The Influence Of Oil And Gas Pipe Laying Methods To Slope Stability Study

At present,the total length of oil and gas pipeline accumulated over 120000 kilometers in china and it has become the second longest country in the world.At the same time,the one/two/three line of “west-east gas project” was completed and most of the pipeline distribution in the loess plateau region,such as Qinghai/Gansu/Shaanxi.These are many mountain hills and other complex geological situation in this region,the pipeline laying must to encounter many of large slopes.This study begins from pipeline geological hazards investigation,and analyzed the characteristics of water logging/the collapse,landslide hazard of slope.Based on the finite difference method,it has established various slope stability analysis model under various types of conditions by finite element analysis software named FLAC,and analyzed the shear strain rate,horizontal displacement,safety coefficient and other indexes of the slope under many kinds of working condition,the results showed that:(1)the most important factor of horizontal pipe laying(to slope laying)is position.When the pipeline is located on the sliding surface,the safety coefficient is reduced,and when the pipe is located on both sides of the sliding surface,the safety coefficient almost has no affected.(2)the most important factor of horizontal pipe laying(to slope laying)is the angle which between the pipe and the slope.With the gradual increase of this angle,the slope safety coefficient decreases gradually,but it still greater than the original slope.In terms of the stability of the slope,the longitudinal laying of the pipeline is favorable,but meanwhile,the stress of the pipeline is increase.(3)Through analysis a case of slope reinforcement engineering in a mining area,it has been proved the applicability and reliability of prestressed anchor cable be used in the reinforcement engineering of oil and gas pipeline slope.After reinforcement,the level of the vertical displacement around the pipeline slope is decreases,and the stress around the pipeline is more reasonable,the whole slope stress and displacement has been greatly improved.This research is based on the actual needs of the slope engineering of oil and gas pipelines,focusing on the influence of pipe laying method on slope stability,at the same time.Through analysis a case of slope reinforcement engineering,it gives some suggestion of strengthening and protection.