The importance of engineering surveys for linear objects cannot be overestimated. As a rule, such facilities are subject to state supervision at all stages - from design to commissioning of the structure. Requirements for the quality of construction and installation work are strictly regulated by law. Geodetic work during the construction of linear structures is an integral part of the construction of such objects. GeoGIS LLC is among the leaders in the field of geodesy thanks to the professionalism of its employees and their responsible attitude to business. Our engineers have modern techniques and instruments at their disposal.

Geodetic work during the construction of railways. The main task of the research

A thorough study by our specialists of the strip planned for laying the route allows the Customer to estimate the amount of upcoming labor costs at the pre-design stage.

IMPORTANT! In unfavorable terrain conditions, several alternative options are usually considered to select the least costly one.

Geodetic work during the construction of roads and railway tracks accurately identifies problem areas of the selected route, because its laying often has to be done:

• on hilly areas where the slope exceeds the permissible (in such cases, cutting or adding soil may be required);
• in swampy or flooded areas (the need to improve hydrological conditions, bridge construction);
• in mountainous or hilly areas (laying tunnels, bypass routes).

Geodetic work during the construction of linear structures sequence of execution

The ideal route, which exists only in theory, is a straight line without elevation changes or turns. The reality is that linear objects always have bends and curvature, and often pass through hilly areas. If in the case of laying cable lines and pipelines, the requirements for curvature are not so high, then for transport routes (railroads and highways) there are strict requirements established by regulations for permissible connections and curvature.

IMPORTANT! Geodetic work during the construction of linear structures, which is carried out by surveyors of our company, is designed to ensure optimal placement of the route in the existing conditions of the territory: on the plane and in height.

The route design is its projection onto a horizontal surface and a profile section. The main element of the route is its central axis. It is applied - to the plan (map) during the design process and on site - when transferring the project to nature.

Geodetic work during construction railways and highways are called routing. Our experts include in its composition for transport routes:

1. At the design stage:

• studying the map, choosing the best option placement of the planned object (office tracing);
• calculation of the volume of earthworks (embankments and excavations);
• choice of coordinate system, local reference;
• topographic survey of the strip (it is possible to study several competitive options for subsequent analysis and selection of the best);
• creation of a situational plan of the strip, linear and angular measurements, identification of complex sections (drawing of longitudinal and cross sections, intersections with cable lines, roads).

2. At the construction stage:

• geodetic alignment work during the construction of roads and railways (taking out the red lines of the project, fixing points, points, installing pickets);
• connection to the state network and leveling basis (according to current building standards);
• Executive photography at all stages.

ATTENTION! The width of the strip on which our employees carry out geodetic work during the construction of railways and highways is at least 25 meters from the axis to the right and left (instrumental surveys), by eye - up to 100 meters on both sides of the route.

What are geodetic alignments during the construction of roads and railways?

Geodetic alignment of roads and railway tracks is carried out by employees of our company after approval of the project. To begin work on the construction of a highway, road construction specialists need to have accurate markings on the territory - a project transferred to nature and a complete set of technical documentation. Since highways are much longer than wide, geodetic alignment work during the construction of highways and other linear objects has its own specifics.

Using support points and installing pickets along the designated axis of the structure, our workers carry out:

• marking local network taking into account rotation angles;
• carry out hanging lines and leveling in height;
• provide a link to other linear objects adjacent to the route of the structure.

At the same time, our surveyors are connected to state geodetic networks in compliance with the current SNiP and Russian legislation.

Our specialists carry out geodetic work during the reconstruction of the road. As in the construction process, this allows design solutions to be transferred to the site with great accuracy.

