Study On Stress-strain Model Experiment Of Raw Water Pipeline Under External Loading

With the rapid development of China’s economy,the utilization rate of underground space in various regions is increasing,and the underground pipe networks becomes more complicated.During the construction process,the phenomena,such as,overloading of construction vehicles and short distance stacks often come out.The additional deformation and stress endanger the normal operation of pipelines,even the destruction of underground pipelines reduced.At present,there are ambiguities and lags in the protection criterion of raw water pipelines in most parts of China,which cannot meet the needs of the current pipeline operation.Therefore,it is particularly important to study the mechanical characteristics of buried raw water pipelines under the external loading,which has an important dominant role and practical significance for ensuring the safe operation of raw water pipelines.This article uses the method of indoor physical model test to study the mechanical characteristics of the raw water pipeline under loading conditions.Then,the three-dimensional numerical simulation software is used to verify the stress-strain model test results of the raw water pipeline,and the detailed stress analysis of the raw water pipeline is performed in order to provide some basis for the protection of the underground pipeline.The main research work includes:1)The operational status of the raw water pipelines in China are analyzed.The discussion about the potential damage of buried raw water pipelines by stacking is carried out.At the same time,the research status on the impact of ground stacking on pipelines at home and abroad is summarized.2)The inverse calculation formulas of the results of the physical model test and the actual conditions are derived considering various similarity ratio indicators based on the similarity design principle of model tests.3)By designing the physical model test,the mechanical characteristics of the raw water pipeline are studied under loading conditions based on the results of the model test.The influence of various loading conditions on the pipeline stress is investigated by analyzing the axial and hoop stress changes of the pipeline.Furthermore,it can be concluded that the changes in the loading distance,the loading height,the buried depth of the pipeline and the diameter of the pipeline are the main factors that cause the stress changes of the buried raw water pipeline.4)By comparing and analyzing the results of the physical model test in and three-dimensional finite element numerical simulation,it is found that the numerical results are in good agreement with those of the model test,that demonstrates the reliability and accuracy of the model test in this paper.The mechanical characteristics of the raw water pipeline were further analyzed considering more conditions.5)Based on the analysis of the stress characteristics of the buried raw water pipeline under the external loading,the deformation property of the buried raw water pipeline caused by factors such as the loading distance,the loading height,the buried depth of the pipeline and the size of the pipe diameter are summarized,and the corresponding suggestions of pipe protection measures and recommendations are put forward.