Study On Pipe Soil Interaction In Geological Hazard Prone Area Of Complex Mountainous Area

With the continuous development of social economy,China's demand for oil and gas is also increasing.Long-distance pipelines often cross hundreds or even thousands of kilometers,and inevitably cross some complex mountainous areas,where geological disasters often occur due to the nature of rock and soil and geological structure.When the geological disasters are serious,the soil around the pipeline will be displaced and deformed in a large area,and the pipeline will be bent and deformed under the action of the earth pressure around the pipeline,which will affect the safety of the pipeline and even damage the pipeline,resulting in the oil and gas can not be transported normally.However,due to the different properties of pipeline and soil,there is interaction,which leads to the deformation of pipeline and soil under the action of geological disasters.Therefore,it is very important for the safe operation of pipelines to study the mutual deformation law of pipe and soil under the action of geological disasters.Relying on the ground gathering project of a certain gas field in Sichuan,taking the engineering geological conditions in the study area as the geological background,and on the basis of analyzing the failure forms and causes of long-distance oil and gas pipelines under various geological disasters in mountainous areas prone to geological disasters,this paper establishes a pipe-soil coupling numerical calculation model under geological disasters,analyzes the causes of various geological disasters and their impacts on buried pipelines,and makes a detailed study on the pipeline deformation,soil deformation around the pipe and the distribution law of soil pressure around the pipe during geological disasters.By collecting the investigation data and existing research results of geological disasters in the study area,this paper studies four kinds of geological disasters in the study area,analyzes their formation mechanism and characteristics,evaluates the impact caused by pipelines,selects typical geological disaster points for analysis,and studies the landslide,ground subsidence,collapse and water damage in the study area.By comparing numerical simulation with field monitoring data,this paper studies the stress,strain and displacement characteristics of transverse crossing pipeline under the action of landslide,and draws some conclusions: the stress of pipeline is concentrated in the slip boundary area,and the displacement of soil tends to be slow first and then sharp.Through the combination of indoor model test and numerical simulation,the stress and strain characteristics of pipeline under the action of ground subsidence are studied,and the results are as follows There are 69 figures,11 tables and 73 references in this paper.