How the power lines are indicated in the diagrams. Types and types of supports of overhead power lines
Depending on the method of hanging the wires, the supports of overhead lines (OHL) are divided into two main groups:
and) intermediate supports, on which the wires are fixed in supporting clamps,
b) anchor type supports, serving 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).
In accordance with the intersection of some engineering structures, for example, public railways, it is necessary to perform on anchor-type supports. At the angles of rotation of the line, corner supports are installed, on which the wires can be suspended in supporting or tension clamps. Thus, the two main groups of supports - intermediate and anchor - are divided into types with a special purpose.
Figure: 1. Scheme of the anchored section of the overhead line
Intermediate straight supports installed on straight sections of the line. On intermediate supports with suspended insulators, the wires are fixed in supporting garlands hanging vertically, on intermediate supports with pin insulators, the wires are fastened with wire binding. In both cases, the intermediate supports perceive horizontal loads from wind pressure on the wires and on the support and vertical loads from the weight of the wires, insulators and the dead weight of the support.
With unbroken wires and cables, the intermediate supports, as a rule, do not perceive the horizontal load from the tension of the 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 take the tension of wires and cables. However, to ensure reliable operation of the line, the intermediate supports must withstand some loads in the direction of the line.
Intermediate corner supports are installed at the angles of rotation of the line with a suspension of wires in supporting garlands. In addition to the loads acting on intermediate straight supports, intermediate and anchor corner supports also perceive loads from the transverse components of the tension of wires and cables.
At angles of rotation of the power line 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 corner supports.
Figure: 2. Intermediate supports of overhead lines
Anchor supports. On lines with suspended insulators, the wires are fixed in the clamps of the tension strings. These garlands are, as it were, a continuation of the wire and transmit its tension to the support. On lines with pin insulators, the wires are fixed on anchor supports with reinforced viscous or special clamps that transfer the full tension of the wire to the support through the pin insulators.
When installing anchor supports on straight sections of the route and hanging wires on both sides of the support with the same stresses, the horizontal longitudinal loads from the wires are balanced and the anchor support works in the same way as the intermediate one, that is, it takes only horizontal transverse and vertical loads.
Figure: 3. Supports of overhead lines of anchor type
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 support will also be affected by a horizontal longitudinal load. 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 wires and cables.
End supports are installed at the ends of the line. From these supports, wires extend, suspended on substation portals. When hanging wires on the line before 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 arrangement of wires on the supports, branch lines - to make branches from the main line, supports large crossings over rivers and water spaces, etc.
The main type of supports on overhead lines is intermediate, the number of which is usually 85 -90% of the total number of supports.
By design, the supports can be divided into free-standing and guyed supports... Guys are usually made of steel cables. Wooden, steel and reinforced concrete poles are used on overhead lines. Structures of supports from aluminum alloys have also been developed.
Overhead line support structures
- 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-post supports are used. Additional structural elements of the support: hanging garland with a hanging clamp, traverse, braces.
- Reinforced concrete supports are single-column, free-standing, without guys or with guys on the ground. The support consists of a stand (trunk) made of centrifuged reinforced concrete, a traverse, a lightning protection cable with a ground electrode on each support (for line lightning protection). With the help of a grounding pin, the cable is connected to the ground electrode (a conductor in the form of a pipe driven into the ground next to the support). The cable serves to protect the lines from direct lightning strikes. Other elements: rack (barrel), pull rod, traverse, cable-resistant.
- Metal (steel) supports (Fig. 5) are used at a voltage of 220 kV and more.
STATE STANDARD OF THE UNION OF SSR
UNIFIED SYSTEM OF TECHNOLOGICAL DOCUMENTATION
SUPPORTS , CLAMPS
AND INSTALLATION DEVICES.
GRAPHIC SYMBOLS
GOST 3.1107-81
( CT SEV 1803 -7 9)
STATE STANDARD OF THE UNION OF SSR
|
Unified system of technological documentation SUPPORTS , CLAMPS Unified system for technological documentation. |
GOST ( CT SEV 1803 -7 9) Instead of |
from 01.07.82
1. This standard establishes graphic designations of supports, clamps and installation devices used in technological documentation. The standard is fully consistent with ST SEV 1803 -7 9. 2. For the representation of the designation of supports, clamps and installation devices, a solid thin line should be used in accordance with GOST 2.303-68. 3. Designations of supports (conventional) are given in table. 1.
