Pipes

Water culverts: appointment, types, application

November 29, 2019

Water culverts are artificial structures, which are laid under the highway or railway line and are used for the passage of sewage. Water can pass through such pipes continuously or at certain intervals. Also, such pipes can serve as a passage tunnel for people.

Water culverts are most often installed under automobiles and railways to drain water and prevent embankment erosion.

Features and benefits of culverts

The culvert allows you to arrange drainage under the car or rail. Most often, such a structure is mounted to divert a stream or riverbed of a small river. Such a pipeline is used in cases, when it is necessary to drain rain and melt water.

Importantly! With a small height of the embankment, it is not possible to organize a full-fledged bridge, therefore, the culvert in this case is the only way out.

Consider the main advantages of using a culvert:

  • the use of such pipes in the roadway not only solves the problem of water drainage, but also allows you to strengthen the embankment. This increases the strength of the road and reduces the risk of destruction of the embankment.
  • budget of the device of the culvert, compared to the bridge, saves on road construction.
  • the possibility of installing a culvert after the construction of the embankment. Installing a bridge in this case is often simply impossible or much more expensive.
  • increased speed of installation work.

The positive aspects of the installation of these structures largely depend on the case and the material, from which the culvert is made.

Types of culverts

All culverts are classified according to several main criteria.

Pipes for culverts can be made of different materials, including polymers

Culverts can be made of the following materials:

  • metal;
  • concrete;
  • reinforced concrete (Reinforced concrete);
  • from polymeric material.

By cross sections, depending on their shape, culverts happen:

  • rectangular;
  • round;
  • oval.

By the number of points in the sections:

  • one-point;
  • two-pointed;
  • polygonal.

exept this, there is a division of culverts for cross-sectional work. However, this parameter is taken into account only in this case, if hydraulic calculation of pipes is carried out.

Consider the types of culverts on the work of the cross section:

  • безнапірні;
  • semi-pressure;
  • pressure head.

Pressure products work on all area of ​​the section, thereby creating maximum throughput. Semi-pressure work the entire cross section only in the area of ​​the pipe head. Pressureless constantly work only part of the section.

Pressureless pipes pass a small amount of drain and are installed there, where water volumes are small

Dimensions

Water-permeable constructions with round section, mounted under the canvas or rail, may have the following diameters:

  • 500 mm - the length of such pipes depends on the case and is calculated based on the width of the road;
  • 750 mm - such pipes can be up to 15 m;
  • 1000 mm - construction, having such a diameter, should not be longer than, than 30 m.

Design for domestic type of roads, may have an intersection 500 mm and a length of up to 10 m.

Features of reinforced concrete pipes

To date, the cost of concrete and reinforced concrete structures is considered the most budget of all possible options. The low price of these materials is a determining factor for many construction companies. exept this, such structures have excellent strength and tightness.

Reinforced concrete culverts are stronger, in comparison with concrete products. The main advantage of reinforced concrete pipes is the ability to organize their production at the installation site (on the road). Otherwise, their transportation is performed using special lifting machines.

As mentioned above, culvert can be used not only for drainage, but also to perform the function of a pedestrian crossing. The diameter of the channel can be from 500 to 4000 mm. exept this, it is worth noting that fact, that water-permeable concrete pipes can be used in seismically active areas. Studies have shown, that regardless of the diameter, the drainage canal can withstand even strong earthquakes (to 9 points on the Richter scale).

Reinforced concrete pipes are of high strength and can be used in seismically active regions

Such pipes are made in the form of separate segments. Links of reinforced concrete culverts can have a length of 1 to 4 m. Reinforced concrete products are regulated by GOST 24547-81.

Polymer pipes

Today, polymer products are becoming increasingly popular. exept this, possibilities of modern productions allow to let out polymeric pipes, which have high strength characteristics and can replace reinforced concrete or metal pipes. However, the weight of polymer products is much lower compared to other materials, which facilitates transportation and installation work.

