Types and application of pipes in construction. Do-it-yourself columnar foundation made of pipes: metal pipes

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The construction of pipes is prohibited if there are ice and ice drifts. On streams and rivers that have fish spawning grounds, the installation of pipes is possible only with the permission of the fish inspection.

Elevation of the edge of the soil sheets on the approach to the pipe above the calculated level water base not less than 0.5 ma is taken, and for a pipe having a pressure or semi-pressure mode, not less than 1 ma.

The pipe heads are constructed from portal walls and a pair of sloping wings, which are buried in the soil base below the freezing depth by 25 cm and are installed on a base of crushed stone materials with a thickness of 0.1 mA.

The natural earth below the freezing depth is replaced with a mixture of sand and gravel.

Pipes are divided into 3 groups according to their bearing capacity: the calculated height of the soil backfill is 2 m, 4 m, 6 m.

Valid for certain conditions construction of pipelines using pipes with other design heights and backfills.

Pipe grades consist of alphanumeric groups separated by hyphens. In this case, the first group contains designations of types, and the second - diameters in centimes and useful length in decims, as well as numbers of groups according to bearing capacity.

The construction of pipes takes place in accordance with GOST 26633 from heavy concrete mixes, where the compressive strength class B 25 is established. The concrete water resistance of the pipe must comply with W4.

Pipes TS, TB, TSP and TBP are supplied to consumers complete with sealing rings made of rubber material. Cracks on pipe surfaces are unacceptable, with the exception of a shrinkage width of not more than 0.05 mm.

Pipe heads with openings of 0.5 ... 0.75 m are constructed from portal walls that are buried in the ground below the freezing depth by 25 cm.

Slope wings can be made of a B15 grade monolith without reinforcement and taking into account the formwork size of the precast concrete block.

The length of the pipes (Ltr) is determined using the formula:

Ltr \u003d in + 2 (n-s-d) xm,

where in is the width of the earth in max;

n is the bulk height in max;

c is the wall thickness in max;

d - pipe opening in max;

m - coefficient of sloping foundations.

Construction technology of reinforced concrete pipes (reinforced concrete culvert pipes)

Before installation, it is necessary to carefully check the pipes for permissible deviations in accordance with GOST.

Check pipe elements for permissible deviation according to GOST (link length is 0-1 cm, wall thickness is 0.5-1 cm, other measurements are approximately + 1 cm).
Remove sags, concrete splashes on the connecting link elements.
Select all pipe elements by brand according to the project decision.
Store pipe elements in one place.

Preparatory work on site:

Select and prepare a site for construction. Uproot the shrub and plan it with the necessary equipment.
Accept and place material, equipment and structures in specific locations.
Break the axis of the pipe and the excavated contour.

Geodetic work that is carried out in the construction process usually includes:

arrangement of the structure in plans, taking into account the main axes and contours of the pit;
altitude breakdown;
leveling of longitudinal profiles of pipe trays.

The device in the plans occurs with the fixing of visible signs in place, by which it is possible to accurately determine the location of the pipe and its constituent elements. Fastening usually takes place with the help of two pillars, which are installed along the longitudinal axes of the pipes, in order to ensure their safety for the entire construction period, and pegs driven along the bulk axes in the necessary places.

In some cases, at a distance of 150-200 cm from the border of the pit, cast-off boards are built horizontally, on which characteristic foundation points are marked. The boards themselves are nailed to poles that are fixed to the ground.

With a planned breakdown, a strict exposure of the alignment position is needed, which is located along the axes of the embankments.

If any unfavorable soil or other factors are identified at the locations of pipes and heads, their displacement in the required direction is required. All differences from the existing project must be agreed with the design organizations and the customer, as a result of which the most appropriate technology will be selected.

High-rise technology is to determine the surface marks at the locations of the pipes and the depth of cutting the earth or, conversely, its filling under the pipes. Soil work related to digging a foundation pit and arranging a foundation is carried out in the presence of instrumental control.

With the help of a level, the compliance with the project of the actual mark of the excavated bottom to the pillow top is checked. In a similar way, the height positions of the foundation are controlled, and later on, the installation of pipes and heads.

The longitudinal profiles of the pipe are leveled immediately before backfilling and backfilling of the bulk layer to the marks according to the project. Necessary, periodic and continuous further observations are established in accordance with the required standards.

This technology is produced with binding to benchmarks, which are located near the pipes.

Execution work

The pit is obtained using an excavator.

Excavator digging and manual cleaning of pits.

The device (if necessary) of the excavated bottom with stone material by pressing with the help of drowning tools.

The pit for the foundation, where the culverts will be located, is developed mainly without fences (fasteners). Only in water-saturated soil, with significant inflows of water and the impossibility of ensuring the stability of the walls of the pit, the earth is developed taking into account the fixing protection. Strengthening the pits is applicable if there are operated structures nearby. This technology ensures their stability.

Pit outlines and the technology of their development depend on the construction of pipes and their foundations, on the types and conditions of the earth. The steepness of the slopes of the pit is assigned taking into account the depth of the pit and the characteristics of the developed land.

If the design provides for waterproofing or other work is performed that is associated with the presence of people here, then the distance between the side surfaces of the foundation and the vertical walls of the pit is applied at least 70 cm. When there are no such works, these pairs can be reduced to 10 cm.

In case of foundation concreting without formwork, the excavated size is taken equal to the size of this foundation.

When excavating pits with slopes, the gap between the foundation and the bottom of the slope must be at least 30 cm. When digging a pit, measures are taken to prevent filling them with surface or ground water. For these purposes, earthen ridges are poured along the pit contours. When constructing pipes on permanent watercourses, it is necessary to make a dam or divert the channel to the side with a ditch.

If water nevertheless got into the pit, it must be removed or a descent into the ditch should be arranged below. This is usually possible during the construction of a slope water supply system or mechanized drainage. In these cases, enclosed pits are made at the bottom of the pit, from which water is pumped out using a pump. Such pits are located behind the foundation contour. They provide drainage during work with the foundation, up to the backfill.

As the pit deepens, the pit fence must be lowered. Soils of non-rocky rocks are developed by earth-moving machines without disturbing the natural composition of soils in the foundations. The shortfall is 10-20 cm. The final cleaning of the pit takes place before laying the foundation.

To date, of the various earth-moving machines, bulldozers and excavators are the most widely used in the construction of water pipelines on roads and railways.

The bulldozer is most popular when arranging pits.

Pit construction by bulldozers is most appropriate when laying the pipes themselves and heads at the same level or if there are minor differences.

For a pit that is not fenced, an excavator is used that has a backhoe or dragline. The advantage of this mechanism is the ability to develop soil at different depths, which helps to ensure the construction of pits under the middle parts of pipes and heads, the foundation soles of which are laid at considerable depths.

When developing a fenced pit, it is advisable to use grabs.

In all situations, the excavated soil is placed outside the excavation at distances that can ensure the stability of the walls or fences. Heaps of earth should not interfere with the construction, installation and water flow.

The device and construction of the foundation

There is a small-clastic and large-block foundation.

When mounting the foundation using prefabricated elements, you first need to lay the head blocks to the sole level. Then, the sinuses of the foundation heads are filled to the same level. Subsequently, from three sides they are covered with local soil, and in places where foundations of different depths are mated, with sand-gravel or sand-gravel mixtures, which must be compacted in layers and poured with cement mortar.

Then the foundation masonry and heads must be carried out taking into account the sectional. Consistent construction is required, from the output heads to the input ones. Multi-row masonry is performed using suture dressing. For the installation of a monolithic foundation, you need:

fabricate and install formwork;
deliver ready-mixed concrete or prepare it on site;
lay the mixture
provide the necessary care, remove the formwork, fill the sinuses.

The simplicity of the outlines of the foundation allows you to make formwork in the form of an inventory board, which is used at many construction sites. The surfaces of such shields must be smooth. Before concreting, they are recommended to be lubricated with grease. This will later help to more easily separate the shields from the concrete structure.