Table 1
|
Support and change |
Support Symbol in Views |
||
|
front and back |
|||
| 1. Immovable | |||
| 2. Movable |
|
||
| 3. Floating |
|
||
| 4. Adjustable |
|
||
table 2
|
Clamp name |
Clamp designation in view |
||
|
front, back |
|||
| 1. Single | |||
| 2. Double |
|
|
|
Table a 3
|
Name of the device settings |
Designation of the installation device in the views |
||
|
front, back, top x bottom |
|||
| 1. The center is fixed |
|
No designation |
No designation |
| 2. Center rotating |
|
||
| 3. Center floating |
|
||
| 4. The mandrel is cylindrical |
|
||
| 5. Ball mandrel (roller) |
|
||
| 6. Leader chuck | |||
Table 4
|
Naming the working surface shape |
Designation of the shape of the working surface on all sides |
| 1. Flat |
|
| 2. Spherical |
|
| 3. Tsil indric (ball) | |
| 4. Pr and zmatic | |
| 5. Conical | |
| 6. Rhombic |
|
| 7. Triangular |
Table 5
15. The designation of the types of clamping devices is applied to the left of the designation of the clips (reference annexes 1 and 2). Note. For g and drop 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 recorded to the right of the clamp designation (reference annex 2, pos. 3). 17. On diagrams with several projections, it is allowed on separate projections not to indicate the designations of supports, clamps and mounting devices relative to the product, if their position is uniquely determined on one projection (reference annex 2, item 2). 18. On the diagrams, it is allowed to replace several designations of similar supports on each type with one, with a designation of their number (reference annex 2, item 2). 19. Deviations from the size of the graphic designations indicated in the table are allowed. 1 - 4 and in the drawing.APPENDIX 1
Reference
Examples of marking supports, clamps and mounting devices on diagrams
|
Name van ye |
Examples of application of designations of supports, clamps and fixtures |
| 1. The center is fixed (smooth) |
|
| 2. Center grooved |
|
| 3. Center floating |
|
| 4. Center revolving |
|
| 5. Reverse rotating center with grooved surface |
|
| 6. Leader chuck |
|
| 7. Steady rest |
Types of overhead line supports
In the production of metal structures for power transmission lines the following types of overhead line supports are distinguished:
intermediate supports of power lines,
power line anchor supports ,
corner poles of power lines and special hardware for power transmission lines. Varieties of types of structures of overhead power lines, which are the most numerous on all transmission lines, are intermediate supports that are designed to support wires on straight sections of the route. All high-voltage wires are attached to the traverses of power transmission lines through supporting insulator strings and other structural elements of overhead power lines. In the normal mode, the supports of this type of overhead line perceive the 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 caused by wind pressure on the wires, cables and the very metal structure of the power transmission line. In emergency mode, the structures of intermediate power transmission line supports must withstand the stresses arising from the breakage of one wire or cable.
Distance between two adjacent intermediate supports of overhead lines called an intermediate span. Corner supports of overhead lines can be intermediate and anchor. Intermediate corner elements of power 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 on 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 forces from the tension of wires and cables in adjacent spans, applied at their suspension points along the bisector of the angle of rotation of the power line 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 conditioned by the conditions for the installation of lines, the requirements for the intersections of lines with various objects, natural obstacles, that is, they are used, for example, in mountainous areas, as well as when intermediate corner elements do not provide the required reliability.
