As the power lines are indicated on the diagrams. Types and types of supports for overhead power lines
Depending on the method of suspension of wires, the supports of overhead lines (VL) are divided into two main groups:
a) intermediate supports, on which the wires are fixed in supporting clamps,
b) anchor type supports used to tension the wires. On these supports, the wires are fixed in tension clamps.
The distance between the supports (power lines) is called the span, and the distance between the anchor type supports is anchored section(Fig. 1).
According to the intersection of some engineering structures, for example railways general use, must be performed on anchor-type supports. At the corners of the line, corner supports are installed, on which the wires can be suspended in support or tension clamps. Thus, the two main groups of supports - intermediate and anchor - are divided into types that have a special purpose.
Rice. 1. Scheme of the anchored section of the overhead line
Intermediate straight supports are installed on straight sections of the line. On intermediate supports with suspension insulators, the wires are fixed in supporting garlands hanging vertically; on intermediate supports with pin insulators, the wires are fixed by wire knitting. In both cases, intermediate supports perceive horizontal loads from wind pressure on the wires and on the support, and vertical - from the weight of wires, insulators and the own weight of the support.
With unbroken wires and cables, intermediate supports, as a rule, do not perceive the horizontal load from the tension of wires and cables in the direction of the line and therefore can be made of a lighter design than other types of supports, for example, end supports that perceive the tension of wires and cables. However, to ensure reliable operation line intermediate supports must withstand some load in the direction of the line.
Intermediate corner supports installed at the corners of the line with a suspension of wires in supporting garlands. In addition to the loads acting on the intermediate straight supports, the intermediate and anchor angle supports also perceive loads from the transverse components of the tension of the wires and cables.
At angles of rotation of the power line of more than 20 °, the weight of the intermediate corner supports increases significantly. Therefore, intermediate corner supports are used for angles up to 10 - 20°. At large angles of rotation, anchor angle supports.
Rice. 2. Intermediate supports VL
Anchor supports. On lines with suspension insulators, the wires are fixed in the clamps of the tension garlands. These garlands are, as it were, a continuation of the wire and transfer its tension to the support. On lines with pin insulators, the wires are fixed on anchor supports with reinforced viscous or special clamps that ensure the transfer of the full tension of the wire to the support through the pin insulators.
When installing anchor supports on straight sections of the route and suspending wires on both sides of the support with the same tensions, the horizontal longitudinal loads from the wires are balanced and the anchor support works in the same way as the intermediate one, i.e. it perceives only horizontal transverse and vertical loads.
Rice. 3. Anchor-type overhead line supports
If necessary, the wires on one and the other side of the anchor support can be pulled with different tension, then the anchor support will perceive the difference in tension of the wires. In this case, in addition to horizontal transverse and vertical loads, the horizontal longitudinal load will also act on the support. When installing anchor supports at the corners (at the turning points of the line), the anchor corner supports also perceive the load from the transverse components of the tension of the wires and cables.
End supports are installed at the ends of the line. From these supports depart wires suspended on the portals of substations. When hanging wires on the line until the end of the construction of the substation, the end supports perceive full one-sided tension.
In addition to the listed types of supports, special supports are also used on the lines: transpositional, serving to change the order of the wires on the supports, branch - to carry out branches from the main line, support for large crossings over rivers and water spaces, etc.
The main type of supports on overhead lines are intermediate ones, the number of which usually makes up 85-90% of the total number of supports.
According to the design of the support can be divided into free-standing and braced supports. Guys are usually made of steel cables. On overhead lines, wooden, steel and reinforced concrete supports are used. Designs of supports made of aluminum alloys have also been developed.
Structures of overhead lines
- Wooden support LOP 6 kV (Fig. 4) - single-column, intermediate. It is made of pine, sometimes larch. The stepson is made of impregnated pine. For 35-110 kV lines, wooden U-shaped two-column supports are used. Additional elements support structures: hanging garland with hanging clip, traverse, braces.
- Reinforced concrete supports are made as single-column free-standing, without braces or with braces to the ground. The support consists of a post (trunk) made of centrifuged reinforced concrete, a traverse, a lightning protection cable with a ground electrode on each support (for lightning protection of the line). With the help of a grounding pin, the cable is connected to a grounding conductor (a conductor in the form of a pipe hammered into the ground next to the support). The cable serves to protect the lines from direct lightning strikes. Other elements: rack (trunk), traction, traverse, cable rack.
- Metal (steel) supports (Fig. 5) are used at a voltage of 220 kV or more.
STATE STANDARD OF THE UNION OF THE SSR
UNIFIED SYSTEM OF TECHNOLOGICAL DOCUMENTATION
SUPPORTS, CLIPS
AND INSTALLATION DEVICES.
