Study On The Dynamic Model Of Soil-Pipe-water Interaction For Buried Pipelines Under Earthquake

The main part of the city lifeline project is buried water-supply pipeline,it's closely related between people's daily production and quality of life.The people's lives and property is under threat of buried water-supply pipeline damage and the secondary earthquake disaster especially in Chinese frequent earthquake zone.Therefore,it is of great theoretical value and great practical significance to improve the seismic performance of the buried water-supply pipeline and ensure the normal operation of the water-supply pipeline.The paper deals with the axial stress of the buried water supply pipeline under the earthquake considering the interaction effect of soil-pipe-water,which is based on the tube-soil interaction model and the tube-fluid interaction model.And the ADINA value Simulation has been taken to verify the reliability of the study.The main contents and analysis results of this paper are as follows:1.The action of buried pipeline dynamic model has been derived ignoring the role of water in the pipeline and taking into account the role of the pipeline under the action of the pipe-soil.The fluid-solid interaction dynamic model of the water supply pipeline under the earthquake action has been deduced,which is ignored the role of soil against the buried water supply pipeline and taken the traveling wave method to consider the fluid-solid interaction effect of the water supply pipeline under the action of the earthquake;Based on the dynamic model of buried pipeline under earthquake action and the fluid-solid interaction dynamic model of water supply pipeline under earthquake action,the soil-pipe-water interaction of buried water supply pipe under earthquake action is studied by traveling wave method.The dynamic model of soil-pipe-water interaction in buried water supply pipeline under earthquake action is put forward creatively.2.The ADINA finite element software was used to establish the buried pipeline soil-tube model under the action of earthquake.The axial stress of the pipeline under different buried depth,pipe diameter and wall thickness was calculated.In tube-soil model,the axial stress increases with the diameter of the pipe,when the seismic intensity of the seismic wave is 8 degrees.And the axial stress increases by 23.16%when the pipe diameter is 1400mm.Meanwhile,the axial stress of the pipe decreases with the increase of the wall thickness.When the pipe wall thickness is 5mm,the axial stress is larger than 35.77 percent compared with that is 25mm.When the pipe depth is deepened,the axial stress of pipe increases firstly and then decreases.And the axial stress of the pipe reaches the maximum of 2.85MPa when the depth is 2m or 3m.3.The ADINA finite element software was used to establish the buried water supply pipeline soil-tube-water model under the earthquake.And the axial stress of the pipeline was calculated under different buried depth,pipe diameter and wall thickness.In soil-tube-soil model,the axial stress increases with the diameter of the pipe,when the seismic intensity of the seismic wave is 8 degrees.When the diameter is 600mm,the axial stress is 3.01 MPa.While the diameter increases to 1400mm the axial stress is 4.00MPa.With wall thickness in the soil-tube model increases,the axial stress decreases.The axial stress decreases from 3.53MPa to2.78MPa,while the diameter increases from 5mm to 25mm.With the increase of the depth from 0.5m to 4m,the axial stress of pipeline increases from 2.84MPa to 3.19MPa.4.By comparing the buried pipe model under the earthquake and the buried pipe model,the results show that the axial stress of the buried water-supply pipeline model is much larger than that of the buried pipeline model under different buried depth,pipe diameter and wall thickness.In soil-tube model,the axial stress of pipeline is more steep,while that is more gentle in soil-tube-water model.5.Combined with the engineering example,it is found that the design pipe axial stress results of the soil-tube model are smaller than that of the soil-tube-water model in seismic design.Therefore,the role of water in earthquake can't be ignored in seismic design.The conclusions obtained can provide a theoretical basis for the analysis of the damage mechanism and damage development mechanism of the buried water-supply pipeline structure along with soil-tube-water interaction.Meanwhile,it also solve the theoretical problems related to the earthquake disaster in the safe operation of the buried water supply pipeline.