In order to load the concrete mixture into the sectional formwork, it is necessary to use inventory trays or buckets, which are loaded on site or delivered from the concrete mixing unit. Compaction of concrete occurs with the help of deep or surface vibrators.

The device of a prefabricated monolithic foundation occurs in the following sequence: it is required to install the formwork between the sections on the prepared base or pillow, pour the concrete mixture into the available space.

The requirements for the production of concrete work are the same as for the installation of a monolithic foundation. Mechanisms and equipment for foundation devices must be selected taking into account all technological processes for the construction of pipes.

An approximate list of equipment is: a crane, a mortar mixer, a concrete mixer, a vibrator, an electric rammer, a welding unit, a mobile power plant.

It is possible to increase efficiency in the installation of pipes if you organize the processes of manufacturing, delivery of structures and installation of pipes on the site, observing a single comprehensive schedule.

A prerequisite for these events is good entrances and developed building bases. The foundation and the number of pipe heads in this situation are mounted "from wheels". Required Items removed by crane from the vehicle and placed in the structure.

The device of the pile foundation is very common where weak soil is present. Piles are driven mainly by units, which include pile driving equipment based on tractors, truck cranes or excavators.

Culvert reinforced concrete pipes: installation

Prefabricated heads and pipe bodies begin to be mounted after the foundation device and axillary backfill.

Before installation, the foundation and head blocks, links must be cleaned of dirt, and in winter conditions - of ice and snow.

A link or blocks that have a flat surface of the lower faces must be installed on a cement mortar. Cylindrical links are required to be installed on wooden linings in compliance with the required clearances between them and the foundation. Subsequently, it is knocked under the links concrete mix, thereby ensuring full contact of the links over the entire distance.

The solution must be poured from one side, while controlling its appearance from the other. Then the missing solution is replenished from the opposite side. This ensures complete alignment and filling of the seams. Solution is necessary such where mobility makes about 12 centimes.

By filling vertical and horizontal seams, it is possible to ensure continuous and monolithic structure pipes in the area where expansion joints are present.

Docking seams on links or sections of pipes are characterized by caulking on all sides with tow, which is impregnated with a bituminous mixture. On the inner sides, the seams must be sealed by 0.03 m using cement mortar.

The entire installation process is carried out in compliance with the design gaps between the links and blocks in order to maintain the sectional size and prevent overlapping of the expansion joint.

Waterproofing and piping

The main type of insulation is reinforced concrete and today occurs using bituminous mastic.

Coatings are arranged unreinforced (coated) and reinforced (pasted). Coating waterproofing- these are two layers of bituminous mastic, each having a thickness of 1.5-3 mm over the soil layer.

Reinforced waterproofing consists of material layers between a three-layer bituminous mastic over a primer layer.

The surfaces of elements of reinforced concrete pipes and their elements (links, floor slabs, nozzles, and others) are usually protected by glued insulation.

Waterproofing: work sequence

surface preparation;
proper waterproofing;
protective layers.

During surface preparation, when working with a structure, it is necessary to clean it from dirt, dry it, and in some situations it is necessary to level it with a cement mortar.

It is necessary to apply a preparatory layer from a cement mortar where internal corners are formed, for example, on the ceilings of pipes and heads in front of cordon stones, for a drain device in a multipoint pipe, etc.

The first technological operation is waterproofing, that is, it is necessary to apply on the insulated surfaces bituminous varnish, which acts as a primer, in order to fill small cracks and pores. In addition, it improves the adhesion of bituminous mastic and concrete surfaces.

There are also non-mechanized methods of priming devices using brushes.

Non-reinforced waterproofing is arranged after the primer has dried, but not less than 24 hours after application.

Hot mastic is applied in layers with a thickness of 1.5-3 millimeters, moreover, the next layer after the first one has cooled down. For these purposes, hand tools (spatula, etc.) are used. It is possible to improve the quality of work and reduce labor costs if mechanized methods are used, mainly using pneumatic spraying.

Reinforced waterproofing is arranged in this way: first, one layer of hot bitumen is applied and a layer of one of the rolled materials is glued. The same is repeated for subsequent layers. The layer that will be the last must be covered with mastic 1.5-3 mm thick and leveled using a manual electric roller, if necessary, supplement the places where the waterproofing was insufficient.

Individual canvases are overlapped with a 10 centime overlap. The first and second joint should not be one above the other. Subsequent joints are made with a shift of at least 0.3 m relative to the joints of previously laid layers.

The rolled material is pasted without the formation of bubbles, while a snug fit of the material on all surfaces is required. Waterproofing is smoothed out with the help of electric irons, electric rollers.

The device of protective layers is necessary so that the waterproofing is not subjected to mechanical damage during backfilling, given that it is one of the important elements during many years of operation and normal operation of pipes.

Backfill

Reinforced concrete culverts must be covered with soil after all construction work has been completed and the appropriate acceptance certificate has been issued.

For these purposes, the same land from which the embankment was erected is suitable.

Bulk construction over culverts is divided into two stages:

Fill with soil the sinuses between the foundation and the walls of the pit.
Fill pipes at link height.

The soil is laid simultaneously on all sides of the pipe to an equal height and compacted by special soil-compacting vibro-impact machines, and in their absence, pneumatic rollers are used. The soil prism is backfilled with the help of inclined layers, the thickness of which is assigned taking into account the current standards.

When moving along a separate soil layer along the pipes, the machine should start working from a remote area, gradually approaching the pipes themselves. It is possible to compact the soil directly at the pipes themselves, if on the opposite side there is already a backfilled layer of earth of the same level along the entire length of the pipes. In this case, special attention is paid to soil compaction at the pipe walls. Here, a manual electric rammer should be located no closer than 0.05 mA from the wall.

Over the middle parts of the pipes, it is forbidden to re-compact the soil in order to avoid structural overloads in the future. With significant bulk heights of more than 10 m above the pipes, it is recommended to leave a zone where the density is reduced. Next, level the ground with a bulldozer without seals.

If, during construction, the equipment that moves over or near the backfilled structures is heavier than the live loads, then additional backfilling is required to avoid damage to the pipe.

The degree of soil compaction within the prism limits of the backfill is assessed using the coefficient K, which determines the ratio of the density that has been achieved to the standard maximum (determined by the standard compaction method). The latter is given in the production working draft, which includes data from geological and engineering surveys. The current instruction requires that a compaction factor of at least 0.95 be ensured. Density control is carried out by a Kovalev moisture meter-density meter. It should be said that in the processes of backfilling pipes, deviations from K, which is equal to 0.95, to the smallest side are prohibited. After all, with a decrease in the density of the earth, the deformation modulus and the bearing capacity of the pipes are significantly reduced.

Safety (TB)

Only those workers who have passed the necessary medical commission and introductory (general) safety briefing and safety briefing directly at the place of work can be hired for this job.

In addition, employees are required to learn a safe method of work according to a program lasting 6-10 hours within three months from the start of work. After graduating from training, you should pass an exam in a permanent commission, the results of which will draw up an act that needs to be invested in the employee's personal file.

The construction site must have permanent or temporary sanitary facilities: latrines, washrooms, changing rooms, clothes dryers, eating areas, showers, first-aid posts or first-aid kits. Workers must be provided with drinking water.

The construction administration must provide workers with overalls, footwear and personal protective equipment in accordance with current regulations.

Builders need:

carry out the correct and safe conduct of construction and installation works;
control the condition of scaffolding and scaffolding, protection devices, foundation pits, etc.;
check the cleanliness and order at work places, on access roads and aisles,
to ensure the illumination of workplaces, to check the correct operation of underhead and crane roads;
instruct employees on safety at the workplace in the workplace;
control the application and proper use by workers individual funds protection and overalls;
monitor compliance with the norms of carrying gravity, provide workplaces with posters and inscriptions.