GRAPHIC SYMBOLS
GOST 3.1107-81
(CTCMEA 1803 -7 9)
STATE STANDARD OF THE UNION OF THE SSR
|
Unified system of technological documentation SUPPORTS, CLIPS Unified system for technological documentation. |
GOST (CTCMEA 1803 -7 9) Instead |
from 01.07.82
1. This standard establishes graphic symbols for supports, clamps and mounting devices used in technological documentation. The standard fully complies with ST SEV 1803-7 9. 2. To depict the designation of supports, clamps and mounting devices, a solid thin line should be used in accordance with GOST 2.303-68. 3. Designations of supports (conditional) are given in table. one.
Table 1
|
On and changing support |
Support designation in views |
||
|
front and back |
|||
| 1. Fixed | |||
| 2. Movable |
|
||
| 3. Floating |
|
||
| 4. Adjustable |
|
||
table 2
|
Clamp name |
Clamp designation on views |
||
|
front, back |
|||
| 1. Single | |||
| 2. Double |
|
|
|
Table 3
|
Installation device name |
Designation of the installation device on the views |
||
|
front, back, top, bottom |
|||
| 1. The center is fixed |
|
No designation |
No designation |
| 2. Rotating center |
|
||
| 3. Center floating |
|
||
| 4. Cylindrical mandrel |
|
||
| 5. Ball mandrel (roller) |
|
||
| 6. Driver chuck | |||
Table 4
|
Name of the form of the working surface |
Designation of the shape of the working surface on all in and das |
| 1. Flat |
|
| 2. Spherical |
|
| 3. Qi l indricheskaya (ball ovaya) | |
| 4. Pr and zmatic | |
| 5. Conical | |
| 6. Rhombic |
|
| 7. Triangular |
Table 5
15. The designation of the types of clamp devices is applied to the left of the designation of the clamps (reference appendices 1 and 2). Note. For g and droplast mandrels, it is allowed to use the designation e -. 16. The number of points of application of the clamping force to the product, if necessary, should be written to the right of the clamp designation (reference appendix 2, pos. 3). 17. On diagrams that have several projections, it is allowed not to indicate on separate projections the designations of supports, clamps and mounting devices relative to the product, if their position is unambiguously determined on one projection (reference appendix 2, item 2). 18. On the diagrams, it is allowed to replace several designations of the same supports on each type with one, with the designation of their number (reference appendix 2, pos. 2). 19. Deviations from the sizes of the graphic designations specified in tab. 1 - 4 and in the drawing.ATTACHMENT 1
Reference
Examples of designations for supports, clamps and mounting devices on diagrams
|
Name |
Examples of naming supports, clamps and mounting devices |
| 1. The center is fixed (smooth) |
|
| 2. Center grooved |
|
| 3. Center floating |
|
| 4. Rotating center |
|
| 5. Center reverse rotating with corrugated surface |
|
| 6. Driver chuck |
|
| 7. Steady rest |
Types of overhead lines
In the production of metal structures for power lines There are the following types of overhead lines:
intermediate power transmission towers,
power line anchor supports ,
power line corner poles and special hardware for power lines. Varieties of types of structures of overhead power lines, which are the most numerous on all power lines, are intermediate supports that are designed to support wires on straight sections of the route. All high-voltage wires are attached to power transmission traverses through supporting insulator garlands and other structural elements of overhead power lines. In normal mode, this type of overhead line supports perceive loads from the weight of adjacent half-spans of wires and cables, the weight of insulators, linear fittings and individual support elements, as well as wind loads due to wind pressure on wires, cables and the metal structure of the power transmission line itself. In emergency mode, the structures of intermediate supports of power transmission lines must withstand the stresses that occur when one wire or cable breaks.
The distance between two adjacent intermediate supports VL called an intermediate span. Corner supports VL can be intermediate and anchor. Intermediate corner elements of power transmission lines are usually used at small angles of rotation of the route (up to 20 °). Anchor or intermediate corner elements of power transmission lines are installed in sections of the line route where its direction changes. Intermediate corner supports of overhead lines in normal mode, in addition to loads acting on ordinary intermediate elements of power lines, perceive the total effort from the tension of wires and cables in adjacent spans, applied at the points of their suspension along the bisector of the angle of rotation of the power line. The number of anchor corner supports of overhead lines is usually a small percentage of the total number on the line (10 ... 15%). Their use is determined by the conditions of installation of lines, the requirements for the intersection of lines with various objects, natural obstacles, i.e. they are used, for example, in mountainous areas, and also when intermediate corner elements do not provide the required reliability.
Are used anchor angle supports and as terminal wires from which the wires of the line go to the switchgear of the substation or station. On lines passing in populated areas, the number of anchor corner elements of power lines also increases. The wires of the overhead line are fastened through the tension garlands of insulators. In normal mode, these power line supports , in addition to the loads indicated for the intermediate elements of the stucco, there is a difference in tension along the wires and cables in adjacent spans and the resultant of the gravitational forces along the wires and cables. Usually, all anchor-type supports are installed so that the resultant of the gravitational forces is directed along the axis of the support traverse. In emergency mode, the anchor posts of power lines must withstand the breakage of two wires or cables. The distance between two adjacent anchor supports of power lines called an anchor span. Branching elements of power transmission lines are designed to carry out branches from main overhead lines, if necessary, to supply electricity to consumers located at some distance from the route. Cross elements are used to cross wires of overhead lines in two directions on them. End racks of overhead lines are installed at the beginning and end of the overhead line. They perceive the forces directed along the line, created by the normal one-sided tension of the wires. For overhead lines, power transmission line anchor supports are also used, which have increased strength compared to the types of racks listed above and a more complex design. For overhead lines with voltages up to 1 kV, reinforced concrete racks are mainly used.
