BNH Pipeline Geological Hazard Characteristics And Evaluation Application Research

BNH pipe mainly undertake the task of natural gas transmission.Since its launched the gas field construction in 2012,has the capacity of transporting 24 million cubic meters of natural gas per day.It expected to be built 11 billion cubic meters the ability of natural gas ability in 2016 at the end of December.Pipe pressure,flow rate will be in high operating conditions,and carry out risk assessment of geological factors,semi-quantitative risk assessment on the BNH pipe.Provide evaluation basis and decision-making basis for prevention and safe operation of pipeline geological disasters.This paper has carried on the BNH pipeline geological disaster characteristics and the geological disaster risk qualitative evaluation based on the research status of domestic and international geological disaster risk assessment theory,method,field investigation,and data compilation.Select the typical geological disasters that have great influence on the safe operation of pipelines under the current conditions:collapse,landslide,and unstable slopes,and carry out geomechanical analysis of geological disasters in the pipeline.Analysis of dangerous rock collapse mechanics is mainly to slippage,dumping and fall dangerous rock mass in the stability analysis under different working conditions,and quantitative analysis of collapse of ground distance,rock fall velocity,height of jumping,rock fall energy,and rock fall impact force,using software Rocfall to simulate the rock fall collapse.Landslides and slope instability geological mechanics analysis of the pipe,through numerical simulation for slide and retrogressive two kinds of typical landslides in slide force,and determine the stability of the landslide,on the elastic foundation beam theory analysis of piping stress and displacement.The geological disaster risk assessment including regional pipes liability geological pipeline risk assessment,geological evaluation and monomer pipeline risk of geologic evaluation,which use factors superposition method,normalization method and the golden section method to determine the region pipeline geological factors susceptibility zoning,qualitative evaluation method and semi-quantitative evaluation method were used to evaluate the geological risk of single pipe pipeline from risk probability evaluation,failure consequence evaluation and risk matrix.The geomechanical analysis conclusions of geological disasters in the pipeline can be applied to the actual project,the smaller the pipeline coating internal friction angle,the smaller the pipeline by the impact,the greater the coating thickness,the smaller the pipeline by the impact.Pipeline routing process,the specific nature of the landslide,avoid the landslide thrust clusters,can effectively reduce the threat of landslide thrust of pipeline.The width of landslide,the greater the force of pipeline was,the greater the can determine a threshold,if in the same area,when landslide width greater than the critical value,should carry on the protection,can effectively guide the project.