Are used anchor corner supports and as terminal, from which the line wires go to the switchgear of the substation or station. On lines passing in a populated area, the number of anchor corner elements of power lines also increases. The overhead lines are attached through the tension strings of insulators. In normal mode, these power transmission towers , in addition to the loads indicated for the intermediate elements of the moldings, the difference in tensions along wires and cables in adjacent spans and the resultant forces of tension along wires and cables act. Usually, all anchor-type supports are installed so that the resultant of the gravity forces is directed along the axis of the support traverse. In emergency mode, the anchor posts of power lines must withstand the break of two wires or cables. Distance between two adjacent anchor supports for power lines called an anchor span. Branch elements of power transmission lines are designed to perform branches from the main overhead lines if it is necessary to supply power to consumers located at some distance from the route. Cross elements are used to cross overhead lines of two directions on them. Overhead line end posts 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 pull of the wires. For overhead lines, anchor supports for power transmission lines are also used, which have increased strength compared to the above types of rack and a more complex structure. For overhead lines with voltages up to 1 kV, reinforced concrete racks are mainly used.
What are the transmission line supports? Classification of varieties
According to the method of fixing in the ground, they are classified:
Overhead line supports installed directly into the ground - Power transmission line supports installed on foundations.Variety of power line supports by design:
Free-standing power transmission line supports - Guy poles
By the number of circuits, power transmission line supports are classified:
Single-circuit - Double-circuit - Multi-circuit
Unified power transmission line supports
Based on many years of practice in the construction, design and operation of overhead lines, the most expedient and economical types and structures of supports for the relevant climatic and geographical regions are determined and their unification is carried out.
Designation of power transmission line supports
For metal and reinforced concrete supports of overhead lines 10 - 330 kV, 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-angle
K, KS - end
B - reinforced concrete
M - Multifaceted
How are overhead line supports marked?
The numbers after the letters in the marking indicate the voltage class. The presence of the letter "t" indicates a two-wire rope stand. A hyphenated figure in the marking of 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, an even number in the numbering is two and multi-circuit. The number through "+" in the numbering means the height of the attachment to the base support (applicable to metal ones).
For example, the symbols for overhead line supports: U110-2 + \u200b\u200b14 - Metal anchor-angle double-chain support with a stand 14 meters PM220-1 - Intermediate metal polyhedral single-chain support U220-2t - Metal anchor-angle double-chain support with two cables PB110-4 - Intermediate reinforced concrete double-chain support
Overhead power lines. Supporting structures.
Supports and foundations for overhead power lines with a voltage of 35-110 kV have a significant share both in terms of material consumption and in terms of value. Suffice it to say that the cost of installed support structures on these overhead lines is, as a rule, 60-70% of the total cost of building overhead power lines. For lines located in industrial plants and in the immediate vicinity of them, this percentage may be even higher.
Overhead line supports are designed to maintain line wires at a certain distance from the ground, ensuring the safety of people and reliable operation of the line.
Supports of overhead power lines are divided into anchor and intermediate. The supports of these two groups differ in the way the wires are suspended.
Anchor supportsfully perceive the tension of wires and cables in spans adjacent to the support, i.e. serve to tension the wires. On these supports, wires are suspended using hanging strings. 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.
The intermediate supports do not perceive the tension of the wires or only partially perceive it. On the intermediate supports, the wires are suspended using supporting insulator strings, Fig. 1.
Figure: 1. Scheme of the anchor span of the overhead line and the span of the intersection with the railway
On the basis of anchor supports, end and transposition supports. Intermediate and anchor supports can be straight and angled.
End anchor poles installed at the line exit 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 line side, since the tension from the substation portal is insignificant.
Intermediate straight 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 support, since it normally does not experience forces along the line. Intermediate supports make up at least 80-90% of the total number of overhead line supports.
Corner supports are set at the pivot points of the line. At angles of rotation of the line up to 20 about, angular supports of the anchor type are used. When the angles of rotation of the power transmission line are more than 20 ° - intermediate corner supports.
On overhead power lines are used special supports of the following types: transpositional - to change the order of the wires on the supports; branching - to perform 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 line circuit the same. In this case, the relative position of the wires in relation to each other is successively changed on the supports. However, this triple movement of the 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.
Figure: 2. Single-circuit line wire transposition cycle
Depending on the number of chains suspended on the supports, the supports can be single-circuit and double-circuit... The wires are located on single-circuit lines horizontally or in a triangle, on double-circuit supports - back tree or hexagon. The most common locations of wires on supports are shown schematically in Fig. 3.
