MECHANICAL ANALYSIS ON THE SAFETY OF GAS-TRANSPORTING PIPELINE CAUSED BY LANDSLIDE DEFORMATION

Geological hazards occurs frequently along the gas transmission pipeline project between Zhongxian city and Wuhan city,especially the medium to small size landslide due to be discovered difficultly or not be emphasized. The safety of the gas pipeline is seriously threatened by the landslides. Therefore,it is necessary to research the damage of the gas transmission pipeline caused by the landslides. Xiaodanziya landslide along the gas transportation pipeline between Zhongxian city and Wuhan city taken as an example,the paper discusses the common position and the mechanism relation between landslide and pipeline,establishes the mechanical model and discusses the factors of affecting the mechanical characters of pipeline. The research results are shown as follow: (1)the both ends and center of the pipeline is easy to be damaged by the sliding force of landslide,especially the both ends; (2)small landslide force q can cause the disadvantage state of stress of the gas pipeline. Therefore,the protection of the gas transmission pipeline needs to be paid more attention; (3)With the effect of Landslide,axial force on pipeline transform between tensile stress and compressive stress due to a change of pipeline to internal pressure and the result of operating temperature minus laying temperature.