Seismic Response Analysis Of Urban Buried Drainage Pipeline

With the development of social economy,the scale of municipal pipe network has been continuously expanded,and it has gradually become an important part of urban infrastructure construction.As an important part of municipal pipe network system,the drainage pipeline must not only ensure the normal discharge of daily life and industrial wastewater,but also has the important mission of urban flood prevention and drainage and sewage prevention.The pipeline is subject to physical,chemical and biological erosion of wastewater in the pipeline for a long time,which is easy to produce damage to varying degrees.Although the damaged pipeline can meet the basic drainage requirements under normal conditions,it is easy to rupture and leak under the action earthquakes,causing serious consequences.In addition,China has widespread fault zones,frequent seismic activities and severe earthquake disasters.Therefore,it is of great significance to study the seismic response characteristics of the damaged drainage pipeline to mitigate earthquake disasters for the safe and orderly operation of the cities.In this paper,by analyzing the current status of domestic and foreign research on drainage pipeline corrosion and seismic resistance of pipeline,summarizing basic theories such as drainage pipeline corrosion mechanisms and material constitutive models,combining the corrosion mechanism of concrete drainage pipeline with pipeline seismic resistance,the finite element software ABAQUS is used to analyze the seismic dynamic response characteristics of drainage pipeline.On the premise of considering geostatic stress and the interaction between pipeline and soil,the viscous-spring boundary is used to simulate the seismic dynamic response of the urban buried drainage pipeline.The seismic dynamic response characteristics of buried drainage pipeline and the effects of water level,surrounding soil,corrosion defects and other factors on the seismic dynamic response characteristics of the pipeline are studied.Through the analysis,the following main conclusions are drawn:(1)The stress of the pipeline generally shows the distribution characteristics of small upper part and large lower part,and the maximum stress generally occurs near the pin.At the same time,the vicinity of the pin is also the earliest and most serious area of damage and cracking.The stress and damage degree of the pipeline increase with the rise of the water level in the pipeline.(2)Except that the stress in the corrosion area at the top of the pipeline decreases with the increase of the corrosion width and increases with the increase of corrosion depth,thestress in other parts increases with the increase of corrosion degree.No matter whether the performance of the concrete in the middle or bottom of the pipeline is degraded,except that the stress at the top of the pipeline increases with the decrease of the concrete strength,the stress of other parts shows a trend of increasing first and then decreasing as the concrete strength decreases.No matter the corrosion at the top of the pipeline or the degradation of the concrete performance,the degree of pipeline damage and cracking increases with the increase of the degree of pipeline defects.(3)As the shear wave velocity and Poisson's ratio of the soil around the pipeline increase,the pipeline stress gradually decreases,and the degree of damage and cracking also gradually decreases.Compared with the non-damaged pipeline,the defective pipeline is less affected by both.