Figure: 3. The most common locations of wires and cables on supports:
a - location at the vertices of the triangle; b - horizontal arrangement; c - arrangement with a reverse tree
The possible location of the lightning protection cables is also indicated there. The arrangement of wires at 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-chain supports, it is more convenient from the point of view of installation to arrange the wires according to the "reverse tree" type, but it increases the weight of the supports and requires suspension of two protective cables.
Wooden supports widely used on overhead power lines up to 110 kV inclusive. The most common are pine supports and somewhat less larch supports. The advantages of these supports are low cost (in the presence of local wood) and ease of manufacture. The main disadvantage is wood decay, especially intense at the point of contact of the support with the soil.
Metal supports are made of steel of special grades for 35 kV and higher lines, they require a large amount of metal. The individual elements are connected by welding or bolting. 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. According to the structural solution of the support body, these supports can be attributed to two main schemes - tower or single-column, fig. 4, and portal, fig. 5.a, by the method of fixing on foundations - to free-standing supports, fig. 4 and 6 and guyed supports, fig. 5.a, b, c.
On metal supports with a height of 50 m and more, ladders with fences must be installed, reaching along the top of the support. At the same time, platforms with fences must be made on each section of the supports.
Figure: 4. Single-circuit line intermediate metal support:
1 - wires; 2 - insulators; 3 - lightning protection cable; 4 - cable-resistant; 5 - support traverse; 6 - support stand; 7 - support foundation
Figure: five. Metal supports:
a) - intermediate single-circuit on guys 500 kV; b) - intermediate V-shaped 1150 kV; c) - intermediate support of a 1500 kV DC overhead line; d) - elements of spatial lattice structures
Figure: 6. Metal free-standing double-chain supports:
a) - intermediate 220 kV; b) - anchor corner 110 kV
Reinforced concrete supports are carried out for lines of all voltages up to 500 kV. To ensure the required concrete density, vibration compaction and centrifugation are used. Vibration compaction is performed by various vibrators. Centrifugation provides very good concrete compaction and requires special machines - centrifuges. On overhead power lines of 110 kV and above, the pillars of the supports and the traverse of the 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 are widespread. They have a lower cost, but have a greater mass and relative fragility of the concrete surface, Fig. 7.
Figure: 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
The 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 typical relief forms are displayed on topographic plans with conventional symbols.
Legend for topography
There are four main types into which conventional signs are divided:
- Explanatory captions.
- Linear symbols.
- Areal (contour).
- Out of scale.
Explanatory captions are used to indicate additional characteristics of the depicted objects: at the river they sign the speed of the current and its direction, at the bridge - the width, length and its carrying capacity, at the roads - the nature of the coverage and the width of the carriageway itself, etc.
Linear conventional signs (designations) are used to display linear objects: power lines, roads, product pipelines (oil, gas), communication lines, etc. The width shown on the topographic plan of linear objects is off-scale.
Contour or area conventional symbols represent those objects that can be displayed in accordance with the map scale and occupying a certain area. The contour is drawn with a thin solid line, dashed or depicted as a dotted line. The formed contour is filled with symbols (meadow vegetation, arboreal, garden, vegetable garden, bushes, etc.).
To display objects that cannot be expressed on a map scale, out-of-scale conventional symbols are used, while the location of such an out-of-scale object is determined by its characteristic point. For example: the center of a geodetic point, the base of a kilometer pole, centers of radio, TV towers, pipes of factories and plants.
In topography, the objects displayed 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 conventional symbols for maps and topographic plans of various scales are created in accordance with this division into objects. Approved by the state. bodies, they are the same for all topographic plans and are required when drawing any topographic surveys (topographic surveys).
