum.The autoregressive model is used to simulate the pulsating wind field.The pulsating wind load is applied to the fluid-solid coupling model of the aqueduct,and the response law of large aqueduct systems under pulsating wind pressure is explored.Structural optimization design provides a theoretical basis.(3)Establish a Housner spring mass model of the aqueduct structure with reference to the "NB35047-2015 Code for Seismic Design of Hydraulic Structures of Hydroelectric Projects",and compare it with the fluid-solid coupling model.Select El-Centro waves as input seismic waves,respectively,for the massless foundation and Two models of viscoelastic boundary are used for seismic acceleration input,and the seismic response law of water-structure-foundation coupling system is explored.At the same time,it is concluded that the fluid-solid coupling effect and viscoelastic boundary can better reflect the reality in scientific research theory.(4)In order to better solve the non-linear problem,we chose to use ABAQUS software,using the plastic damage constitutive of concrete,to calculate the seismic response of the aqueduct structure under different earthquake peak accelerations,and explore the damage cracking law of the aqueduct.