General provisions sheet 4

Construction of reinforced concrete pipes sheet 6

Executive work sheet 8

Safety instructions sheet 15

List of used literature sheet 16

Introduction

Culverts are man-made structures designed to pass small permanent or periodic active watercourses under road embankments. In some cases, pipes are used as tunnel-type overpasses, cattle passes, etc.

When designing a road, especially at low heights, often

you have to choose one of two possible structures - a small bridge or a pipe. If the technical and economic indicators of these structures are approximately the same or differ slightly, preference is given to the pipe, since:

the installation of a pipe in an embankment does not violate the continuity of the subgrade and the superstructure of the track;

operating costs for the maintenance of the pipe are much less than those of a small bridge;

when the height of the backfill above the pipe is more than 2 m, the effect of the live load on the structure decreases, and then, as this height increases,

practically loses its value.

General provisions

Culverts are distinguished:

according to the material of the pipe body - concrete, reinforced concrete, metal, polymer;

cross-sectional shape - round, rectangular, ovoid;

by the number of points in the section - one-, two-, multi-point;

according to the work of the cross section - non-pressure (working with an incomplete cross section throughout), pressure (working with a full cross section throughout), semi-pressure (working at the inlet head with a full cross section, and for the rest of the length - incomplete).

Pipe holes for highways should take at least:

1.0 m - with a pipe length of not more than 30 m;

0.75 m with a pipe length of not more than 15 m;

0.50 m at the exits when installed within the fast flow pipe.

On on-farm roads, pipes with holes of 0.5 m in size can be used with their length not exceeding 10 m.

The thickness of the backfill above the links or slabs of pipes to the bottom of the road

clothing is accepted at least 0.50 m.

Small, medium road bridges and culverts are allowed to be located on road sections with any profile and plan adopted for this category of road.

Pipes, as a rule, are arranged in a non-pressure mode and, as an exception, in pressure and semi-pressure modes to pass the estimated water flow.

It is impossible to build pipes in the presence of ice, ice drift. On rivers and streams that have spawning grounds for fish, pipes are arranged with the permission of the inspection of fish supervision.

The elevation of the edge of the subgrade at the approaches to the pipes above the calculated water level should be taken at least 0.50 m, and for pipes operating in pressure or semi-pressure mode - at least 1.0 m.

Pipe heads are arranged from a portal wall and two sloping wings buried in the ground below the freezing depth by 0.25 m and

installed on a crushed stone base 10 cm thick. Natural soil below the freezing depth is replaced by sand and gravel

Notes.

1. Pipes are divided into 3 groups according to their bearing capacity:

the first (1) - with an estimated height of backfilling with soil of 2.0 m;

the second (2) - 4.0 m;

third (3) - 6.0 m.

It is allowed to use pipes for specific conditions of pipeline construction at a different design height of backfilling with soil.

2. The pipe brand consists of alphanumeric groups separated by a hyphen. The first group contains the pipe type designation,

the second is the diameter conditional pass in cm and useful length in dm, group number according to bearing capacity.

3. Pipes should be made in accordance with GOST 26633 from heavy concrete compressive strength class B 25.

4. The water resistance of the concrete pipes must comply with W 4.

5. Pipes TB, TBP, TS and TSP are supplied to the consumer complete with rubber sealing rings.

6. Cracks on the surface of pipes are not allowed, except for shrinkage cracks with a width of not more than 0.050 mm.

Pipe heads with a hole of 0.50 ... 0.75 m are constructed from a portal wall buried in the ground below the freezing depth by 0.25 m.

Sloping wings are allowed to be made of monolithic concrete

grade B 15 without reinforcement with formwork dimensions of precast concrete blocks.

Pipe length (Ltr) is determined by the formula

Ltr \u003d B + 2 (H-d-c) * m,

where B is the width of the subgrade, m;

H is the height of the embankment, m;

d – pipe opening, m;

с – wall thickness, m;

m is the slope factor.

Construction of reinforced concrete pipes

Preparatory work on the basis of the enterprise (recommendations).

1. Checking pipe elements for permissible deviations in accordance with GOST

(link length - 0 ... 10 mm, wall thickness -5 ... + 10 mm, other changes

rhenium - +10 mm).

2. Removal of sagging, splashing of concrete on the articulating parts of the links.

3. Selection of all pipe elements by grades according to the design solution.

4. Storage of pipe elements in one place.

Preparatory work at the construction site

1. Selection and preparation of the construction site. Shrub uprooting

and site leveling by bulldozer.

2. Reception and placement of equipment, material and structures.

3. Breakdown of the axis of the pipe and the contour of the pit.

Geodetic work performed during the construction process consists of: laying out the structure in the plan, including the main axes and contours of the pit; altitude breakdown; leveling the longitudinal profile of the pipe tray.

The breakdown in the plan is fixed in place clearly visible marks, by which you can accurately determine the location of the pipe and its elements; they are usually fixed with the help of two pillars installed along the longitudinal axis of the pipe, taking into account their safety for the entire time of construction, and stakes driven along the axis of the embankment and at characteristic points. AT

in some cases, at a distance of 1.5-2 m from the boundaries of the pit, cast-offs are made of horizontally installed boards, on which the characteristic points of the foundation are marked. Boards are nailed to posts buried in the ground. When laying out a structure in the plan, it is necessary to strictly maintain the position of the target located along the axis of the embankment, and to be creative in laying out the longitudinal axis of the pipe. If any unfavorable soil or other factors are identified at the location of the pipe, it must be shifted to one side or the other. All deviations from the project are agreed with the customer and the design organization.

Altitude breakdown consists in determining the surface marks at the location of the pipe and the depth of cutting the soil or, conversely, its backfilling under the pipe. Earthworks for digging pits and laying foundations are carried out under instrumental control.

With the help of a level, they check the compliance of the actual marks of the bottom of the pit and the top of the pillow with the design ones. Similarly, the height position of the foundation is controlled, and then the pipes. The longitudinal profile of the pipes is leveled before their backfilling and after filling the embankment to the design marks. The need, as well as the frequency and duration of further observations are established, guided by the standards.

Altitude staking and leveling is carried out with reference to a benchmark located near the pipe.

Pipe layout diagram: Fig. one

Executive work

1. Digging a pit with an excavator and cleaning it manually. Strengthening (if necessary) the bottom of the pit stone materials by pressing with means of drowning.

Excavations for the foundations of culverts are developed in most cases without fastening (fencing). Only in water-saturated soils with a significant influx of water and the inability to ensure the stability of the walls of the pit, the soil is developed under the protection of the fastening. Pit fastenings are also used during the construction of pipes in the immediate vicinity of the operated structures, thereby ensuring their stability.

The outline of the pits and the technology for their development depend on the design of the pipe and its foundation, on the type and condition of the foundation soils.

The steepness of the slopes of the pits is assigned taking into account the depth of the pit and the characteristics of the developed soil.

The distance between the vertical wall of the pit and the side surface of the foundation is used at least 0.7 m, if it is planned to apply waterproofing to the structure or perform other work related to the stay of people in the pit. When such work is not provided, this value can be reduced to 0.1 m. In case of formless concreting of foundations, the dimensions of the pit are assumed to be equal to the dimensions of the foundation. When developing pits with slopes, the distance between the bottom of the slope and the foundation should be at least 0.3 m. In all cases, the dimensions of the pit are linked to the capabilities of earthmoving equipment.

In all cases, when digging pits, measures are taken to prevent their filling with surface or ground water. For

this, soil rollers are poured along the contour of the pit. When constructing a pipe on a permanent watercourse, they build dams or divert the channel to the side with the help of ditches.