Frequently encountered conventional signs on topography:
Points of state geodetic network and points of concentration
- Land use and allotment boundaries with landmarks at turning points
- Buildings. The numbers indicate the number of storeys. Explanatory signatures are given to indicate the fire resistance of the building (w - non-fire-resistant residential (wooden), n - non-residential non-fire-resistant, kn - non-residential stone, kzh - residential stone (usually brick), SMZ and SMN - mixed residential and mixed non-residential - wooden buildings with thin cladding brick or with floors built from 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
- Poles of power lines and communication lines. The legend follows the shape of the column section. Round or square. Reinforced concrete pillars have a dot in the center of the symbol. One arrow in the direction of the electric wires - low-voltage, two - high-voltage (6 kV and above)
- Underground and overhead communications. Underground - dotted line, aboveground - solid. The letters indicate the type of communication. K - sewerage, G - gas, N - oil pipeline, V - water supply, T - heating main. Additional explanations are also given: The number of wires for the cables, the pressure of the gas pipeline, the material of the pipes, 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, Sch - crushed stone, C - cement or concrete slabs. On dirt roads, the material is not indicated, and one of the sides is shown with a dotted line.
- Wells and wells
- Bridges over rivers and streams
- Horizontals. Serve to display the terrain. They are lines formed when the earth's surface is cut by parallel planes at equal intervals of height change.
- Elevations of heights of characteristic points of the terrain Typically in the Baltic height system.
- Various woody vegetation. The predominant tree species, average height of trees, their thickness and distance between trees (density) are indicated
- Free standing trees
- Shrubs
- Various meadow vegetation
- Boggy with reed vegetation
- Fences. Fences are stone and reinforced concrete, wooden, picket fence, netting, etc.
Commonly used abbreviations in topography:
Buildings:
H - Non-residential building.
F - Residential.
KN - Stone non-residential
KZh - Stone residential
PAGE - Under construction
FUND. - Foundation
SMN - Mixed non-residential
SMZ - Mixed Residential
M. - Metallic
development - Ruined (or fallen apart)
gar. - Garage
T. - Toilet
Communication lines:
3 ave. - Three wires on the power line pole
1kab. - One cable per pole
b / pr - without wires
tr. - Transformer
K - Sewerage
Cl. - Storm sewer
T - Heating main
N - Oil pipeline
cab. - Cable
V - Communication lines. Number of cables in numbers, for example 4V - four cables
n.d. - Low pressure
s.d. - Medium pressure
v.d. - High pressure
art. - Steel
cast iron. - Cast iron
bet. - concrete
Areal symbols:
p. pl. - Construction site
og. - Vegetable garden
empty. - Wasteland
Roads:
A - Asphalt
Щ - Crushed stone
C - Cement, concrete slabs
D - Wooden covering. Almost never occurs.
dor. zn. - Road sign
dor. decree. - Road sign
Water objects:
K - Well
well - Well
art well - artesian well
vdkch. - Water pumping station
bass. - Swimming pool
vdhr. - Reservoir
clay. - Clay
Legend may differ on plans of different scales, therefore, to read the topographic plan, you must use the legend for the appropriate scale.
How to correctly read conventional signs on topographic surveys
Let's consider how to correctly understand what we see on topographic surveys using a specific example and how they will help us .
Below is a topographic survey at a scale of 1: 500 of a private house with a land plot and adjacent territory.
In the upper left corner we see an arrow with the help of which it is clear how the topographic survey is oriented towards the north. On a topographic survey, this direction may not be indicated, since by default the plan should be oriented with the top to the north.
The nature of the relief in the surveyed area: the area is flat with a slight decrease to the south. The difference in elevation marks from north to south is approximately 1 meter. The height of the southernmost point is 155.71 meters, and the most northern one is 156.88 meters. To display the relief, elevation marks were used that cover the entire topographic survey area and two contours. The upper one is thin with an elevation of 156.5 meters (not signed on the survey) and thickened to the south with an elevation 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 the grid. They are used to graphically determine the coordinates of any point on the survey.
Next, we will consistently describe what we see from north to south. In the upper part of the topographic plan there are two parallel dotted lines with the inscription "Valentinovskaya St." between them and two letters "A". This means that we see a street called Valentinovskaya, the carriageway of which is covered with asphalt, without a border (since these are dotted lines. Solid lines are drawn with the border, 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:
- A horizontal line runs along it. The relief lowers towards the site.
- In the center of this part of the survey, there is a concrete power line pole, from which cables and wires extend in the directions indicated by the arrows. Voltage of cables 0.4kv. There is also a street light on the pole.