What are power transmission towers? Classification of varieties
According to the method of fixing in the ground, they are classified:
VL supports installed directly into the ground - Power transmission line supports installed on foundations Varieties of power transmission line supports by design:
Free-standing power line poles - Guyed poles
By the number of circuits, power transmission towers are classified:
Single circuit - Double circuit - Multi circuit
Unified transmission line poles
Based on many years of practice in the construction, design and operation of overhead lines, the most appropriate and economical types and designs of supports for the corresponding climatic and geographical regions are determined and their unification is carried out.
Designation of power transmission towers
For metal and reinforced concrete supports of 10 - 330 kV overhead lines, the following designation system is adopted.
P, PS - intermediate supports
PVS - intermediate supports with internal connections
PU, PUS - intermediate corner
PP - intermediate transitional
U, US - anchor-angular
K, KS - terminal
B - reinforced concrete
M - Polyhedral
How are overhead lines marked?
The numbers after the letters in the marking indicate the voltage class. The presence of the letter "t" indicates a cable rack with two cables. The number through a hyphen in the marking of the overhead line supports indicates the number of circuits: odd, for example, a unit in the numbering of a power transmission line support is a single-circuit line, even number in numbering - two and multi-stranded. The number through "+" in the numbering means the height of the attachment to the base support (applicable to metal).
For example, symbols for overhead lines: U110-2+14 - Metal anchor-angled double-chain support with stand 14 meters PM220-1 - Intermediate metal multi-faceted single-chain support U220-2t - Metal anchor-angled double-chain support with two cables
Overhead power lines. Support structures.
Supports and foundations for overhead power lines with a voltage of 35-110 kV have significant specific gravity both in terms of material consumption and cost. Suffice it to say that the cost of the mounted support structures on these overhead lines is, as a rule, 60-70% of the total cost of the construction of overhead power lines. For lines located on industrial enterprises and the territories immediately adjacent to them, this percentage may be even higher.
Overhead line supports are designed to support line wires at a certain distance from the ground, ensuring the safety of people and reliable operation of the line.
Overhead power line towers are divided into anchor and intermediate. The supports of these two groups differ in the way the wires are suspended.
Anchor supports completely perceive the tension of wires and cables in spans adjacent to the support, i.e. serve to stretch the wires. On these supports, the wires are suspended with the help of hanging garlands. Anchor type supports can be of normal and lightweight construction. Anchor supports are much more complicated and more expensive than intermediate ones, and therefore their number on each line should be minimal.
Intermediate supports do not perceive the tension of the wires or perceive it partially. On the intermediate supports, the wires are suspended with the help of insulators supporting garlands, fig. one.
Rice. one. Scheme of the anchor span of the overhead line and the span of the intersection with the railway
On the basis of anchor supports can be performed end and transposition supports. Intermediate and anchor supports can be straight and angled.
End anchor supports installed at the exit of the line from the power plant or at the approaches to the substation are in the worst conditions. These supports experience one-sided tension of all wires from the side of the line, since tension from the side of the substation portal is insignificant.
Intermediate lines supports are installed on straight sections of overhead power lines to support wires. An intermediate support is cheaper and easier to manufacture than an anchor one, since in normal mode it does not experience forces along the line. Intermediate supports make up at least 80-90% of the total number of overhead line supports.
Angle supports are set at the turning points of the line. At angles of rotation of the line up to 20 °, angled anchor-type supports are used. At angles of rotation of the power line more than 20 ° - intermediate corner supports.
On overhead power lines are used special supports the following types: transpositional- to change the order of the wires on the supports; branch- to carry out branches from the main line; transitional- for crossing rivers, gorges, etc.
Transposition is used on lines with a voltage of 110 kV and above with a length of more than 100 km in order to make the capacitance and inductance of all three phases of the overhead power transmission line circuit the same. At the same time, the relative position of the wires in relation to each other is consistently changed on the supports. However, such a triple movement of wires is called a transposition cycle. The line is divided into three sections (steps), in which each of the three wires occupies all three possible positions, fig. 2.
Rice. 2. Single Circuit Wire Transposition Cycle
Depending on the number of chains suspended on the supports, the supports can be single and double chain. The wires are located on single-circuit lines horizontally or in a triangle, on double-circuit supports - reverse tree or hexagon. The most common arrangements of wires on supports are schematically shown in fig. 3.
Rice. 3. The most common arrangement of wires and cables on supports:
a - location along the vertices of the triangle; b - horizontal arrangement; in - the location of the reverse Christmas tree
The possible location of lightning protection cables is also indicated there. The location of the wires along the vertices of the triangle (Fig. 3, a) is widespread on lines up to 20-35 kV and on lines with metal and reinforced concrete supports with a voltage of 35-330 kV.