Introduction………………………………………………………………………………. 1 Geodetic work performed during road surveys………………….. 1.1 Laying out the route on the ground. Measuring turning angles and track lines………………………………………………………………………………….. 1.2 Breakdown of picketage, plus points and cross-sections. Shooting of the road strip. Picket magazine…………………………………………………………………… 1.3 Circular curves, their elements and main points. Breakdown of the main points of circular curves……………………………………………………………… 1.4 Transition and total curves……………………………………………………………… 1.5 Calculation of chainage values ​​of the main points of a circular curve. Moving pickets from a tangent to a curve………………………………………………………….. 1.6 Linking the route to the points of the reference geodetic network………………….. 1.7 Leveling the route and cross-sections. leveling………… 1.8 Altitude reference of the route to the benchmarks of the state leveling network. Leveling through rivers and ravines…………………………………………… 4 – length of the curve, distance from its beginning to its end K; 5 – the distance from the top of the rotation angle to the middle of the curve, which is called curve B; 6 – a measure showing how much the path from the beginning to the end of the curve along the tangent is longer than along curve D. The angle of rotation of the route (φ) is measured during tracing, and the value of the curve radius (R) is selected in accordance with technical specifications. The remaining elements of the circular curve can be determined from the right triangle (O – NCC – VUP) in Figure 1.6 using the following formulas: T = R tan φ / 2, K = π R φ0 / 1800, B = R / cosφ / 2 – R, D = 2T – K. Using the above formulas, tables have been compiled in which, using the known φ and R, elements T, K, B and D are found (for example, Vlasov D.I., Loginov V.N. “Tables for laying out curves on railways”). So, for example, for φ = 24030′; R = 400 m; T = 86.85 m; K = 171.04 m; B = 9.32 m; D = 2.65 m. On the ground, the beginning and end of the curve are obtained by plotting the tangent values ​​from the apex of the angle of rotation (VUP) along the lines of the route, and the middle of the curve (MCC) by plotting the value of B along the bisector of the angle (β/2): β/2 = (180º – φº) / 2. This angle is laid out using a theodolite. Point O on the ground is not determined or marked (see Figure 1.6). To facilitate the breakdown of long curves, it is advisable to divide them into several equal parts, called multiple curves. To determine the elements of circular curves for large angles of rotation for any radius value, for example R = 600 m, you can determine from Table 1 the elements for a radius R = 100 m and multiply the found values ​​by radii 600:100 = 6, since the values ​​of T, K , B, D are proportional to the radius of the curve. This can be seen from formulas (1.3). 1.4 Transition and total curves To eliminate a sudden change in the centrifugal force acting on a car when moving from a straight part of the path to a circular curve or vice versa, transition curves are used, the radius of which varies from infinity to the radius of the circular curve. Transitional curves are also inserted between adjacent circular curves of different radii. Clotoids are used as a transition curve on roads (Figure 1.7). clothoids (radial) has where ρ is the variable radius of curvature; transition curve meter; ℓ – length of the transition curve from its beginning to any given point. The size of transition curves on roads is taken to be a standard length multiple of 20 m, depending on the radius of the curve and the category of the road. For roads of category I (with high speeds) transition curves. Figure 1.8 shows a summary curve consisting of a circular curve of radius R and two transition curves. Figure 1.8 – Main elements of the total curve The elements of transition curves are: ℓ – length of the transition curve; р – shift of a circular curve; m – additional tangent. The values ​​of p and m are determined by formulas or selected from tables according to the given radius R and the length of the transition curve ℓ at the bottom of the page of table 1:

Кс = К + ℓ = π R α/1800 + ℓ,

BS = (R + p) / cosα /2 – R,

Ds = 2Ts – Ks.

The radii of the circular curve and the lengths of the transition curves are established by technical specifications. Angle α is measured with a theodolite. These values ​​are initial values. For all other elements of the total curves, tables have been compiled, with the help of which they are broken down on the ground. The layout is similar to the layout of circular curves.

1.5 Calculation of chainage values ​​of the main points of a circular curve.

Moving pickets from a tangent to a curve

To lay out the route, it is necessary to know not only the chainage of the apex of the turning angle, but also the chainage position of the main points of the curve: the beginning of the curve (BCC), the middle of the curve (MCC) and the end of the curve (CCC). To do this, use the following ratios:

NCC = VUP – T, Control:

SKK = NKK + K / 2, KKK = NKK + T – D,

KKK = NKK + K. SKK = VUP – D / 2.

Example. Determine the chainage value of the main points of the curve if the apex of the angle of rotation (AP) is at point PK4 + 28.30, and the elements of the curve:

α = 24030′; R = 400 m; T = 86.85 m; K = 171.04 m; B = 9.32 m; D = 2.65 m

Chainage calculation Control

VUP………………PK4 + 28.30 VUP…………….PK4 + 28.30

T……………… 86.85 + T…………………. 86.65

—————————————- ————————————–

NCC………………PK3 + 41.45 Σ……………..PK5 + 15.15

K………………PK1 + 71.04 – D………………….. 2.65

—————————————- ————————————-

KKK………………PK5 + 12.49 KKK……………PK5 + 12.50

NCC……………….PK3 + 41.45 VUP…………….PK4 + 28.30

K/2………………. 85.42 – D/2…………….. 1.32

—————————————- ————————————-

SKK……………….PK4 + 26.97 SKK……………..PK4 + 26.98

The discrepancy between the two calculated values ​​of SKK and KKK is allowed ± 1 cm. All calculations to determine the position of the main points of the curve are recorded in the picket log.

At the vertices of the turn of the route, all picket and plus points lying on the tangents are placed on the curve. To do this, use the method of rectangular coordinates, the essence of which we will consider using an example (Figure 1.9).

Example. Place picket 4 lying on the tangent on a circular curve with R = 400 m. To do this, calculate the distance K from NCC to PC4:

K = PK4 – PK3 + 41.45 = 400 m – 341.45 m = 58.55 m.

According to tables 5, by interpolation, the values ​​of K – x and ordinates y are found. At K = 58.55 m we get:

(K – x) = 0.20 m; y = 4.27 m.

