RU2256838C2 - Pipeline for above ground lying - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: pipeline is lied on ground to define a Z-shaped profile in plane of supports made of trancated tetrahedral pyramids. A table is mounted on the top of the pyramid. The slots provided in the table receives suspension with axle that bears on the table. The axle prevents the pipeline yoke against moving down. The bearing rods of the pyramid extend from the table to the supporting plates secured to the beams which are lied on ground.

EFFECT: expanded functional capabilities.

3 dwg

Description

The invention relates to pipelines for overhead laying transporting liquids.

Known pipelines for overhead laying, zigzag in plan (see P.P. Petrov, V.V. Spiridonov. Overhead laying of pipelines. M .: Nedra, 1973).

The book shows a zigzag gasket on outriggers with the installation of fixed supports.

Suspended supports are flat swinging, they support the pipeline, and at the same time, the pipeline keeps the support from falling. Fixed supports massive, embedded in the ground.

The disadvantage of such gaskets is the low stability of the swinging supports, the high cost and the complexity of the fixed supports.

The aim of the invention is to increase the stability of the pipeline elevated laying laid in a zigzag pattern, especially with heaving soils, as well as in conditions of seismic activity.

This goal is achieved by the fact that all the supports of the elevated laying pipeline are suspended according to the truncated tetrahedral pyramid scheme. A suspension has been introduced into the slot of the table, the axis of which is supported by the table. The axis holds the suspension, to which the pipe clamp is fixed from below. The supporting rods from the table go to the base plates fixed to the bars laid on the ground or soil bedding.

The proposed device is shown in the drawings. Figure 1 presents the pendant support side view, plan, figure 2 shows a zigzag gasket in the plan.

Here L is the length of the zigzag, l is the distance between the suspension supports, θ is the angle of rotation of the gasket, f is the arrow of the bend of the pipeline.

The nozzles 2 are welded to the metal table 1, the nozzles are welded to the base plates 3. The racks are installed in the nozzles 4. The base plates are nailed to the bars 5. The suspension axis 6 rests on the table. The bottom suspension has a clamp holding the pipe 7. The suspension mounting allows it to deviate freely in all directions. The bars are laid on a leveling bed or directly on the surface of the soil.

Suspension supports in their scheme are a tetrahedral equilateral pyramid. All supports for this gasket are taken in the same size. The symmetrical support is easy to install. Its components can be manufactured at a construction base, and only installation is carried out on the highway. The supports of the proposed design work stably for vertical loads and overturning moment.

With any fluctuations in the temperature of the walls of the pipeline and internal pressure, the suspension does not go beyond the contours of the support. Calculations show that at maximum suspension displacement on an angular support, the holding moment exceeds the tipping moment by 3 times. On other supports, the ratio of the holding moment to the overturning moment will be even greater.

On the slopes of the mountains, the support bars are installed horizontally, for which soil cutting is done. The gasket design ensures stable operation in the most adverse permafrost conditions. The gasket remains stable under seismic activity. During earthquakes, the upper layers of soil are displaced horizontally. When the suspension supports are displaced, the pipeline on the suspensions will remain in place or shift by a small amount.

The longitudinal force from elongation of the pipeline caused by a change in the temperature of the pipe walls and internal pressure is determined by the formula

Bending moment at the top of the zigzag corner

The maximum stresses in the pipeline σ _C arise in the curved part. They are determined taking into account the most unfavorable combination of loads according to the formula:

where f is the arrow of the bend of the pipeline;

Θ is the angle of rotation of the gasket;

F is the cross-sectional area of the pipe wall;

σ _kc - annular stresses in the walls of the pipes;

E is the modulus of elasticity of the pipe metal;

W is the moment of resistance of the cross section of the pipeline;

I is the moment of inertia of the section;

α is the coefficient of linear expansion;

Δt is the temperature difference.

From the formulas it is seen that the zigzag angle Θ substantially characterizes the laying of the pipeline. It determines the ratio of the lateral displacements to the longitudinal elongations of the pipeline, as well as the magnitude of the elongation of the pipeline compared to a straight line.

With a decrease in the angle Θ, the stability of the zigzag pipeline decreases, the load on the supports increases. Significant displacements require the installation of large supports, the construction costs of which will exceed the savings received from reducing the length of the pipeline.

Studies have shown that at an angle Θ equal to 22-23 °, the pipeline stably works on internal stresses and external influences.

At Θ = 23 °, the route lengthens by 2% compared with the air line, which is significantly less than when laying pipes with U-shaped expansion joints. Moreover, the magnitude of the transverse displacements is small with sufficient stability of the circuit.

Claims (1)

The overhead pipeline pipeline is zigzag in plan, characterized in that all the supports are made in accordance with a truncated tetrahedral pyramid scheme with a table at the top, into the slot of which a suspension is introduced with an axis resting on the table and holding the pipe clamp from below, and the support rods from the table go to the support plates attached to bars laid on the ground or soil bedding.

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