The horizontal arrangement of wires is used on 35 kV and 110 kV lines on wooden poles and on higher voltage lines on other poles. For double-circuit supports, the arrangement of wires according to the "reverse tree" type is more convenient from the point of view of installation, but it increases the mass of the supports and requires the suspension of two protective cables.
wooden supports were widely used on overhead power lines up to 110 kV inclusive. Pine poles are the most common, and larch poles are somewhat less common. The advantages of these supports are low cost (in the presence of local wood) and ease of manufacture. The main disadvantage is the decay of wood, which is especially intense at the point of contact of the support with the soil.
Metal supports are made of steel of special grades for lines of 35 kV and above, require a large amount of metal. Individual elements connected by welding or bolts. To prevent oxidation and corrosion, the surface of metal supports is galvanized or periodically painted with special paints. However, they have high mechanical strength and long service life. Install metal supports on reinforced concrete foundations. These supports, according to the constructive solution of the support body, can be attributed to two main schemes - tower or single rack, rice. 4, and portal, rice. 5.a, according to the method of fixing on the foundations - to free-standing supports, fig. 4 and 6, and braced supports, rice. 5.a, b, c.
On metal poles with a height of 50 m or more, ladders with railings reaching the top of the pole should be installed. At the same time, platforms with fences should be made on each section of the supports.
Rice. four. Intermediate metal support of single circuit line:
1 - wires; 2 - insulators; 3 - lightning protection cable; 4 - cable rack; 5 - support traverses; 6 - support post; 7 - support foundation
Rice. 5. Metal supports:
a) - intermediate single-circuit on braces 500 kV; b) - intermediate V-shaped 1150 kV; c) - intermediate support of 1500 kV direct current overhead lines; d) - elements of spatial lattice structures
Rice. 6. Metal free-standing double chain poles:
a) - intermediate 220 kV; b) - anchor angle 110 kV
Reinforced concrete supports are performed for lines of all voltages up to 500 kV. To ensure the required density of concrete, vibrocompaction and centrifugation are used. Vibrocompaction is performed by various vibrators. Centrifugation provides very good compaction of concrete and requires special machines - centrifuges. On overhead power lines of 110 kV and above, the pillars and traverses of portal supports are centrifuged pipes, conical or cylindrical. Reinforced concrete supports are more durable than wooden ones, there is no corrosion of parts, they are easy to operate and therefore received wide use. They have a lower cost, but have a greater mass and relative fragility of the concrete surface, Fig. 7.
Rice. 7. Intermediate reinforced concrete free-standing single-circuit
supports: a) - with pin insulators 6-10 kV; b) - 35 kV;
c) - 110 kV; d) - 220 kV
Traverses of single-column reinforced concrete supports are galvanized metal.
The service life of reinforced concrete and metal galvanized or periodically painted supports is long and reaches 50 years or more.
All objects on the ground, the situation and characteristic forms of relief are displayed on topographic plans with conventional signs.
Symbols on topographic survey
The main four types into which conventional signs are divided:
- Explanatory captions.
- Linear symbols.
- Areal (contour).
- Off-scale.
Explanatory captions are used to indicate additional characteristics of the depicted objects: near the river they sign the speed of the current and its direction, near the bridge - the width, length and its carrying capacity, near the roads - the nature of the coating and the width of the carriageway itself, etc.
Linear symbols (designations) are used to display linear objects: power lines, roads, product pipelines (oil, gas), communication lines, etc. The width shown on the topoplan of linear objects is off-scale.
Contour or area symbols depict those objects that can be displayed in accordance with the scale of the map and occupy a certain area. The contour is drawn with a thin solid line, broken or depicted as a dotted line. The formed contour is filled with conventional symbols (meadow vegetation, woody, garden, vegetable garden, shrub thickets, etc.).
To display objects that cannot be expressed on a map scale, off-scale conventional symbols are used, while the location of such an off-scale object is determined by its characteristic point. For example: the center of a geodetic point, the base of a kilometer post, the centers of radio, TV towers, pipes of factories and plants.
In topography, displayed objects are usually divided into eight main segments (classes):
- Relief
- Mathematical basis
- Soils and vegetation
- Hydrography
- Road network
- Industrial enterprises
- Settlements,
- Signatures and borders.
Collections of symbols for maps and topographic plans different scales are created in accordance with this division into objects. Approved state. they are the same bodies for all topographic plans and are obligatory when drawing any topographic surveys (topographic surveys).
Common symbols on topographic surveys:
State points. geodetic network and densification points
- Land use and allotment boundaries with landmarks at turning points
- Buildings. Numbers indicate the number of storeys. Explanatory captions are given to indicate the fire resistance of the building (w - residential non-fire-resistant (wooden), n - non-residential non-fire-resistant, kn - stone non-residential, kzh - stone residential (usually brick), smzh and smn - mixed residential and mixed non-residential - wooden buildings with thin cladding brick or with floors built of different materials(the first floor is brick, the second is wooden)). The dotted line shows the building under construction.