- To the left of the pillar, we see four broad-leaved trees (this can be oak, maple, linden, ash, etc.)
- Below the post, parallel to the road with a branch towards the house, an underground gas pipeline is laid (yellow dotted line with the letter D). Pressure, material and pipe diameter are not indicated on the topographic survey. These characteristics are specified after agreement with the gas industry.
- Two short parallel segments found in this area of \u200b\u200bthe survey are a conventional sign of herbaceous vegetation (forbs)
We pass to the site itself.
The facade of the site is fenced with a metal fence with a height of more than 1 meter with a gate and a wicket. The facade of the left (or right, if you look at the site from the street) is exactly the same. The facade of the right section is fenced with a wooden fence on a stone, concrete or brick foundation.
Vegetation on the site: lawn grass with freestanding pines (4 pcs.) And fruit trees (also 4 pcs.).
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 runs from the gas pipeline route to the house. Underground water supply is connected to the house from the neighboring area. The fencing of the western and southern parts of the site is made of a chain-link mesh, the eastern one is made of a metal fence more than 1 meter high. In the southwestern part of the site, part of the fences of the neighboring areas made of a chain-link mesh and a solid wooden fence are visible.
Buildings on the plot: In the upper (northern) part of the plot there is a residential one-story wooden house. 8 is the house number on Valentinovskaya street. The floor level in the house is 156.55 meters. In the eastern part of the house there is a terrace with a closed wooden porch. In the western part, on the neighboring plot, there is a ruined annex 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 has a canopy on pillars.
Vegetation in neighboring areas: in the area located to the east - woody vegetation, to the west - grassy.
A residential one-story wooden house is visible on the plot located to the south.
This way help to obtain a fairly large amount of information about the territory in which the topographic survey was carried out.
And finally, this is what this topographic survey looks like when applied to an aerial photograph: 
People who do not have a special education in the field of geodesy or cartography may not understand the crosses depicted on maps and topographic plans. What is this conventional sign?
This is the so-called coordinate grid, where integer or exact coordinate values \u200b\u200bintersect. Coordinates used on maps and topoplans can be geographic and rectangular. Geographic coordinates are latitude and longitude, rectangular coordinates are distances from the conventional origin in meters. For example, the state cadastral registration is kept in rectangular coordinates and for each region its own system of rectangular coordinates is used, which differs in the conditional origin in different regions of Russia (for the Moscow region, the coordinate system MSK-50 is adopted). For maps over large areas, geographic coordinates are usually used (latitude and longitude, which you could also see in GPS navigators).
Topographic survey or topographic survey is performed in a rectangular coordinate system and the crosses that we see on such a topographic plan are the intersection points of the circular coordinate values. If there are two topographic surveys of neighboring areas in the same coordinate system, they can be combined according to these crosses and get a topographic survey for two areas at once, according to which you can get more complete information about the adjacent territory.
Distance between crosses on topography
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 was respected when printing or photocopying the source material. This distance should always be 10 centimeters between adjacent crosses. If it differs significantly, but not a whole 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 several times from 10 cm, then most likely such a topographic survey was printed for some tasks that do not require compliance with the original scale. For example: if the distance between crosses on topography 1: 500 scale - 5 cm, which means it was printed at a scale of 1: 1000, distorting all the conventional signs, 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 terrain corresponds to the distance between adjacent crosses on the topographic survey. So for the most commonly used topographic scale 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 by knowing what is between crosses on topography 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 the topographic survey using the crosses (coordinate grid) if the rectangular coordinates of the neighboring crosses are specified. To calculate, you need to multiply the coordinate difference along one of the axes of neighboring crosses by 10. Using the example of the topographic survey given below, in this case, we get: (2246600 - 2246550) * 10 \u003d 500 ---\u003e The scale of this survey is 1: 500 or in one centimeter 5 meters. You can also calculate the scale, if it is not indicated on the topographic survey, using a known distance on the ground. For example, by 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 terrain in meters by the measured distance of this length on the topographic survey in centimeters and multiply by 100. Example: the length of the house wall is 9 meters, this distance measured with a ruler on the topographic survey is 1.8 cm. (9 / 1.8) * 100 \u003d 500. Topographic 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 \u003d 1000)
The use of crosses in topography
The size crosses on topography should be 1cm X 1cm. If the crosses do not correspond to these dimensions, then most likely the distance between them was not observed and the scale of the topographic survey is distorted. As already written, by crosses, in the case of performing topographic surveys in one coordinate system, it is possible to combine topographic surveys of neighboring territories. Designers use crosses in topographic surveys to link the objects under construction. For example, for setting out the axes of buildings, indicate the exact distances along the coordinate axes to the nearest cross, which allows you 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 \u200b\u200bof rectangular coordinates on the crosses.
