The Study Of The Comprehensive Partition About The Geological Hazard Of The Longgang-xixia Branch Pipeline Project

The West-East natural gas transmission second pipeline project has been a key engineering of state super large enterprise.The pipeline network can be divided into 1arterial pipeline and 6 feeder pipelines,with a total length of 8036 km.Longgang-xixia feeder pipeline is one of the West-East natural gas transmission second pipeline project.It starts from Longgang gas reservoir of renshou county of Sichuan province, from northeast through pingchang county,t ongjiang county,wanyuan city of Sichuan province and zhenba county,z iyang county,h anbin district,xunyang county,shangnan county of shanxi province and xichuan county of henan province to end by the dongwan of chongyang township of xixia county of henan province and join arterial pipeline in this area.The general trend extends southwest to northeast. The overall length of the pipeline is 610 km. It threatens greatly to the pipeline construction and the security operation by the changeful geological and environment conditions and various geology disasters. After the geological disaster risk appraisal may learn various geology disaster distribution and developmental mechanism from the pipeline along the route and predict the potentially suffered damage after the pipeline construction and operation and provide the disaster prevention,reduction and evadion basis for the pipeline construction, and provide the safeguard to ensure the pipeline security and reduces the economic loss.Therefore,the study of the comprehensive assessment about the geological hazard of the Longgang-xixia arterial pipeline project has the guiding sense to the constructions and the security operation of the West-East natural gas transmission second pipeline project. Simultaneously,it can be used for reference by the fatalness assessment of geologic hazard of the long distance pipeline project of the other suffering various geological disasters.Thesis of the study area the first geo-environmental conditions in disaster-site investigation, laboratory analysis studies, especially the active faults along the pipeline, including: the southern margin of Qinling deep fault, Lintan - Sanyo deep fault, Shiquan -- well-being of deep fault, the city population - such as deep fault Housing County. Initially on the buried pipeline across the fault of the earthquake response, the regional tectonic setting and structural system, and thus carried out along the active fault investigation and evaluation activities, to draw along the active faults are in a state of weak activity. Finally, the process pipeline, in response to active faults or earthquake seismic measures proposed by the project.Through on-site investigation and data collection analysis, research and development section of the main types of geological disasters, landslides, avalanches (rock), landslides and slope instability in four types of potential, mainly located in Longgang - Xixia branch of the bus route in the preceding mountains, the middle section of the Han River Valley and later to the territory of the new county mountain ridge. The assessment found a total of investigation and assessment of pipeline within the scope of 195 geological disasters, including 29 landfalls, 146 landslides, 16 mud-rock flows, 6 unstable slopes.Above all,this paper studies the regional geological environment condition to carry on the investigation of the scene geological disaster and the indoor analytical study.It finds out the type of the assessment regional geological disaster and studies on the formation conditions and influencing factors.Therefore, it can be regarded as an assessment index by the density of the distribution of disasters and the scale of the disaster and the geological structure and the lithologic characters and the topography and morphology and the human engineering activities and so on. According to the geological disaster risk,it divided into large, medium and small third-level to determinate the classification the standard.The assessment regional has been divided into many assessment units, the utilization of the fuzzy mathematics theory and the extension theory carries on the geological disaster risk overall assessment to various units and districts along the route according to the appraisal result to the pipeline.Carrieing on the contrast the fuzzy mathematics appraisal result and the extension method appraisal result, we discovered that two kind of appraisal method obtained result tallies basically except for partial existence difference, appraisal result and actual situation conform to common. In addition, according to the extension method measure results, we not only may obtain the concrete district result, but may also act, according to its rank variable characteristic value to understand the appraisal result the deviation degree and causes the geological disaster risk appraisal result to be more accurate concretely.