- Slopes. They are used to display ravines, road embankments and other artificial and natural landforms with sharp elevation changes.
- Pillars of power transmission lines and communication lines. Conventions repeat the shape of the section of the column. Round or square. At reinforced concrete pillars, there is a dot in the center of the symbol. One arrow in the direction of the electrical wires - low-voltage, two - high-voltage (6kv and above)
- Underground and overground communications. Underground - dotted line, aboveground - solid. The letters indicate the type of communications. K - sewerage, G - gas, H - oil pipeline, V - water supply, T - heating main. Additional explanations are also given: The number of wires for cables, gas pipeline pressure, pipe material, their thickness, etc.
- Various areal objects with explanatory captions. Wasteland, arable land, construction site, etc.
- Railways
- Car roads. The letters indicate the coating material. A - asphalt, Shch - crushed stone, C - cement or concrete plates. On dirt roads, the material is not indicated, and one of the sides is shown as a dotted line.
- Wells and wells
- Bridges across rivers and streams
- Horizontals. They serve to display the terrain. They are lines formed when the earth's surface is cross-sectioned by parallel planes at equal intervals of height change.
- Marks of heights of characteristic points of the terrain. As a rule, in the Baltic system of heights.
- Various tree vegetation. Indicates the dominant species of woody vegetation, the average height of trees, their thickness and the distance between trees (density)
- Free standing trees
- Shrubs
- Various meadow vegetation
- Waterlogged with reed vegetation
- Fences. Fences made of stone and reinforced concrete, wooden, picket fence, chain-link mesh, etc.
Commonly used abbreviations in surveying:
Buildings:
H - Non-residential building.
J - Residential.
KN - Stone non-residential
KZh - Stone residential
PAGE - under construction
FUND. - Foundation
SMN - Mixed non-residential
CSF - Mixed Residential
M. - Metallic
development - Destroyed (or collapsed)
Gar. - Garage
T. - Toilet
Communication lines:
3pr. - Three wires on a power pole
1 cab. - One cable per pole
b/pr - without wires
tr. - Transformer
K - Sewerage
Cl. - Storm sewerage
T - Heating main
H - Oil pipeline
cab. - Cable
V - Communication lines. Numeric number of cables, for example 4V - four cables
n.a. - Low pressure
s.d. - medium pressure
o.d. - High pressure
Art. - Steel
chug - Cast iron
bet. - Concrete
Areal symbols:
bld. pl. - Construction site
og. - vegetable garden
empty - Wasteland
Roads:
A - Asphalt
Shch - Rubble
C - Cement, concrete slabs
D - wood flooring. Almost never occurs.
dor. zn. - Road sign
dor. decree. - Road sign
Water objects:
K - Well
well - well
art.well - artesian well
vdkch. - Water tower
bass. - Swimming pool
vdkhr. - Reservoir
clay - Clay
Symbols may differ on plans of different scales, therefore, to read the topoplan, it is necessary to use the symbols for the appropriate scale.
How to read conventional signs on a topographic survey
Consider how to correctly understand what we see on a topographic survey on specific example and how can we help .
Below is a 1:500 scale topographic survey of a private house with a land plot and the surrounding area.
In the upper left corner we see an arrow with which it is clear how the topographic survey is oriented in the north direction. On a topographic survey, this direction may not be indicated, since by default the plan should be oriented with the upper part to the north.
The nature of the relief in the survey area: the area is flat with a slight decrease to the south. The elevation difference from north to south is approximately 1 meter. The height of the southernmost point is 155.71 meters, and the northernmost point is 156.88 meters. Elevation marks were used to display the relief, covering the entire area of topographic survey and two horizontals. The upper thin one with a mark of 156.5 meters (not signed on topographic survey) and the thickened one located to the south with a mark of 156 meters. At any point lying on the 156th horizontal, the mark will be exactly 156 meters above sea level.
The topographic survey shows four identical crosses located at equal distances in the form of a square. This is a coordinate grid. They serve to graphically determine the coordinates of any point on a topographic survey.
Next, we will sequentially describe what we see from north to south. In the upper part of the topoplan there are two parallel dotted lines with the inscription "Valentinovskaya street" between them and two letters "A". This means that we see a street called Valentinovskaya, the roadway of which is covered with asphalt, without a curb (since these are dashed lines. Solid lines are drawn with the curb, indicating the height of the curb, or two marks are given: the top and bottom of the curb stone).
Let's describe the space between the road and the fence of the site:
- It runs horizontally. The relief goes down towards the site.
- In the center of this part of the survey is concrete pillar power lines, from which cables with wires depart in the directions indicated by the arrows. Cable voltage 0.4kv. There is also a street lamp hanging from the pole.
- To the left of the pillar, we see four broad-leaved trees (it can be oak, maple, linden, ash, etc.)