Topographic survey scale
The scale is the ratio of linear dimensions. This word came to us from the German language, and is translated as "measuring stick".
What is the scale of topographic survey
In geodesy and cartography, the term scale is understood as the ratio of the present value of an object to the size of its image on a map or plan. The scale value is written as a fraction with one in the numerator, and in the denominator - a number indicating how many times the decrease was made.
Using the scale, you can determine which segment on the map corresponds to the distance measured on the ground. For example, moving around a map with a scale of 1: 1000, 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 terrain objects applied to 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, allows you to get plans of a certain size and generalization. For example, a large-scale ground survey can provide a detailed display of the relief and objects on the ground. It is done in the production of land management works, as well as in engineering and geodetic surveys. But it will not be able to show objects over the same large area as 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 the measurements. And all the more experience performers and specialized enterprises performing this shooting should have.
Scale views
There are 3 types of scale:
Named;
Graphic;
Numerical.
Topographic survey scale 1:1000
used in the design of low-rise buildings, in engineering surveys. It is also used to draw up working drawings for various industrial facilities.
Smaller scale 1:2000 suitable, for example, for detailing individual sections of settlements - cities, towns, rural areas. It is also used for projects of rather large industrial structures.
To scale 1:5000 draw up cadastral plans, general plans of cities. It is irreplaceable when designing railways and highways, laying communication networks. It is taken as a basis for drawing up small-scale topographic plans. Smaller scales, starting from 1: 10000, are used for plans of the largest settlements - cities and towns.
But the greatest demand is for topographic surveying at scale 1:500 ... The range of its use is quite wide: from the master plan of the construction site to ground and underground utilities. Larger-scale work is required only in landscape design, where ratios of 1:50, 1: 100 and 1: 200 are necessary for a detailed description of the area - detached trees, shrubs and other similar objects.
For topographic survey at a scale of 1: 500, the average errors of contours and objects should not exceed 0.7 millimeters, no matter how complex the terrain and relief may be. These requirements are determined by the characteristics of the field of application, which includes:
plans of engineering communications;
drawing up very detailed plans for industrial and economic structures;
improvement of the territory adjacent to buildings;
layout of 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.
DIY topography
Is it possible to carry out a topographic survey of your own area with your own hands, without involving a specialist in the field of geodesy? How difficult it is to do topography on your own.
If topography is necessary to obtain any official documents, such as a building permit, granting ownership or lease of a land plot or obtaining technical conditions for connecting to gas, electricity or other communications, you will not be able to provide do-it-yourself topography... In this case, topographic survey is an official document, the basis for further design and only specialists who are licensed to carry out geodetic and cartographic works or are members of a self-regulatory organization (SRO) corresponding to these types of work have the right to perform it.
Execute do-it-yourself topography without special education and work experience is almost impossible. Topographic survey is a rather complex technical product, requiring knowledge in the field of geodesy, cartography and the availability of special expensive equipment. Possible errors in the resulting topographic plan can lead to serious problems. For example, an incorrect determination of the location of a future building due to poor-quality topography can lead to a violation of fire and building codes and, as a consequence, to a possible court decision on the demolition of the building. Topography with gross errors can lead to an incorrect location of the fence, violating the rights of the neighbors of your land plot and, as a result, to its dismantling and significant additional costs for its construction in a new place.
In what cases and how can you do it yourself?
