| Landslide hazards are becoming more and more serious due to the complex topography along the long-distance pipeline.When landslide occurs,it will cause bending deformation,local folds even pipeline fracture,which will have a very negative impact on the safe operation of pipelines.In this paper,the mechanical behavior of pipelines under different landslides,the influence of different factors and the implementation of pipeline remote monitoring system are studied,which can provide theoretical basis and technical support for the design,construction and operation management of pipelines in landslide areas.Firstly,according to the formation conditions and classification methods of landslides,the characteristics of stress and deformation of pipelines under different landslides are studied.Based on the theory of elastic foundation beam,the analytical formulas of mechanics under pipeline landslide are deduced,and the effects of various factors on the internal force state of pipeline under actual landslide are discussed.The slip force and the width of the landslide have a significant effect on the stress of the pipeline.Secondly,considering the large deformation of pipeline and the material nonlinearity,the nonlinear soil spring is used to simulate the pipe-soil interaction,and the finite element mechanical analysis model of buried pipeline in landslide area is established.The deformation and stress law of pipeline under different landslides are studied,and the influence of different factors on stress and strain of pipeline is discussed.The study shows that the dangerous area of pipeline under transverse landslide is located in the transition area between landslide and sliding bed at both ends,while the dangerous area of longitudinal landslide pipeline is located in the transition area between landslide and sliding bed at both ends.With the increase of landslide displacement,pipeline depth and soil cohesion,the stress and deformation of pipeline will become more and more obvious,and the increase of pipeline wall thickness can resist the deformation of pipeline.Through the comparison between the field monitoring data and the finite element simulation results,the feasibility and accuracy of the monitoring scheme are verified.Finally,through the investigation of landslide geological hazards on site,combined with the actual situation of gas pipeline in the landslide area,an automatic monitoring system of pipeline stress and strain is designed and applied in the landslide area of pipeline.Monitoring data shows that the system can evaluate the safety of pipelines in landslide area,improve the ability of landslide disaster warning,and ensure the safe operation of oil and gas pipelines. |