- Below the pillar, parallel to the road with a branch towards the house, an underground gas pipeline was laid (yellow dotted line with the letter G). The pressure, material and diameter of the pipe are not indicated on the topographic survey. These characteristics are specified after agreement with the gas industry.
- The two short parallel segments encountered in this area of topographic survey are a conventional sign of herbaceous vegetation (forbs)
Let's move on to the site.
The facade of the plot is fenced with a metal fence with a height of more than 1 meter with a gate and a gate. The facade of the left (or right, if you look from the side of the street at the site) is exactly the same. The facade of the right section is fenced wooden fence on a stone, concrete or brick foundation.
Vegetation on the site: lawn grass with free-standing pine trees (4 pieces) and fruit trees(also 4 pieces).
On the site there is a concrete pole with a power cable from the pole on the street to the house on the site. An underground gas branch to the house departs from the gas pipeline route. Underground water supply is brought to the house from the neighboring plot. The fencing of the western and southern parts of the site is made of chain-link mesh, the eastern part is made of metal fence over 1 meter high. In the southwestern part of the site, a part of the fences of neighboring sites from a chain-link mesh and a solid wooden fence is visible.
Buildings on the site: In the upper (northern) part of the site there is a residential one-story wooden house. 8 is the number of the house on Valentinovskaya street. The floor level mark in the house is 156.55 meters. In the eastern part, a terrace with a wooden deck is attached to the house. closed porch. In the western part of the neighboring area there is a destroyed extension to the house. There is a well near the northeast corner of the house. In the southern part of the site there are three wooden non-residential buildings. One of them is attached to a canopy on poles.
Vegetation in neighboring areas: in the area located to the east - woody vegetation, to the west - herbaceous.
On the site located to the south, a residential one-story wooden house is visible.
That's the way help to obtain a sufficiently large amount of information about the territory on which the topographic survey was carried out.
And finally, this is how this topographic survey applied to an aerial photograph looks like: 
People who do not have special education in the field of geodesy or cartography may not understand the crosses depicted on maps and topographic plans. What is this symbol?
This is the so-called coordinate grid, the intersection of integers or exact values coordinates. The coordinates used on maps and topographic maps can be geographic and rectangular. Geographic coordinates are latitude and longitude, rectangular coordinates are distances from the conditional origin in meters. For example, state cadastral registration is carried out in rectangular coordinates, and each region uses its own system of rectangular coordinates, which differs in the conditional origin in different regions of Russia (for the Moscow region, the MSK-50 coordinate system is adopted). For cards on large territories usually use geographical coordinates(latitude and longitude, which you could also see in GPS navigators).
Topographic survey or topographic survey is carried out in a rectangular coordinate system and the crosses that we see on such a topographic map are the intersection points of round coordinate values. If there are two topographic surveys of adjacent sections in the same coordinate system, they can be combined by these crosses and a topographic survey for two sections at once can be obtained, from which you can get more full information about the surrounding area.
Distance between crosses on topographic survey
In accordance with the rules and regulations, they are always located at a distance of 10 cm from each other and form regular squares. By measuring this distance on the paper version of the topographic survey, you can determine whether the scale of the topographic survey is observed when printing or photocopying source material. This distance should always be 10 centimeters between adjacent crosses. If it differs significantly, but not by an integer number of times, then such material cannot be used, since it does not correspond to the declared scale of the topographic survey.
If the distance between the crosses differs by several times from 10 cm, then most likely such a topographic survey was printed out for some tasks that do not require compliance with the original scale. For example: if the distance between crosses on topographic survey 1:500 scale - 5 cm, which means it was printed on a scale of 1:1000, distorting all the symbols, but at the same time reducing the size of the printed material, which can be used as an overview plan.
Knowing the scale of the topographic survey, it is possible to determine what distance in meters on the ground corresponds to the distance between adjacent crosses on the topographic survey. So for the most commonly used topographic survey scale of 1:500, the distance between the crosses corresponds to 50 meters, for a scale of 1:1000 - 100 meters, 1:2000 - 200 meters, etc. This can be calculated knowing that between crosses on topographic survey 10 cm, and the distance on the ground in one centimeter of topographic survey in meters is obtained by dividing the scale denominator by 100.
It is possible to calculate the scale of topographic survey by crosses (coordinate grid) if the rectangular coordinates of adjacent crosses are specified. To calculate, it is necessary to multiply the difference in coordinates along one of the axes of neighboring crosses by 10. Using the example of the topographic survey below, in this case we will get: (2246600 - 2246550)*10= 500 ---> The scale of this survey is 1:500 or centimeter 5 meters. It is also possible to calculate the scale, if it is not indicated on the topographic survey, by the known distance on the ground. For example, according to the known length of the fence or the length of one of the sides of the house. To do this, we divide the known length on the ground in meters by the measured distance of this length on the topographic survey in centimeters and multiply by 100. Example: the length of the wall of the house is 9 meters, this distance measured with a ruler on the topographic survey is 1.8 cm. (9 / 1.8) * 100 =500. Topographic survey scale - 1:500. If the distance measured on the topographic survey is 0.9 cm, then the scale is 1:1000 ((9/0.9)*100=1000)
The use of crosses in topographic survey
The size crosses on topographic survey should be 1cm X 1cm. If the crosses do not correspond to these dimensions, then most likely the distance between them is not observed and the scale of the topographic survey is distorted. As already mentioned, by crosses, in the case of topographic surveys in the same coordinate system, it is possible to combine topographic surveys of neighboring territories. Designers use crosses on topographic surveys to bind objects under construction. For example, for the offset of the axes of buildings, the exact distances along the coordinate axes to the nearest cross are indicated, which makes it possible to calculate the future exact location of the projected object on the ground.