However, despite the high performance, plastic culverts are mounted in iron arches. Metal structures allow to protect the building from collapse.

In some cases, a special stone arch or gabion box is built around the plastic channel. The result is a solid structure, which is able to withstand heavy loads and has a corrosion-resistant polymer core. The service life of such a structure under normal conditions can reach more than ten years.

Metal culverts

Metal structures have a corrugated body and are the strongest. Such culverts are able to withstand enormous loads, however, such pipes have one major drawback - they are prone to corrosion.

Metal pipes are subject to corrosion, therefore used as temporary structures

Useful Information! Due to rust metal culverts, usually, used as temporary structures.

The most popular option for using such pipes is a temporary passage under the highway. Passages are made to divert water from one side of the road to the other. This need often arises in the event of clogging or collapse of the main culvert. exept this, the metal pipe can be used as a protective case for the polymer pipeline, which is resistant to corrosion.

Corrugated iron culverts are also used to reinforce well walls. Sometimes from such pipes nevertheless mount a constant design, however, this is extremely rare.

Metal drainage channels from separate segments are collected. Collection, usually, performed at the installation site. It is also worth noting, that such pipes can have almost any shape in the finished form. It has to do with that, that they have corrugated walls, which are able to bend. If the metal sheets have a protective anti-corrosion layer, such a design can last up to 50 years. The cost of installing a drainage metal channel on 20-30% lower, than reinforced concrete.

Production technology

Enterprises, which produce similar pipes, follow a number of important rules:

  • each constituent element (link) pipes must be tested for compliance with DSTU standards. According to GOST, the length of the link may deviate from 0 to 10 mm. The thickness of the walls can also be with some deviation - from 5 to 10 mm. Other indicators may have an error of 10 mm;
  • the joints of all elements must be cleaned of inflows, as well as concrete spray, which could be formed in the production process. The cleanliness of the joints is a necessary parameter, which affects the tightness of the connection of the links;
  • sorting of individual items should be carried out according to the brand. After that, all sorted items must be moved to one place.

Manufactured reinforced concrete pipes are tested on many parameters, which must meet GOST standards

Thus production finishing and sorting of separate products for culverts is carried out.

pay attention! Transport these items to the place, where the installation work will take place, is carried out in accordance with the necessary rules, to prevent damage to products. All products are delivered to the installation site in the same form, in which it was delivered after sorting ??in stock.

Preparatory work must be carried out before installation.

Preparatory work before installation

At the very beginning, before installation of the culvert, site selection is carried out, on which construction will later unfold. After, as the desired location is selected, it is cleaned of foreign objects (herbs, branches, garbage, etc.. D.).

Then all the components of the future culvert are decomposed in the correct sequence for further assembly. Before assembly, it is necessary to make the appropriate markings and determine the axis of the product, as well as the contour of the pit. exept this, all necessary calculations are performed before the preparatory work (including hydraulic calculation). All this is needed for that, that in the course of installation there were no unforeseen situations, the normal operation of the culvert also depends on this in the future.

nuances of installation

The excavation work is carried out using special equipment, however, alignment of the pit walls is performed manually (with shovels). If, if the soil at the bottom of the pit is unstable and soft, it is paved. It is laid over the entire area of ​​the bottom of the pit with the use of special tools.

Preparation of the pit for pipes is carried out using equipment

Excavation of the pit is carried out without the installation of special fences, but in some cases fences are still needed. Example, if the pit is sprayed with sewage. Quite often the workers are faced with the need to strengthen the walls of the pit. Such reinforcement is carried out taking into account building codes and safety rules in those cases, when residential or industrial buildings are located near the pit being developed.

The dimensions of the pit, usually, depend on the specific case and are determined taking into account the diameter and shape of the cross section of the culvert. The angles of the slopes of this structure are directly dependent on the properties of a particular soil, in the conditions of which installation works are carried out.

