Strain-based Long-distance Pipeline Design Technology

With the rapid development of China's economy and the increasing demand for natural gas in China,China has come to the climax of the long distance gas pipeline construction.Due to the long distance of long-distance gas pipeline construction,it is inevitable to suffer a variety of geological disasters,such as landslides,faults and debris flow disasters.In this paper,the mechanical characteristics of buried pipelines under landslide,fault and debris flow are analyzed by means of numerical analysis and calculation based on non-linear analysis theory,such as literature and disaster analysis,and the guidance method based on strain design is proposed.Design to provide theoretical reference.The main contents of the paper are as follows.(1)Taking the low carbon steel(L245,L360)pipeline as the research object,the mechanical response characteristics of the pipe under various load were measured by mechanical experiment,and the mechanical analysis model of the pipeline was established.?According to the provisions of the national standard,test the mechanical properties of experimental pipe parameters;?Combined with numerical simulation analysis,the experimental plastic deformation test and blasting test were carried out to obtain the experimental data of quantitative plastic deformation and pipe residual strength under different load.?To study the distribution and residual strength evaluation method of quantitative plastic deformation under different load,and to establish the mechanical model of pipeline mechanics.(2)Taking the low carbon steel(L245,L360)pipeline as the research object,the complicated load state of the oil and gas pipeline in the construction and service stages is clarified,and the mechanical response characteristics of the oil and gas pipeline under the harsh condition are analyzed.Of the design technology,combined with the actual project to verify.?The safety reliability design technique based on fracture mechanics and reliability theory under four kinds of limit conditions under different load conditions,strain limit,applicability limit state,extreme limit state,fatigue limit state and accidental limit state.?the allowable strain determination technique based on the properties of pipe and the structural integrity under the maximum strain condition;?through the earthquake fault zone pipeline seismic based on strain design technology.