The water that has penetrated into the pit is removed, either by arranging an outlet into the drainage ditch in its lower part, which is usually possible when building slope pipes, or by providing mechanized drainage. For drainage, a fenced pit is made in the lower part of the pit, from which water is pumped out with a pump. The pit is located outside the contour of the foundation, ensuring the removal of water during foundation work up to the backfilling of the sinuses. As the pit deepens, the pit fences are lowered. Non-rocky soils are developed by earthmoving machines without disturbing the natural composition of the soil at the base with a shortage of 0.1-0.2 m. The pit is finally cleaned immediately before the foundation is laid.

Currently, of the diverse earth-moving equipment in the construction of culverts on railways and roads, bulldozers and excavators are most widely used.

The development of pits by a bulldozer is most appropriate when laying the foundation of the pipe body and head at the same mark or with a small difference between them.

For unenclosed pits, excavators equipped with a backhoe or draglines are used. The advantage of these mechanisms is the possibility of excavating the soil at different depths of the excavation, which ensures the excavation under the middle part of the pipe and heads, the base of the foundation of which is laid at a greater depth. For the development of protected pits, it is advisable to use grabs.

In all cases, the developed soil is laid outside the pit at a distance that ensures the stability of its walls or fence. Soil dumps should not create difficulties for subsequent construction and installation work, as well as for water passage.

2. Foundation device.

There are small-clastic and large-block foundations.

When installing foundations from prefabricated elements, first of all, blocks of head foundations are laid up to the level of the sole of the foundation of the pipe body. Then, the sinuses of the foundations of the caps are filled to the same level. From three sides they are covered with local soil, at the junction of foundations different depth laying - sand-gravel or sand-gravel mixture, which is compacted in layers and poured with cement mortar. Then the laying of the foundations of the heads is carried out simultaneously with the sectional installation of the foundation of the pipe body. The order of installation is taken sequentially - from the output head to the input. Multi-row masonry is performed with dressing of seams.

The technological process for the installation of monolithic foundations includes the manufacture and installation of formwork, the delivery of ready-mixed concrete or its preparation on site, the laying of the mixture, concrete maintenance, formwork removal, backfilling of sinuses. Fairly simple outlines of the foundations make it possible to produce formwork in the form of inventory boards used at a number of objects. The surface of the shields must be smooth. Before concreting, it is recommended to coat it with grease, which will facilitate the separation of the shields from the concrete structure.

To load the concrete mixture into the formwork of the sections, inventory trays or tubs are used, loaded on site or delivered from concrete mixing units. The contents of the tub are unloaded directly into the sections. Compact concrete with deep or surface vibrators.

Prefabricated monolithic foundations are built in the following sequence: formwork is installed on the prepared base or pillow in the seams between the sections; the space between the prefabricated elements and the formwork in the joints is filled with a concrete mixture. The requirements for the production of concrete work in this case are the same as for the installation of monolithic foundations.

Equipment and mechanisms for the construction of the foundation are selected taking into account the entire technological process for the construction of the pipe. An approximate list of the main equipment includes: cranes, mortar mixers, concrete mixers, vibrators, electric rammers, welding units, mobile power plants.

Improving the efficiency of the pipe device can be achieved by a clear organization of the process of manufacturing, delivery of structures and

installation of pipes in a certain area according to a single integrated schedule.

A necessary condition for this is the presence of good entrances and a developed construction base. The foundations, as well as the body of the pipe and the heads, in this case, are mounted “from the wheels”, removing the elements from the cranes Vehicle and putting them into a structure.

The device of pile foundations is common in areas with weak soils. Piles are loaded mainly with pile-collecting units, including pile-driving equipment based on a tractor, truck crane or excavator and a diesel hammer.

3. Installation of prefabricated reinforced concrete pipes.

The installation of prefabricated heads and the body of the pipe is started after the installation of foundations and backfilling of the sinuses.

Prefabricated pipes are mounted using self-propelled cranes, the lifting capacity of which is determined based on the mass of the blocks of the pipe body, heads and foundation, taking into account the possible outreach of the crane boom.

The order of installation is determined depending on the design of the head part of the pipe and local conditions.

Before starting the installation, the links, head blocks and foundations are cleaned of dirt, and in winter from snow and ice.

Links and blocks with a flat surface of the lower face are installed on a cement mortar with a mobility of 6-8 cm along the cone of StroyTsNIIL. Cylindrical links on a flat surface of the foundation are installed on wooden linings, observing the required gap between the link and the foundation. Then, a concrete mixture is knocked under the link, ensuring full contact of the link along its entire length. The solution is poured on one side, controlling its appearance on the other. Then the missing amount of mortar is replenished from the opposite side of the link, while ensuring complete filling and alignment of the seam. The solution is used with a mobility of 11-13 cm.

The filling of vertical and horizontal joints ensures the continuity and solidity of the pipe structure in the areas between expansion joints.

Seams in the joints of links or sections of pipes are allowed to be caulked on both sides with bitumen-impregnated tow. With inside seams should be sealed to a depth of 3 cm with cement mortar.

During installation, compliance with the design clearances between blocks and links within each section is monitored in order to maintain the dimensions of the sections and prevent expansion joints from overlapping.

4. Pipe waterproofing device.

The main type of insulation for concrete and reinforced concrete pipes is currently bituminous mastic.

Coatings are arranged unreinforced (coated) and reinforced (pasted). For pipes, non-reinforced waterproofing consists of two layers of bituminous mastic 1.5-3 mm thick each over a primer layer, reinforced - from layers of reinforcing material between three layers of bituminous mastic also over a primer layer.

The surfaces of reinforced concrete pipe elements - links, floor slabs, nozzles and others in contact with the ground, as a rule, are protected with reinforced waterproofing.

The sequence of work on the installation of waterproofing on a bitumen basis is as follows: surface preparation; device (application or sticker) of waterproofing; protective layer device.

When preparing the surface of the structure, it is cleaned of dirt, dried, and, if necessary, leveled with cement mortar. The application of a preparatory layer of cement mortar is required in places where internal corners are formed, for example, on a pipe overlap in front of a cordon stone, for drains in multipoint pipes, and in other cases.

The first technological operation of the actual waterproofing device is the application of bituminous varnish to the insulated surface. Varnish is applied as a primer to fill small cracks and pores,

as well as to improve the adhesion of the main component of waterproofing - bituminous mastic - with a concrete surface. It is recommended to apply bituminous varnish by spraying, using installations consisting of a container and a spray pneumatic nozzle. There is also a non-mechanized method of priming with brushes.

Non-reinforced waterproofing is arranged after the primer dries, but not earlier than 24 hours after its application. Hot mastic is applied in layers 1.5-3 mm thick, the second layer after the first one has cooled down. Used to apply mastic hand tool- spatulas, etc. Improving the quality of work and reducing labor costs are achieved using a mechanized method, mainly pneumatic atomization.

Reinforced waterproofing is arranged in this sequence. First, the first layer of hot bituminous mastic is applied to the primed surface and the first layer of reinforcing roll material is glued; repeat these operations for the next layer. Then

the last layer of the reinforcing material is covered with a finishing layer of mastic 1.5-3 mm thick, leveling it after cooling with a manual electric roller and adding mastic to the places where it was not enough. Separate panels of reinforcing material are overlapped with overlapping joints by 10 cm. The joints of the first and second layers should not be located one above the other. The joints of each next layer are shifted by at least 30 cm relative to the joints of the previously laid layer. Roll materials stick, avoiding the formation of bubbles and achieving a snug fit of the material over the entire surface. Electric irons, electric rollers are used to smooth the insulation.

The protective layer is arranged to prevent mechanical damage to the waterproofing during the backfilling of the pipe and in the subsequent period, taking into account the fact that the safety of the waterproofing during many years of operation is one of the most important factors in the normal operation of the pipe.

5. Soil backfill.

Reinforced concrete culverts are covered with soil after all work on their construction has been completed and an appropriate acceptance certificate has been issued.

The same soil from which the embankment was erected is suitable for backfilling pipes.

The erection of embankments over reinforced concrete pipes consists of two stages:

filling the sinuses between the walls of the pit and the foundation with soil;

backfilling of the pipe to the height of the link.