Below is a fragment of a topographic survey with the indicated values of rectangular coordinates on the crosses.
Topographic survey scale
The scale is the ratio of linear dimensions. This word came to us from German language, and translates as "measuring stick".
What is the scale of a topographic survey
In geodesy and cartography, the term scale is understood as the ratio of the real size of an object to the size of its image on a map or plan. The scale value is written as a fraction with a unit in the numerator, and a number in the denominator indicating how many times the reduction was made.
Using the scale, you can determine which segment on the map will correspond to the distance measured on the ground. For example, moving on a 1:1000 scale map by one centimeter will be equivalent to ten meters traveled on the ground. Conversely, every ten meters of terrain is a centimeter of a map or plan. The larger the scale, the more detailed the map, the more fully it displays the objects of the area plotted on it.
Scale one of the key concepts topographic survey. The variety of scales is explained by the fact that each type of it, focused on solving specific problems, makes it possible to obtain plans of a certain size and generalization. For example, large-scale ground surveys can provide a detailed display of the terrain and objects located on the ground. It is done in the production of land management works, as well as in engineering and geodetic surveys. But she will not be able to show objects on the same large area like small-scale aerial photography.
The choice of scale, first of all, depends on the degree of detail of the map or plan required in each particular case. The larger the scale used, the higher the requirements for the accuracy of measurements. And the performers and specialized enterprises that carry out this survey should have all the more experience.
Scale types
There are 3 types of scale:
Named;
Graphic;
Numerical.
Topographic survey scale 1:1000
used in the design of low-rise construction, in engineering surveys. It is also used for drawing up working drawings. various objects industry.
Smaller scale 1:2000 suitable, for example, for detailing individual sections of settlements - cities, towns, rural areas. It is also used for projects of fairly large industrial facilities.
to scale 1:5000 constitute cadastral plans, master plans of cities. It is indispensable in the design of railways and highways, laying communication networks. It is taken as the basis for the preparation of small-scale topographic plans. Smaller scales, starting from 1:10000, are used for plans of the largest settlements - cities and towns.
But most in demand uses topographic surveying to scale 1:500 . The range of its use is quite wide: from the general plan of the construction site, to ground and underground engineering communications. Larger scale work is required only in landscape design, where ratios of 1:50, 1:100 and 1:200 are needed to describe the terrain in detail - separately standing trees, bushes and other similar objects.
For topographic surveys at a scale of 1:500, the average errors of contours and objects should not exceed 0.7 mm, no matter how difficult the nature of the terrain and relief. These requirements are determined by the specifics of the application area, which includes:
engineering communications plans;
drawing up very detailed plans for industrial and household buildings;
improvement of the territory adjacent to the buildings;
laying out gardens and parks;
landscaping of small areas.
Such plans depict not only the relief and vegetation, but also water bodies, geological wells, reference points and other similar structures. One of the main features of this large-scale topographic survey is the application of communications, which must be coordinated with the services operating them.
Do-it-yourself topographic survey
Is it possible to do a topographic survey of your own site with your own hands, without involving a specialist in the field of geodesy? How difficult is it to do a topographic survey on your own.
In the event that topographic survey is necessary to obtain any official documents, such as a building permit, granting ownership or rent land plot or receiving specifications for connection to gas, electricity or other communications, you will not be able to provide do-it-yourself survey. In this case, topographic survey is an official document, the basis for further design, and only specialists who have a license to carry out geodetic and cartographic work or are members of a self-regulatory organization (SRO) corresponding to these types of work have the right to perform it.
Run do-it-yourself surveying without special education and work experience is almost impossible. Topographic survey is a rather technically complex product that requires knowledge in the field of geodesy, cartography and the availability of special expensive equipment. Possible errors in the received topoplan can lead to serious problems. For example, an incorrect determination of the location of a future building due to poor-quality topographic survey can lead to a violation of fire and building codes and as a consequence to a possible court decision on the demolition of the structure. Topographical surveys with gross errors can lead to an incorrect location of the fence, violating the rights of the neighbors of your land and, as a result, to its dismantling and significant additional costs for its construction in a new location.
In what cases and how can you do topographic survey with your own hands?
The result of the topographic survey is detailed plan terrain, which displays the relief and the detailed situation. Special geodetic equipment is used to plot objects and terrain on the plan.
