Causes and counter-measures for exposed pipeline in frigid zone

Frost heaving, warping, soil erosion etc. can cause covering soil loss even pipeline exposure in frost soil, pipeline exposure caused by different reasons needs to be treated with different measures, so it is necessary to find out the causes first, then a specific measures can be formulated. Arch, warping and other permafrost disasters can cause bending and deformation of pipeline, but the pipeline subject to soil erosion will remain straight. A field detective method for the pipeline straightness which combines pipe locator and level instrument has been developed, this method can quickly find whether there is a bending in the pipeline by ground detection, without excavating pipeline and installing equipments. By analyzing two typical cases of exposed pipeline, it is found that settlement of pipe embankment caused by melting frost soil and soil erosion caused by water erosion are the main reasons of exposed pipeline in frost soil. In view of reasons of exposed pipeline in frost soil, measures such as dredging, change filling, refilling and construction of hydraulic work. According to different causes, the recommended procedures are put forward.