The soil is laid simultaneously on both sides of the pipe to the same height and compacted in layers by a special vibro-impact soil-compacting machine for working in cramped conditions, and in its absence, by pneumatic rollers. The soil prism is poured in layers inclined from the pipe (with a slope not steeper than 1: 5), the thickness of which is determined in accordance with applicable standards.

The movement of soil-compacting machines along each layer of soil along the pipe should be started from sections remote from it and approach the pipe walls with each subsequent pass. Soil compaction directly at the pipe is allowed if a layer of soil has already been poured on the opposite side at the same level along the entire length of the pipe. Particular attention should be paid to soil compaction at the pipe walls. In this case, a manual electric tamper must be located at a distance of at least 5 cm from the wall. Above the middle part of the pipe (above the links), over-compaction of the soil is not allowed in order to avoid overloading the structure.

With a significant height of the embankment (more than 10 m) above the pipe, it is advisable to leave a zone of reduced (less than 0.95 of the maximum) density, leveling the soil of this zone with a bulldozer without compaction.

If, during the construction process, vehicles moving over or close to the backfilled structure are heavier than the live loads for which the pipe was designed, additional backfilling must be provided to avoid pipe failure.

The degree of soil compaction within the backfill prism is estimated by the coefficient K, which determines the ratio of the achieved density to the maximum standard, determined by the standard compaction method. The latter is given in the project for the production of works based on the data of engineering and geological surveys. In accordance with the requirements of the current instructions, the compaction coefficient is provided not lower than 0.95.

Online density control in field conditions lead by N. P. Kovalyov's density meter-moisture meter.

It should be noted that in the process of backfilling the pipe, deviations from K = 0.95 downwards should not be allowed, since a decrease in soil density significantly reduces its modulus of deformation, and, consequently, bearing capacity pipes.

Safety

All newly arriving workers are allowed to work on the conclusion of the medical commission and only after passing the introductory (general) safety briefing and safety briefing directly at the workplace.

In addition, workers must undergo training within a three-month period from the date of receipt. safe methods work on a 6-10 hour program.

Upon completion of training, it is necessary to conduct examinations in permanent commissions and draw up an act that must be kept in the worker's personal file.

The construction site should be equipped with permanent or temporary sanitary facilities: latrines, washrooms, changing rooms, clothes dryers, eating areas, showers, first-aid posts or a first-aid kit. Workers must be provided with drinking water.

The construction administration is obliged to supply workers with overalls, footwear and personal protective equipment in accordance with the nature of the work in accordance with applicable standards.

The following tasks are assigned to construction foremen within the areas of work assigned to them:

implementation of the correct and safe conduct of construction and installation works using construction machines, mechanisms, mechanized tools and equipment;

monitoring the condition of scaffolding and scaffolding, protective devices, fixing pits, trenches, etc.;

checking the cleanliness and order at workplaces, in the aisles and access roads, ensuring the illumination of workplaces, checking correct operation undercrane and underhead tracks;

instructing workers on safety at workplaces in the process of work;

application control and correct use working clothes and individual protective equipment, for compliance with the norms of carrying heavy loads, for providing workplaces with warning signs and posters.

Bibliography

Road construction (a manual for foremen and foremen of road organizations) VG Popov.

Culverts under O. A. Yankovsky's embankments.

Bridges and structures on highways M.E. Gibshman,

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1. MT construction methods. Expand one of the methods

The basis for the construction of the main pipeline should be the availability of the following documents:

an approved project (working draft) and a summary estimate of the cost of construction or extracts from them, when construction is carried out by several general contractors;

working drawings and approved estimates for working drawings (object and local);

permissions of the relevant departments and operational services for the right to perform construction and installation works;

approved project for the production of works;

2. Composition of general construction works for the construction of the PS and CS.

centering

earthen

Building construction installation

2. Hydraulic and pneumatic test method

The hydraulic test is carried out mainly with water. Natural or artificial reservoirs (rivers, lakes, reservoirs, canals, etc.) are used as its sources. The pipeline is filled with water using filling units through the connection points. Since the presence of air in the cavity of the pipeline can distort the test results, air bleed valves cut into the elevated points of the profile to remove it.

When testing for strength in the pipeline, it is necessary to create a pressure that is 10 ... 25% higher than that with which the pumping will be carried out. First, the pressure in the test area is increased by filling units. When will they technical capabilities are exhausted, the filling units are turned off and the pressure testing units are turned on. After reaching the design pressure, they are turned off, the valves are closed and the pipeline is kept under test pressure for 24 hours.

If ruptures occur during pressure rise or holding, the pipes of the damaged section are replaced with new ones, and the test is repeated.

The leak test measures the reduction in operating pressure over a specified period of time. If it is insignificant, then a conclusion is made about the tightness of the tested section of the pipeline. pipeline trunk construction underground

Hydraulic tests are completed by displacement of water from the cavity of the pipeline. For this, at least two separator pistons are passed at the speed of 3 ... 10 km / h under the pressure of compressed air or gas on main gas pipelines. Water from oil and oil product pipelines after their testing is removed by one piston-separator, moved under the pressure of the transported product.

Pneumatic testing of pipelines is carried out with compressed air or natural gas. Their sources and means of injection are the same as for blowing. The pressure increase in the pipeline is carried out in several stages with a mandatory inspection of the route when a pressure equal to 30% of the test pressure is reached. Then the pressure is raised to the test pressure (1.1 Rrab) and, having closed the shut-off valves, the pipeline is kept for 12 hours. The permissible pressure drop is no more than 1%. Then the pressure is reduced to the operating pressure and maintained for at least 12 hours more. In the event of air leaks or pipe rupture, the air supply is immediately stopped, the pressure is reduced to atmospheric pressure and work is carried out to eliminate defects, after which the test is resumed. At the end of the test, the equipment is dismantled and relocated to a new site.

The advantage of the pneumatic test method is the refusal to use significant amounts of water. In addition, there is no need to displace it at the end of the test. Therefore, it is widely used in testing the strength and tightness of gas pipelines. However, the detection of leaks in pipelines using this method is associated with certain difficulties. So, when compressed, the air heats up. With its subsequent cooling, the pressure in the pipeline decreases, which can be erroneously identified as a leak. On the other hand, air is a compressible medium. Therefore, even in the presence of a small leak, the rate of pressure reduction in the pipeline is small.

The hydraulic method allows fixing even minor leaks: water is a practically incompressible medium and its relatively small leakage leads to a noticeable decrease in pressure in the pipeline. To reduce the amount of water used, it is sequentially moved from one test area to another. However, if the test water cannot be completely displaced, this leads to internal corrosion of the pipelines. In addition, not always along the route there are sufficient volumes of water for testing.

In order to reliably establish the absence of leaks in pipelines in conditions of limited water resources, a combined test method is used, when the pressure in the pipeline is created by two media - air and water or natural gas and water. In this case, the pipeline cavity is first filled with compressed air or gas, and then the pressure is raised to the test pressure by pumping water with pressure testing units.

3. Construction of block-complete NS and KS. The essence of this method. The main elements in the complete-block construction

To ensure high rates of construction of the PS and CS under these conditions, a complete-block construction method is used. The essence of this method lies in the fact that objects are erected from products of a high degree of prefabrication in the form of block-assembly devices (BKU), enlarged assembly units and engineering communications blanks.

In the case of complete-block construction, the following elements are distinguished: block, box, block-box, superblock and block-complete device.

A block is a collection of equipment and building structures mounted on a common base (block gas turbine plant, block pump unit, transformer block, etc.). The block must fit into the loading dimensions (Fig. 20.9) - the maximum dimensions of goods transported by rail on a platform or in a gondola car.

Boxing is a transportable building made of lightweight building structures that fits into the loading dimensions.

