SU1333927A1 - Method of laying pipeline underwater reducer - Google Patents

Abstract

The invention relates to the construction and can be used in the construction of the underwater crossing of the pipeline through water barriers, having a channel part and two floodplain slopes. The aim of the invention is to reduce the cost and labor intensity of ballasting the subsea pipeline due to the fact that using ring-shaped detachable weights only ballast the channel part of the pipeline, and after dragging the pipeline, the floodplain sections of the pipeline are superimposed. 1 il. o (l

Description

The invention relates to the construction and can be used in the construction of the underwater crossing of the pipeline through water barriers, having a channel part and two floodplain slopes. about

The purpose of the invention is to reduce the cost and labor of ballasting the underwater pipeline crossing by reducing the number of ring rings used.

The drawing shows laid pipeline transition.

The method is carried out as follows.

An underwater trench is developed in the channel part of the waterway 1 of width L, as well as on floodplain slopes with a width of 1 °. Mounted, welded, insulated, tested and lined pipe 2, then it is ballast to a level of negative buoyancy (design ballasting) on the section corresponds to the width L of the channel part of the water course

1, and the plots that are located on floodplain slopes with a width of 1 are left unbalanced. For this, the lower parts of the upper section 3, annular cast-iron or annular reinforced concrete are laid out along the channel section, and then a pipeline is laid on them using pipe layers.

2, above the lower parts

3 install the upper ones and fasten them. At one end of the pipeline 2 install the head end 4.

After that, using the trench - on the floodplain slope as a descent path, the pipeline 2 is pulled through with a winch (not shown) mounted on the opposite floodplain slope, and a cable attached to the head

4 pipeline 2. During the dragging, the pipeline section with a length corresponding to the width L, ballasted by the design amount, is plunged to the bottom of the underwater trench of the channel part of the waterway 1, and the floodplain sections of the pipeline corresponding to the width 1, free from the supply 3, are afloat and develop S-shaped curves with ballyastirovannom site.

Dragging is carried out until the pipeline section 2 of the ballasturized ring is completely matched.

five

five

0

0

five

0

45

50

55

Zheletel MI 3, with the profile of the channel part of the watercourse 1 wide L.

With a very large width of the watercourse (up to 2000 m) in order to carry out the operation of pulling through the pipeline 2, a significant part of which is ballasted to the level of negative crying, powerful traction means are required. In this case, to ensure dragging, this section of the pipeline can be divided into several parts and ballasted sequentially, the section being towed. At the BTO stage, ballasting of the floodplain sections of the pipeline, located after towing in trenches on the floodplain slopes filled with water from the watercourse 1, is completed; pipeline 2 with water, after which it is immersed at the design marks.

Depending on the water level in watercourse 1 (low or high) and, accordingly, in trenches on floodplain slopes, two options for ballasting pipeline sections on floodplain slopes are possible: without pumping out water from trenches and with pumping out water.

With a low water level in the trench waterway on the floodplain slopes, the water in the trenches is not filled to the full depth, so the water in the trenches does not interfere with the visibility of the ballasting work, and in this case it is advisable to carry out the second ballasting step after submerging the pipeline sections to the design marks without pumping out water from the trenches.

With a high level of water in the watercourse 1 at the beginning of the trenches on the floodplain slopes, earth bridges 5 are arranged and the water is pumped out of the trenches, thereby ensuring good visibility of the front end of the ballasting operation.

At the second stage of ballasting the sections of pipelines 2 located on the floodplain slopes, it is advisable to use ut desires for a simpler and cheaper construction, for example, of the concrete covering type (UBO), which are placed on the pipeline with a free overlay on top. Then the pipeline is covered with soil and the soil is compacted.

Ula Invention Form

The method of laying the underwater pipeline transition, which consists in welding lashes into the pipeline with a length equal to the length of the channel and floodplain sections of the transition, ballasting it with ring-shaped detachable weights to the design negative buoyancy, with the exception of the head section, dragging with a weave

the head sections along the bottom of the underwater trench, characterized in that, in order to reduce the cost and labor of ballasting, the last one is carried out on the pipeline section corresponding to the channel part of the watercourse, and the floodplain sections of the pipeline are ballastised by free application of the desired material after it has been dragged.

Editor M.Dshyn

Compiled by V. Kopaev

Tehred M.DidykKorrektor S.Cherni

3943/34

Circulation 811 Subscription

VNIIPI State Kotttn & Ta USSR

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk .ab. 4/5

Production and Printing Enterprise, Uzhgorod, st. Project, 4

Claims (1)

SUMMARY OF THE INVENTION A method of laying an underwater passage of a pipeline, which consists in welding the lashes into a pipeline with a length equal to the length of the channel and floodplain sections of the transition, ballasting it with ring detachable weighting loads to the design negative buoyancy, with the exception of the head section, pulling with floating head sections along the bottom of the underwater trench characterized in that, in order to reduce the cost and laboriousness of ballasting, the last ice is carried out in the pipeline section corresponding to the channel of the watercourse, and the floodplain sections of the pipeline are ballasted with a free 10 overlay of weighting materials after dragging it. Compiled by V. Kopaev Editor M. Dylyn Tehred M. Didyk Corrector S. Cherni Order 3943/34 Circulation 811 Subscription VNIIIPI of the USSR State Committee for Inventions and Discoveries 113035, Moscow, Zh-35, Raushskaya nab., 4/5 Production and printing company, Uzhhorod, st. Project, 4