The result of a topographic survey is a detailed plan of the area, which shows the relief and a 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 is the cheapest equipment option. The cheapest theodolite costs about 25,000 rubles. The most expensive of these devices is the laser scanner. Its price is measured in millions of rubles. Based on this and the prices for topographic surveying, it makes no sense to purchase your own equipment for doing topographic surveying with your own hands. The only option is to rent equipment. The cost of renting an electronic total station starts from 1000 rubles. in a day. If you have experience in performing topographic surveys and working with this equipment, then it makes sense to rent an electronic total station and do topography yourself. Otherwise, without 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 that has a special license.
For the design of underground communications on the site, the nature of the relief is important. Incorrect determination of the slope can lead to undesirable consequences when laying the sewer. Based on the above, the only possible option is do-it-yourself topography this is the drawing up of a simple plan for a site with already existing buildings for a simple improvement of the territory. In this case, if the site is on the cadastral register, a cadastral passport with form B6 can help. The exact dimensions, coordinates and angles of rotation of the plot boundaries are indicated there. 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 a basis for building 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 for drawing up a site plan can be carried out if there are already established boundaries of your site and they are fixed with boundary marks or coincide with the fence of the site. In this case, to apply any objects to the plan, several measurements of the lengths of lines from boundary marks or corners of the site are performed. The plan is prepared electronically or on paper. For a paper version, it is better to use graph paper. The boundaries of the site are applied to the plan and used as a basis for further constructions. The distances measured with a tape measure are plotted from the plotted corners of the site and at the intersection of the radii of the circles corresponding to the measured distances, the location of the required object is obtained. The resulting plan can be used for simple calculations. For example, calculating the area occupied by a garden, a preliminary calculation of the amount of required building materials for additional decorative fences or laying garden paths.
Given all of the above, we can conclude:
If topography is required to obtain any official documents (building permit, cadastral registration, urban planning plan, planning organization scheme) or design of a residential building, its implementation must be entrusted to an organization that has an appropriate license or is a member of a self-regulatory organization (SRO). In this case, the performed do-it-yourself topography has no legal force and possible errors when it is carried out by a non-professional can lead to disastrous consequences. The only possible option do-it-yourself topography it is drawing up a simple plan for solving simple tasks on a personal site.
Designation of overhead line supports
Support designation.
For poles of overhead lines 35 kV and above, as a rule, the following designation system is used. The number in front of the letter designation indicates the number of racks 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 is wooden, M is a multifaceted metal, the absence of these letters means that the support is metal lattice type. In addition, the designation of the supports includes letters indicating the type of supports (see table below). The numbers 35, 110, 150, 220, etc., following the letters, indicate the voltage of the overhead line, and the number behind them after the hyphen is the standard size of the supports (odd - for single-circuit and even - for double-circuit supports). If after the standard size of the support there is the letter T, this means that the support has a cable stand. The numbers behind the standard size of the support after the hyphen or "+" sign indicate the size of the additional support section.
Table - Designation of supports
| Designation | Decoding |
| P | Intermediate support. |
| TO | End support. |
| AND | Anchor support. |
| ABOUT | Branch support. |
| FROM | Special support. For example, US110-3 is deciphered as follows: metal anchor-angle single-circuit special (with a horizontal arrangement of 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. |
| Have | Corner support. For example, U110-2 + \u200b\u200b14 stands for a metal anchor-angle double-circuit support with a 14 m high stand for 110 kV overhead lines. |
| P | Transitional support. For example, PPM110-2 stands for an intermediate metal multifaceted transitional double-circuit support for 110 kV overhead lines. |
| 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 cable for 110 kV overhead lines. |
| M | Multifaceted support. For example, PM220-1 stands for an intermediate metal multifaceted single-circuit support for a 220 kV overhead line. |
| D | Wooden support. For example, UD220-1 stands for a wooden anchor-angle single-circuit support for a 220 kV overhead line. |
| T | Support with rope resistant. For example, U35-2T + 5 stands for a metal anchor-angle double-circuit support with a cable-resistant and 5 m high stand for 35 kV overhead lines. |
| IN | Support with internal connections. 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. |