A block box is a box stuffed with technological equipment and engineering systems, inside which they create a microclimate necessary for long-term work of maintenance personnel and reliable operation installed equipment.

The block container differs from the block box in that the access of personnel to the installed equipment is carried out from the outside.

A superblock is a block (or a set of blocks) whose dimensions exceed the loading dimensions.

A block-complete device is an object assembled at a specialized enterprise or an installation site from a set of blocks, boxes, block containers, block boxes, superblocks and interblock communications blanks.

The scheme of organization of prefabricated construction of NS and CS is shown in fig. 20.10

Prior to the installation of block devices, foundations are built for them. In the absence of technological equipment in the block-boxes (operator's rooms, rest rooms, etc.), special foundations are not erected, and the box's support frame is installed on a compacted layer of sand and gravel mixture 10 ... 15 cm thick. In other cases, the choice of the type of foundation depends on the nature of the operation of technological equipment, the presence or absence of dynamic loads.

4. Trenchless method of constructing underground crossings of pipelines

The trenchless method is called because when laying both the casing and the pipeline, they do not arrange an open trench. The technological scheme for performing trenchless laying of crossings includes the following main operations:

Preparatory work;

Laying a casing under the roadbed;

Laying the pipeline inside the casing;

The device of seals, an exhaust candle or a well, a diversion ditch.

The main volume of preparatory earthworks constitutes the arrangement of the working and receiving pits. The pits are torn off to a depth somewhat lower than that at which the casing should be laid. The working pit has dimensions that allow you to install everything in it necessary machines and mechanisms and perform work related to laying the casing. The dimensions of the receiving pit must be such that it is possible to carry out the necessary installation work in it to connect additional transition pipes or to make a sealing connection between the casing and the pipe.

The laying of the casing under the road can be performed by various methods: piercing, punching, horizontal drilling and vibro-impact method. In exceptional cases, the methods used in mine construction, associated with the use of special mining equipment and technology, may be used.

After laying the casing, a pre-prepared working pipeline is dragged into it. After pulling through, oil seals, exhaust candles are installed, receiving wells are equipped, diverting ditches, and the initial state of roadside structures is completely restored, as well as the landscape of the area. Particular attention should be paid to the latter, since the unrestored relief begins to intensively deform under the influence of rain, wind, and other climatic factors.

5. Accounting for oil. Requirements for oil metering stations

The operating principle of the UUN is based on the direct method of dynamic measurements of the "gross" mass of oil using automatic in-line mass flow converters (hereinafter referred to as mass meters), operating on the principle of measuring the Coriolis force that occurs when oil moves along a pipeline section with a given radius of curvature, in which transverse vibrations. The mass of oil is determined on the basis of the known dependence of the Cariolis force on the oil flow rate and the frequency of transverse vibrations of the measuring section of the pipeline. The "net" weight of oil is defined as the difference between the "gross" weight of oil and the weight of ballast. The ballast mass is determined from the results of measurements of the mass fraction of water, the mass concentration of salts and the mass fraction of mechanical impurities in oil, obtained, including in the laboratory, from a combined sample taken automatically or manually.

Structurally, the UUN consists of the following parts:

Measuring line unit (MIL), consisting of five mass meters, pressure and temperature measuring transducers built into the pipeline, designed to measure the mass flow rate of oil, its temperature and pressure and transmit data to the IMTs-03 measuring and computing complex;

oil quality control unit (OQU), consisting of a sampling device that continuously takes point samples of oil from the pipeline for subsequent laboratory analyzes of oil quality parameters and subsequent manual input of the obtained data into the IMTs-03 IMC, measuring transducers for density, temperature and pressure;

6. Laying the casing under the road by punching

The piercing method is as follows. The frontal part of the casing is equipped with a special pointed tip, the diameter of which is 30-40 mm larger than the outer diameter of the casing. With the help of special jacks installed in the working pit and resting against the back wall of the pit, the tip is pressed into the ground. As the casing is introduced into the ground, it is built up with additional pre-prepared sections. With this method of laying the casing, a very large punching force is required, since when it is introduced into the soil, the soil is compacted with a tip, i.e., it is necessary to overcome the frontal resistance of the soil and the friction force of the outer surface of the casing against the soil.

When laying by piercing, it should be borne in mind that the minimum depth of the pipe should be 3 m, since at a shallower depth the soil surface above the pipe swells, which is completely unacceptable when crossing railways.

The punching method avoids this drawback. The essence of punching is that the casing is pressed into the ground with its open end, and the soil entering the casing is removed.

7. Specify the main elements and nodes of the CS

The main oil pipeline, in general, consists of the following complexes of structures:

supply pipelines;

Head and intermediate oil pumping stations (PS);

Final destination;

Linear buildings.

The supply pipelines connect the oil sources with the main facilities of the OOP.

The main PS is designed to receive oil from the fields, mix or separate them by grade, account for oil and pump it from tanks into the pipeline.

Intermediate PSs serve to replenish the energy expended by the flow to overcome friction forces in order to ensure further oil pumping.

The end point of the main oil pipeline is usually an oil refinery or a large transshipment tank farm.

The linear structures of the main oil pipeline include: 1) the pipeline itself (or the linear part); 2) linear valves; 3) means of protecting the pipeline from corrosion (cathodic and sacrificial protection stations, drainage installations); 4) crossings over natural and artificial obstacles (rivers, roads, etc.); 5) communication lines; 6) power lines; 7) linemen's houses; 8) helipads; 9) dirt roads along the pipeline route.

8. Production methods overhaul gas and oil pipelines

* all types of work used in current repairs;

* replacement of insulation of gas pipelines, restoration of the pipe wall with the replacement of insulation, patching, cutting and inserting a new coil, replacement of individual sections of pipes.

* repair of masonry wells with disassembly and replacement of floors, repair of waterproofing and plastering of wells, change of stairs and running brackets, increasing the height of wells;

* removal of individual sections of gas pipelines on the facades of buildings;

* disassembly of valves and replacement of worn parts, scraping, boring or replacement of sealing rings, lubrication;

* replacement of worn valves;

* dismantling or replacement of condensate collectors and water seals, repair and replacement of carpets;

* replacement of supports of above-ground gas pipelines;

* laying of separate sections of gas pipelines

9. Work performed during preparatory phase NS and CS facilities

1. Arrangement of the construction site, access roads

2. Construction of temporary premises for living and consumer services workers, as well as to accommodate arriving equipment and materials

3. Delivery to the construction site fuel

10. Classification and methods for reducing oil losses during pipeline transport

Technological losses of oil (petroleum products) during pipeline transportation and transshipment may occur when:

Collection and disposal of leaks through stuffing box and end seals of shafts of centrifugal pumps;

Injection and pumping out from tanks of pumping stations, transshipment tank farms and filling points of main pipelines

Accidents, leaks, dug TP

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PVC

In Western countries, pipes made of polyvinyl chloride appeared in the mid-thirties of the twentieth century. They have been used for a long time for arranging a cold water supply network in individual construction. At the moment, this type of construction is practically not used in European countries (over time, PVC begins to release toxins during operation), the only exception being sewage systems.

In our country, PVC pipes are used as underground water and sewer networks outside buildings. AT high-rise building PVC pipes are not used as they are not suitable due to the organic diameter. In addition to all this, PVC structures are short-lived, and the most vulnerable places are at the joints (the installation of this type of pipe is done using glue fittings).

As for PVC pipe segments, they are among the most low-capacity ones. These products are supplied to the market mainly by Polish manufacturers, such as Crap-linnski, Kaczmarek, Armakan, including the Brovarsky Plastics Plant and others.

Polyethylene

One of the main advantages of polyethylene pipes is their resistance to low temperatures(up to -20 degrees Celsius), this in turn allows you to lay network engineering in winter period and exploit them in pretty tough climatic conditions. As a rule, polyethylene pipes are used mainly for cold water supply, since when exposed to high temperatures, strength this material decreases, and it softens to some extent. It is not recommended to use polyethylene pipes in open networks, because under the influence of direct sunlight they quickly age. To stabilize the material, the developers began to add carbon black to the polymer.

