Pipeline laying method of long-distance coal conveying pipeline

Abstract

The invention discloses a pipeline laying method of a long-distance coal conveying pipeline. The method comprises the following steps that A, a pipeline is imbedded below a frost line, and an earth covering depth from the top of the pipeline to a natural terrace is not less than 1.0 m; B, when the pipeline is laid in a gravel area, the over excavation of 0.2 m is required, a fine earth or fine sand cushion layer which is 0.2 m thick is first paved necessarily at the bottom of a trench, and then, the pipeline can be lifted to be put in the trench after the fine earth or fine sand cushion layer is flat, when the trench for the pipeline in the gravel area is backfilled, the trench is first backfilled to 0.3 m above the top of the pipeline necessarily by using fine earth (sand), and then, the trench can be backfilled by using original earth, the maximal grain size of the backfilling fine earth is not more than 10 mm, and gravel blocks as the backfilling earth are not expected to be more than 250 mm; and C, accident cutoff valves and valve chests are arranged at two ends of the pipeline traversing a large river and at proper positions along the pipeline, and the pipelines within at least 50 m outside outer edge lines of two ends of the pipelines traversing large and medium rivers and gullies are expected to adopt a way the same as a traversing section. Not only is the wear to a pipe wall in a construction process reduced, but also the maintenance cost of the pipeline in a process that the pipeline is used for conveying coal slurry is reduced.

Description

technical field [0001] The invention relates to a pipeline laying method, in particular to a pipeline laying method for long-distance pipeline coal transportation. Background technique [0002] For large-diameter slurry pipelines with a diameter of more than 600mm, the laying operation usually adopts the staggered and parallel operation mode of "ditching and laying pipelines" and "pipeline group butt welding". Taking the laying position corresponding to a single pipe as a pipe station, the operation sequence is: lay the pipe first, then open the ditch, then weld the single pipe in a team to form a pipe section, and then backfill the ditch under the pipe section, so staggered conduct. Backfilling in this operation method is very rough, without strict control, causing great damage to the pipe wall, and increasing the later maintenance costs of the pipeline. Contents of the invention [0003] The purpose of the present invention is to provide a kind of pipeline laying metho...

AI Technical Summary

Problems solved by technology

Backfilling in this kind of operation method is very rough, without strict control, it will cause great damage to the pipe wall, and increase the later maintenance costs of the pipeline.