Importantly! When installing a pit under the culvert, it is necessary to anticipate and conveniently plan the location of the pipe, that in case of breakage of the culvert the pipeline was available for repair work.

One important rule to keep in mind when installing waterproofing or anti-corrosion protection is that the distance between the foundation walls and the pit walls must not be less than 70 cm. This is necessary for the convenience of work, after all, these procedures are performed by workers. If the use of people is not mandatory - this figure is reduced to 10 cm. It is also worth noting, that in the absence of the need for arrangement of the foundation, the pit for the culvert is dug exactly to the size of the pipe.

foundation installation

If, if the foundation consists of prefabricated reinforced concrete slabs, then first of all installation of links is carried out, which will form the head of the future culvert. Laying of blocks is carried out to the level of a sole, and then work is done to fill the sinuses to the same level.

Concrete blocks or slabs are used for foundation installation

Consider the main stages of arrangement of the monolithic foundation:

  1. First of all it is necessary to make or buy already ready timbering.
  2. Next, prepare the necessary concrete solution for pouring.
  3. In the third stage, pre-prepared concrete mortar is poured into the formwork.
  4. When the solution hardens, it is necessary to dismantle a timbering and to fill in the formed sinuses.

Installation of a culvert

Before carrying out installation works it is necessary to clear all elements of a design (links, blocks, etc.. D.) From dirt. If the installation is carried out in winter, then you need to clean all products from snow and ice. After that, you can proceed directly to the installation. Installation is performed in three stages:

  1. Structural elements, which have flat faces, mounted on cement mortar. Cylindrical parts of the culvert are installed on special wooden substrates. After this, under the cylindrical links pour the solution.
  2. Pouring the solution is carried out on one side until then, until he appears on the other side. Due to this, the alignment and complete filling of all seams in the structure is achieved. If concreting is carried out for each link separately - use a solution with mobility on the reference cone in 12 cm.
  3. After, as the concreting of the culvert is completed, its waterproofing is carried out. It is carried out with the help of mastic.

Repair of culverts

To date, there are several basic options for repairing culverts. Usually, repair of culverts is performed by the pitless method. That is, repair work is carried out without digging out the pipe from the pit. The pit method is used much less often - in those cases, when a complete pipeline replacement is required.

Restoration of channel functions can be carried out by means of a new pipe, which is simply inserted into the old one

Consider the main options for repairing culverts:

  • sanitation;
  • SPR technology;
  • relay;

exept this, there is another way to repair such pipes - microtunnel, however, it is used very rarely due to the high cost of equipment. Besides, one set of equipment is suitable only for a certain diameter of the pipe with a round cross-section.

sanitation

Rehabilitation is a way, based on pushing plastic sleeves inside the repaired culvert. After, as the sleeve stretch is complete, air is pumped into it in order to create excess pressure. Sleeve, inflated with air, repeats the shape of the pipe from the inside. Then it is irradiated with ultraviolet rays. As a result, the sleeve hardens and forms a kind of additional framework, which not only repairs the pipe, but also strengthens the strength of the structure as a whole. The wall thickness of such a sleeve is approximately 8 mm.

pay attention! All repair work takes only a few hours, therefore, this method of repairing the culvert is very popular.

SPR

SPR technology is a way to repair culverts, which have large diameter values. exept this, this technology is used to repair pipes not only with a round shape of the section, but also for others.

The repair process for this technology takes place in 2 stages:

  1. Inside the repaired channel wind the profile. Profile, usually, made of polyvinyl chloride (Pvc) and is reinforced with special inserts.
  2. The solution is poured into the gap between the repaired pipe and the housing.

After repair using SPR technology, bearing performance indicators increase in 2-3 times.

Relaying

Relining is performed by laying a new one in the old culvert, which is made of fiberglass. Inside there is a joining of links, and then the gap between the two walls is filled, as in the previous case, cement mortar.

It is worth noting, that in the world there are many technologies for the repair of culverts, however the most popular, time-tested methods are only a few and they are used almost all over the world.