There are also pipes made of cross-linked polyethylene. Such a material is much stronger than conventional, and in addition, it is even more resistant to high temperatures. Pipes of this type are widely used for hot water supply, as well as in heating systems (pipes equipped with an “oxygen-blocking layer”). The material that is used for the manufacture of polyethylene crosslinked pipes is crosslinked by several methods: peroxides, ionizing radiation, organosilicon substances. Polyethylene pipes are connected mechanically by means of propylene and brass fittings.

metal-plastic

Metal-polymer pipes are a fairly reliable building product, which consists of five layers, namely: the main pipe is made of cross-linked polyethylene, an adhesive layer applied to outer surface, layer aluminum foil, the thickness of which is 0.1-0.15 millimeters, another adhesive layer, an outer protective sheath made of polyethylene. Metal-polymer pipes are made by extrusion: that is, the aluminum tape is butt-welded by means of ultrasound and coated on both sides with glue and layers of polyethylene.

Pipes of this type have a low coefficient of linear expansion and are well protected from oxidation. Metal-polymer pipes can be bent in the right direction without fear of rupture. Such pipes tend to retain the shape given to them, this is one of the reasons that they are used in the installation of complex system and piping configurations.

Most effective use pipes of this type in an open supply, for example, they are used to connect water heaters, radiators, etc. But due to the fact that their diameter is not large - up to 40 millimeters, their scope is narrowed.

Polypropylene

Among plastic pipes propylene pipes have the greatest strength and durability at high temperatures. Unlike polyethylene pipes, propylene pipes are more rigid, and their structures are assembled using fittings: tees, angles, etc.

The installation of a polypropylene pipeline takes place under the influence of a temperature of +260 degrees Celsius - this, in turn, provides a fairly strong homogeneous (welded) connection, the most reliable of all methods that exist. The welding process itself is quite simple: cut, heat, join.

metal pipes

There are several types of metal pipes depending on their area of application, namely:
Electrowelded galvanized and black pipes are used as the main elements of plumbing, heating and gas systems, including in the manufacture of metal structures.

Galvanized pipes are endowed with additional corrosion protection. Seamless pipes are widely used in drilling, installation of oil and gas pipelines, heating networks, in machine-building production. Water and gas pipelines (black and galvanized) are used in heating systems, water supply and gas supply.

Galvanized pipes are not subject to rust formation inside the system; profile pipes of this type are used in the production of metal structures, they have both a rectangular section and a square one.

Classification of metal pipes by production method:

welded steel pipes - are made by bending a sheet of steel and making a weld: longitudinal or spiral;
cast steel pipes - pipes of this type are produced at specialized turbo-casting plants;
seamless pipes - are made by means of a solid billet by forging or pressing.

Classification of pipes according to the conditions of use

Depending on the purpose for which pipes are used, they are divided into - pipes for special (purpose) purposes and pipes for general purposes. Pipes special purpose further classified according to the following criteria:

steel pipes, designed for use in heating networks, in gas and water pipelines;
high-strength pipes for drilling rigs - casing and drilling;
pipelines for transportation of oil and gas under high pressure;
boiler pipes, endowed with the property of increased heat resistance;
pipes intended for use in chemical industries have high corrosion resistance;
steel pipes with a rectangular profile - are widely used in mechanical engineering and construction (manufacturing of various types of equipment and attachments for machines);
bearing tubes - mainly used in the production of roller and ball bearings.

Classification of metal pipes according to the method of protection against corrosion
The corrosive process is the main enemy during the operation of metal pipes. The corrosion process can occur both on the outside of the thai and on the inside of the pipes. Protecting pipes from the corrosion process can increase the cost of their production. For example, steel pipes made of stainless steel are mainly used in the chemical and food industries.

As a corrosion control method, the galvanizing method is used, that is, the pipes that are subjected to this process have on their surface thin layer resistant to oxidation and chemical reactions metal. Using this method, the cost of such pipes will be, to some extent, more than pipes made of stainless steel.

Steel pipes coated with a polyethylene anti-corrosion layer will last several decades longer than pipes without any protection.

When purchasing steel pipes, it is necessary to pay special attention to the manufacturer. Pipes manufactured by the domestic industry are of high quality, which is recognized throughout the world. But throughout recent years appeared on the market metal pipes from China, which are sold at dumping prices. Deciding to purchase this product, you should weigh the pros and cons well. Since saving on such materials can result in big losses.

In this case, you can also classify pipes by manufacturer, that is:

metal pipes of a domestic manufacturer - high quality and high price;
Chinese-made metal pipes - mediocre quality and dumping prices.

The construction of any capital building preceded by the construction of the foundation on which it will be equipped. Among the variety of foundations, a pipe foundation is quite popular. Since it is this foundation that is perfect for the construction of small buildings in the form one-story houses, garages or outbuildings. We will talk about the features of building a foundation from pipes further.

Pipe foundation: features, advantages and disadvantages

The main feature of the foundation of their pipes is the process of its construction. In appearance, this foundation resembles a certain number of pillars located from each other at intervals of 150-300 cm. The pillars are located on the corner sections of the building and at the intersection of the bearing walls.

Among the main advantages of a pipe foundation, it should be noted short terms its erection and rather low cost. In addition, a columnar foundation requires very little concrete mortar and reinforcing bars. If we compare the foundation of pipes with belt type, then for the construction of the first one it is not necessary to dig a pit and spend time and money on this, it is enough just to drill small wells.

Subject to all the technologies for arranging the foundation of pipes, it will acquire a fairly decent strength and will serve for a long time.

Please note that the arrangement of such a foundation does not imply the presence of a basement in the house. In addition, it is better to build a foundation of pipes on slopes or on soft soils.

For the manufacture of support pillars various kinds of building materials are used, such as concrete, metal, asbestos cement, brick, wood. The most durable are foundations based on concrete or asbestos cement.

Among their advantages, we highlight:

the highest level of strength;
resistance to spreading;
speed of work.

The pipe foundation has gained popularity due to its ease of construction, less physical effort and affordable cost. Pipes are used as the main material for its construction. In addition, the construction of such a foundation does not require the presence of expensive equipment, it is enough to use a conventional drill, a concrete mixer and improvised tools.

Among the advantages of the foundation of pipes, we highlight:

reduction in the total cost of building a foundation and physical effort to carry out this process, if we compare the costs of arranging a monolithic foundation, they will be twice as high;
the almost complete absence of land work in the form of digging a pit and leveling the soil;
speed of foundation construction and no need to wait for concrete to harden, etc.;
flood prevention, since the main building is 25-30 cm above the ground;
ease of carrying out communication systems.

Despite this, the construction of a foundation made of pipes has the following disadvantages:

the presence of a small bearing load, so the arrangement of such a foundation becomes possible only during the construction of small one-story buildings;
low duration of operation, which does not exceed 85 years;
inability to build basement, which is located at the bottom of the building;
such a foundation is not suitable for areas with too high elevation differences or moving soils.

Column foundation made of pipes: types and their characteristics

In relation to the type of pipes that are used in the construction of a columnar foundation, it happens:

from asbestos-cement pipes;
from concrete pipes;
plastic pipes;
from metal pipes;
from wood.

The foundation of asbestos pipes is different the highest strength, among their advantages are:

the arrangement of the foundation does not require additional costs for the construction of formwork for pouring concrete, unlike concrete pipes;
in addition, a sand and gravel cushion, pit or trench is not arranged under them;
pipe installation does not require machinery or special equipment;
the affordable cost of asbestos pipes allows you to reduce the cost of arranging the foundation.

Disadvantages of the foundation of asbestos-cement pipes:

inadmissibility of use in buildings that are characterized by an increased degree of load;
insecurity for humans;
low service life, about 65 years.

