RU2370696C2 - Method for pipeline embedding - Google Patents

Abstract

FIELD: transportation.

SUBSTANCE: lengthy pipeline section with insufficient depth of embedding is opened below the lower generatrix and undermined, undermined section of pipeline is supported by pipelayers. At the bottom of trench, starting from the point of the last support of opened area, they installed supports filled with sand soil with fraction size of up to 5 mm - shells made of rot-resistant material, onto which a pipeline is laid. Height of shell supports is controlled by extent of filling and number of levels. After pipeline is laid on support shells, pipeline is padded, filling soil is padded and trench is backfilled with soil.

EFFECT: improving reliability of pipelines.

1 cl, 1 dwg

Description

The invention relates to the repair of pipelines, in particular, to a method for deepening a pipeline to a predetermined depth.

The sequence of work when repairing an underground pipeline is known from the description of the patent of the Russian Federation No. 2274792, “Method for repairing sagging and washed out sections of an underground pipeline”, IPC F16L 1/028, published on 04/20/2006, Bull. fig. No. 11, 2006.

The method is intended for use in the repair of main underground pipelines in the channels of small water barriers and consists in the fact that the pipeline is opened with the development of pits under it of the estimated depth and length, leaving supporting bridges, the pits are filled with bulk material, a trench under the pipeline is designed for the calculated value, and the supporting bridges are then cut off.

The method involves the removal of water below the level of the pipeline and the possibility of repair work. The method has a narrow scope, as indicated in the title of the invention.

The technological sequence of work and laying in the trench of a pipeline with uncontrolled deepening to a shallow depth is known from RD 39-00147105-015-98 “Guiding document. Rules for the overhaul of main oil pipelines ”, Ufa:“ Transtek ”, 1998, Typical flow charts for the overhaul of main oil pipelines, Appendix B, pp. 110, 111, 112, Fig. B4, B5, pp. 113, 114, 115 (prototype) .

In accordance with RD 39-00147105-015-98, when repairing long sections of the pipeline with replacement of insulation after opening the pipeline, undermining of the soil is carried out under the pipeline, repairs are being carried out.

To prevent sagging of the pipeline over an extended section, an open section of the pipeline to the insulation machine is supported by pipe-laying cranes equipped with trolley suspensions or towels.

The pipeline is supported by the indicated means only until the insulating machine. Immediately after the insulating machine, the pipeline is sprinkled with soil with its simultaneous compaction with tamping as the column moves from the supporting pipe layers and repair machines and the subsequent filling of the trench. The tamping does not provide the initial density of the soil and under the pipeline it remains looser than the natural state. As a result of this, as the pipe layers and repair machines advance, the pipeline shrinks to an indefinite depth, which depends on the physical and mechanical properties of the soil and the degree of compaction.

If the shrinkage depth exceeds the calculated one, stresses exceeding the permissible ones will arise in the pipeline and the pipeline may break.

The technical task of the proposed method is to ensure the laying of the pipeline at a given design depth, eliminating damage to the pipeline.

The implementation of the proposed method and the solution of the problem are possible due to the fact that in the method of deepening the pipeline with a given depth, including opening the pipeline below its lower generatrix, digging the soil under the pipeline, supporting the exposed section of the pipeline, if necessary, carrying out repair work, laying, dusting the pipeline, tamping the soil with powder and filling the trenches, the pipeline is laid on the trenches previously placed at the bottom, starting from the place of the last support of the exposed section along the way maintenance, supports - shells made of rotting material filled with sandy soil, the height of which is controlled by changing the volume of support - shells or the number of their tiers, while the strength of the supports - shells corresponds to the force acting on them of the laid pipeline and ensures its retention at a given depth and the possibility of re-digging under the pipeline, powdering the pipeline and tamping the soil with dusting is carried out only after laying the pipeline on the supports, then filling trenches and continue to open and deepen the next section of the pipeline in the same sequence according to the established technology. Features and advantages of the method are illustrated in the drawing, where in the drawing is a view of a pipeline laid in a trench with a recess (longitudinal section).

When repairing an extended section of a pipeline without lifting it, a usual set of works is performed: opening the pipeline 1 below its lower generatrix, digging the soil under the pipeline 1, supporting the exposed section of the pipeline is carried out by pipe-laying cranes 2 equipped with arrows 3 and soft towels 4.

If necessary, replace insulation after undermining to carry out a set of repair work. At the same time, towels are replaced with trolley suspensions and equipped with a mechanical column with special machines for repairing insulation. Further, starting from the last along the pipe-laying column, the trenches of the support-shell 5 are laid on the non-loosened bottom, as the pipeline is opened and the supporting pipe-laying machines move along the course of work, the pipeline 1 is laid on the support-shells 5 of a given height. The dusting of the pipeline 1 with the tamping of the soil and the filling of the trench is performed after it takes its place on the support shells 5.

In the case of deepening the pipeline without repairing the insulation, the supporting pipe layers 2 move cyclically, the rear pipe layer along the pipe moves forward the pipe layers.

In case of deepening of the pipeline during the overhaul with replacement of insulation, the pipe layers are equipped with trolley suspensions and move alternately or continuously, without changing the place in the column.

The support shells 5 are made of non-rotting material, for example, from bags in accordance with GOST 30090-93 and are filled with sandy soil in accordance with GOST 8736-93 with a fraction size of up to 5 mm.

At the same time, under the force action of pipeline 1, support-shells 5, natural-density trenches laid on an unbroken base, retain the height selected experimentally and ensure the preservation of a predetermined level of penetration of pipeline 1 during dusting and backfilling.

Shell 5 have sufficient strength and provide the possibility of re-digging under the pipeline 1.

The described method allows laying a pipeline with a given depth, eliminating the possibility of its destruction.

Claims (1)

The method of deepening the pipeline to a predetermined depth, including opening the pipeline below its lower generatrix, digging the soil under the pipeline, supporting the exposed section of the pipeline, repairing if necessary, laying, adding powder to the pipeline, adding dirt to the powder and filling the trench, characterized in that the pipeline is laid on trenches preliminarily placed at the bottom, starting from the place of the last support of the uncovered section during the course of repair work, supports - shells made of rotting material, filled sandy soil, the height of which is regulated by changing the fill volume of the support - shell or the number of their tiers, while the strength of the supports - shells corresponds to the force effect of the laid pipeline on them and ensures its retention at a given depth and the possibility of re-digging under the pipeline, adding powder to the pipe and tamping dusting soil is carried out only after laying the pipeline on the supports, then fill the trench and continue to work as the pipeline is opened in the same successive set of technologies.

Images