Devices and tools that can be used to perform topographic survey:
high precision geodetic GPS/GLONASS receiver
3D laser scanner
theodolite
total station
Theodolite - the most cheap option equipment. The cheapest theodolite costs about 25,000 rubles. The most expensive of these devices is a laser scanner. Its price is measured in millions of rubles. Based on this and the prices for topographic surveys, it makes no sense to purchase your own equipment for doing topographic surveys with your own hands. The only option is to rent the equipment. The cost of renting an electronic total station starts from 1000 rubles. in a day. If you have experience in surveying and working with this equipment, then it makes sense to rent an electronic total station and do the survey yourself. Otherwise, having no experience, you will spend quite a lot of time studying complex equipment and work technology, which will lead to significant rental costs that exceed the cost of performing this type of work by an organization with a special license.
For the design of underground utilities on the site, the nature of the relief is important. Incorrect determination of the slope can lead to undesirable consequences when laying sewers. Based on the foregoing, the only possible variant do-it-yourself surveying this is the preparation of a simple plan for a site with existing buildings for simple landscaping. In this case, if the site is on the cadastral register, a cadastral passport with form B6 can help. There are indicated exact dimensions, coordinates and angles of rotation of the boundaries of the site. The most difficult thing when measuring without special equipment is determining the angles. The available information about the boundaries of the site can be used as the basis for constructing a simple plan of your site. A tape measure can serve as a tool for further measurements. It is desirable that its length be sufficient for measuring the diagonals of the section, otherwise, when measuring the lengths of the lines in several steps, errors will accumulate. Measurements with a tape measure to draw up a site plan can be carried out if there are already established boundaries for your site and they are fixed with boundary marks or coincide with the site fence. In this case, to draw any objects on the plan, several measurements of the lengths of lines from boundary marks or corners of the site are performed. The plan is made in in electronic format or on paper. For paper version it is better to use graph paper. The site boundaries are plotted on the plan and used as a basis for further constructions. The distances measured with a tape measure are set aside from the plotted corners of the plot, and at the intersection of the radii of the circles corresponding to the measured distances, the location of the required object is obtained. The plan obtained in this way can be used for simple calculations. For example, calculating the area occupied by a garden, a preliminary calculation of the amount of necessary building materials for additional decorative fences or laying garden paths.
Taking into account all the above, we can conclude:
If topographic survey is required to obtain any official documents (building permit, cadastral registration, town planning plan, planning organization scheme) or designing a residential building, its implementation must be entrusted to an organization that has the appropriate license or is a member of a self-regulatory organization (SRO). In this case, performed do-it-yourself surveying has no legal force and possible mistakes if carried out by a non-professional, can lead to disastrous consequences. The only possible option do-it-yourself surveying it is drawing up a simple plan for solving simple problems on a personal site.
Designation of overhead line supports
Designation of supports.
For supports of overhead lines of 35 kV and above, as a rule, the following notation is used. The number in front letter designation indicates the number of posts that make up the support. If the letter B is present in the designation of the support, this indicates that the support is reinforced concrete, D - wooden, M - multifaceted metal, the absence of these letters means that the support is a metal lattice type. In addition, the designation of the supports includes letters indicating the type of supports (see the table below). The numbers 35, 110, 150, 220, etc., following the letters, indicate the voltage of the overhead line, and the number following them after the hyphen indicates the size of the supports (odd - for single-circuit and even - for double-circuit supports). If the letter T is followed by the standard size of the support, this means that the support has a cable rack. The numbers after the standard size of the support after the hyphen or the “+” sign indicate the size of the additional stand section.
Table - Designation of supports
| Designation | Decryption |
| P | Intermediate support. |
| To | End support. |
| BUT | Anchor support. |
| O | Branch support. |
| FROM | Special support. For example, US110-3 stands for: metal anchor-angle single-circuit special (with horizontal wires) support for 110 kV overhead lines; US110-5 stands for: metal anchor-angle single-circuit special (for urban development - with a reduced base and increased suspension height) support for 110 kV overhead lines. |
| At | Angle support. For example, U110-2 + 14 stands for: metal anchor-angle double-circuit support with a stand 14 m high for 110 kV overhead lines. |
| P | Transition support. For example, PPM110-2 is deciphered as follows: an intermediate metal multifaceted double-circuit transitional support for a 110 kV overhead line. |
| B | Reinforced concrete support. For example, PB110-1T is deciphered as follows: an intermediate single-circuit single-column reinforced concrete support with a cable-resistant for 110 kV overhead lines. |
| M | Multifaceted support. For example, PM220-1 stands for: intermediate metal multifaceted single-circuit support for 220 kV overhead lines. |
| D | Wooden support. For example, UD220-1 stands for: wooden anchor-angle single-circuit support for 220 kV overhead lines. |
| T | Rope-resistant support. For example, U35-2T + 5 stands for: a metal anchor-angle double-chain support with a cable-resistant and a stand 5 m high for a 35 kV overhead line. |
| AT | Support with internal communications. For example, 2PM500-1V is deciphered as follows: an intermediate metal multifaceted single-circuit support with internal connections for a 500 kV overhead line, consisting of two racks. |