Among the advantages of the foundation of concrete piles are:

resistance to chemicals;
such piles are resistant to corrosion;
absence of defects, since high-grade and good quality concrete is used in the manufacture;
no need for earthworks.

Building a foundation from plastic pipes has the following advantages:

high level of reliability;
resistance to corrosion;
harmlessness to humans, unlike pipes made of asbestos.

Such pipes are used as a foundation exclusively for light buildings, in the form of outbuildings. For the construction of the foundation, sewer pipes are used under the foundation.

The construction of a foundation from metal pipes is distinguished by the following advantages:

high level of strength;
resistance to cracking;
installation speed.

Among the disadvantages of using metal for the construction of the foundation, it should be noted, first of all, its instability before corrosion and the gradual destruction due to this process.

Wooden poles installed for arranging the foundation are also able to withstand a decent load, but they are unstable against the moisture that is in the ground. Over time, these supports begin to rot and collapse.

How to make a foundation from pipes: the initial stage

Before starting work, determine the depth at which the soil lies, for this, the following factors should be taken into account:

soil freezing depth;
availability and depth of groundwater;
soil characteristics on the site;
the total mass of the building.

First, the site is marked, the depth of drilling and the number of pillars are calculated exactly. Further, using a gasoline or hand drill, wells should be made for the installation of pipes.

The interval between the pipes is about two meters. Please note that supports must be present at the corners and intersections of the walls. The drilling depth should be 300 mm more than the depth of soil freezing. This value is approximately 1.5-1.8 m. The size of the hole depends on the diameter of the pipe that will be installed in it. The supporting parts should rise above the surface by half a meter.

Further actions are determined by the type of pipes that were chosen for the arrangement of the foundation.

Asbestos pipes as a base for the foundation

Asbestos pipes have gained popularity due to their affordable cost, resistance to corrosion and exposure to high temperatures. However, this type of pipe needs to be reinforced with reinforcing bars.

The diameter of the asbestos pipe should be about 200 mm, and the height should be 2 m. All pipes are installed in wells, and further actions have two options:

pouring with concrete mortar;
installation of metal rods.

The first option involves the installation of fittings in the pipe, the distance between which is 60-70 mm. The length of the reinforcement should be about 2.5 m. Since it should be 20 cm in the ground and 20 cm protrude from the outside.

Since it is from the reinforcing bars that the grillage is formed. Next, the pillars are poured with concrete mortar and wait for it to set, for 6-8 days.

The second option is that the pipe is poured with concrete by only a third, then it is raised by 100-150 mm, so the concrete remains at the bottom and forms a kind of pile in the form of an expansion that will prevent the pipe from rising up. The fittings in this case should not protrude beyond the base of the pipe. Raised pipes must be at the same level. Next, the pipe is poured with concrete mortar to the top, and a hairpin is installed on top, which protrudes from the pipe by 300 mm, it is from it that the grillage will be formed.

The second option has the main advantage that the stud has a thread, from which it is easier to form a grillage than from reinforcement. If work is carried out on soils with high flowability, then before installing the pipe, care should be taken to prepare a sand and gravel cushion, on top of which roofing material is laid.

Fittings for installation in pipes must undergo special treatment with the help of protective agents that will prevent premature wear due to corrosion.

The construction of the foundation of plastic pipes

The construction of such a foundation should begin with marking and leveling the site. The plot is traced by level. For marking, pegs and a rope on which they are stretched are used. If there are any kind of elevations or recesses, take care of their alignment.

Dig a small trench around the perimeter and locate the pipes in it. The spacing between pipes is affected by the type of building and its weight. The maximum spacing between plastic pipes is 200 cm.

Pipes in without fail should be present on corner sections, walls and partitions, if there is a terrace or veranda in the house, separate pipes should also be installed under them. Thus, the deformation of the building and its uneven shrinkage will be prevented.

At the bottom of the well, a pillow of sand and gravel is installed, they will serve as drainage. Next, a waterproofing layer is installed in the form of roofing felt or polyethylene film.

Next, a concrete solution is poured into the well, after that, you need to wait an hour until the mixture sets. Next, the pipe is installed and pressed in until it stops. Reinforcing bars are installed in the pipe, which are also pressed into the pipe. Please note that the rods should extend beyond the pipes by 20-25 cm. Sand previously moistened with water is used to fill the free space in the pipe. In order for the concrete mixture to harden, you need to wait a week.

Do-it-yourself columnar foundation made of pipes: metal pipes

When choosing metal pipes for arranging the foundation, there are two ways to carry out this process:

1. The first option involves the installation of pipes, lower from the place where the drilling of the well was completed, about half a meter. The diameter of such a pipe does not have to be 200-250 mm; it is possible to install two or three pipes with a smaller diameter. In this case, the distance between the pipes should be about 5 cm. Further, the pit and pipes are poured with concrete mortar. This method involves the manufacture of a grillage using a steel profile that was previously welded to the pipe. This method is characterized by the highest reliability of fastening and provides maximum strength of the foundation.

2. The second method involves the arrangement of a sand and gravel cushion and the installation of a pipe. Its diameter is 150-200 cm. Please note that the pipe must fit snugly against the well, therefore, in the process of drilling it, the base should be reduced by a few millimeters. In too hot weather metal is prone to thermal expansion, it is this action that will help prevent damage to the foundation. Next, a solution of high quality sand and cement is poured into the pipe. If the building will have more than one floor, then care should be taken to additionally strengthen the foundation with reinforcement.

When the foundation of metal pipes hardens, after five to seven days, the arrangement of the grillage begins. The cheapness and ease of arrangement is distinguished by the use of wood flooring, for the manufacture of which screw connections are used.

When building a residential building, it is better to use metal flooring or concrete casting.

It is the grillage that is able to connect any pipes in one plane. In addition, all walls rest on it and the load is distributed. The grillage is 10-20 cm above the ground.

Used to make a structure monolithic reinforced concrete or metal. If the first option was chosen, then in the process of constructing the grillage, special attention should be paid to the formwork. It must withstand a large load from the concrete solution and not be damaged. If the cross section of the grillage is 250x300 mm, then the formwork is constructed from spacers, the interval between which is half a meter.

To begin with, the upper edge is set, the evenness of which is checked using a bubble level. A polyethylene film is additionally laid along the formwork, it will prevent the spill of cement laitance. Next, a double reinforcing frame made of a metal rod is laid. concrete mortar it is poured twice, first, with a thickness of 10-15 cm, and then to the top. To insulate connections with the foundation, it is recommended to install a pick-up, which is mounted on a sand and gravel dressing.

Strengthening and cost of the foundation of pipes

Please note that non-compliance with the technology of building a foundation from pipes leads to its distortion and deformation of the entire building, so this type of foundation needs to be strengthened.

In order to strengthen the foundation made of steel pipes in a problem area, weld steel profiles to the pipe, which will provide additional rigidity.

Pipes made of plastic or asbestos are reinforced with additional trenches, which are poured with concrete mortar.

A more expensive, but no less effective way to strengthen the foundation of asbestos pipes is to drill holes in the upper part of the pipes and install anchors in them, into which reinforced rods are installed.

If the building sank too much, then it is raised with special equipment, and a trench breaks out on the site to equip the strip foundation.

The cost of a pipe foundation is much lower than that of a strip foundation. For its construction, you should choose cement of a grade not lower than 400. In addition, you will need at least a ton of sand and gravel. The amount of materials depends on the depth of the wells, the number of pipes and the total load on the structure.

When choosing pipes, you should proceed from the same factors. The cheapest option is plastic pipes. In addition, they do not need additional transportation costs.

Asbestos pipes are half the price of plastic pipes; when choosing them, it is better to focus on long products, which, if necessary, will be sawn into several parts. In addition, fittings will be needed to strengthen the pipes.

Buying pipes made of steel is a more expensive process. Although they do not need additional reinforcement with reinforcement.

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