METHOD TO INSTALL UNDERGROUND PIPELINE Russian patent published in 2013 - IPC F16L1/26 

FIELD: construction.

SUBSTANCE: invention may be used in areas of continuous and discontinuous distribution of permafrost soils (PFS) that subside when thawing. The method of underground pipeline installation in areas that subside as PFS are thawing consists in development of a trench and installation of a pipeline in it with subsequent filling. The permissible bend profile is generated by filling of soil prisms on the surface and along the length of the pipeline with the distance not exceeding beam span, with height determined by calculation and increasing in direction from stable or low-subsidence soils to subsidence ones. Besides, prisms are arranged at both sides from the pipeline above the thawing halo, with the distance between them that is not more than the external diameter, which due to subsidence are submerged as soil is heated, compacted, and further subsidence of the pipeline is excluded. Prisms have top length of at least 3 metres, width of 1.5 external diameters of the pipeline, but at least 1.5 metres, and slops, depending on properties of the filled soil, but at least 1:1.25.

EFFECT: increased operational reliability of a pipeline.

4 dwg