From picket 4, measure the distance (K – x) = 0.20 m with a tape measure along the tangent towards the NCC, from the resulting point, perpendicular to the tangent, mark the ordinate y = 4.27 m with a tape measure and hammer in a peg, which will determine the position of PC4 on the curve (see Figure 1.9).

Similarly, the remaining pickets and plus points lying on the tangents are taken out.

1.6 Linking the route to points of the reference geodetic network

The alignment of the route to the points of the reference geodetic network is carried out to determine the national coordinates of the points and directional angles of the route lines. The distance along the route between anchored points is determined by technical conditions and can be from 1 to 20 km. The georeferencing results make it possible to determine the planned position of the route on the Earth's surface and have data for reliable control of field measurements. Let's look at some of the most common binding methods.

1 Linking the route to nearby points of the core network

Let there be two points of the reference geodetic network A and B on the ground (Figure 1.10).

In this case, to link point 1 of the route from point A of the reference network, it is necessary to measure the adjacent angle β0 and the distance d0.

Using the known directional angle αAB, the directional angle of line A1 is calculated:

αA1 = αAB + β0.

Then, using the formulas of the direct geodetic problem, the coordinates of point 1 of the route are obtained:

Х1 = ХА + d0 сosαА1,

γ – convergence of meridians.

The convergence of meridians and magnetic declination are usually given in the margins of the map sheet for a given area or determined at the nearest weather stations.

1.7 Leveling the route and cross-sections. Leveling log

Leveling the route is carried out following the breakdown of the picketage, usually in two levels on double-sided slats. The first device is used to level all points along the route: pickets, plus points, benchmarks, main points of the curve. The second tool is used to level only benchmarks, connecting pickets, as well as cross-sections and geological workings on the route. Kilometer-long pickets and benchmarks must be leveled as tie points using both levels. Connecting points are points common to two level positions. All other points on the route are called intermediate.

Leveling the route is carried out by laying a leveling course along the route, consisting of several stations (Figure 1.13).

Leveling along the way is usually carried out using the method from the middle, setting the equality of the shoulders “to”. In this case, depending on the magnification of the telescope, tie points can be taken every 100 or 200 m. In the first case, all pickets will serve as them, and in the second - 50% of them (through a picket). The excesses between the tie and picket points are determined by the black and red sides of the slats, and when working with one-sided slats - by two level horizons.

Terrain conditions (steep slopes, etc.) often force a significant reduction in the distances between connecting points, which is undesirable, since an increase in the number of stations along the course leads to an increase in the amount of work and to a greater accumulation of errors in the total excess.

Let us first consider leveling the route using the method from the middle at a distance of 50 m from the level to the tie points (see Figure 1.13):

h = h1 + h2 + h3 = Σh = Σ(Z – P) = ΣZ – ΣP,

Нпк2 = Нрп1 + Σh.

If there is no second level, then the route is leveled along the broken picketage twice: in the forward and reverse directions. The altitude reference of the route to the benchmarks is carried out by leveling moves from the benchmarks to the points of the route. If terrain conditions allow, it is necessary to select adjacent pickets as connecting points and level all intermediate points between them from one station.

a) at the connecting points, slatters place slats on the top of a peg driven flush with the ground; in accordance with the terrain, the level is installed between the connecting points so that, with the sighting beam in a horizontal position, it is possible to take readings along the rear and front slats, and we must strive to ensure that the distances from the level to the slats are approximately equal;

b) after bringing the vertical axis of the level to a vertical position, point the pipe at the black side of the rear rail, take a reading along the middle horizontal stroke of the grid of threads and write it down in column 3 of the leveling log (Table 1.1).

Table 1.1 – Route leveling log

	Observe washable points	Rake readings	Excesses	exceeding	Horizon level	Absolute (conditional)
	front

End of table 1.1

	Observe washable points	Rake readings	Excesses	exceeding	Horizon level	Absolute (conditional)
	front

Control: (ΣЗ – ΣП)/2 = (18281 – 23633)/2 = 2676, Σhср = ​​– 2676.

For example: hch = Zch – Pch = 343 – 1285 = −1285 mm,

hk = Zk – Pk = 5132 – 6415 = −1283 mm.

The discrepancy between two excess values ​​is allowed no more than 5 mm. If it is acceptable, then the staff is sequentially installed at the positive points, where readings are taken only on the black side of the staff and recorded in column 5 of the journal;

c) if the difference in elevations is more than 5 mm, then re-leveling is carried out at this station.

On terrain with large slopes earth's surface It is often necessary to use plus points or specially installed X-points as connecting points. This may be the case if it is impossible to level two adjacent picket points from one station (Figure 1.14, a).

Figure 1.14 – Application of the X-point

Then one (Figure 1.14, b) or more x-points is selected between the picketing points so that leveling can be done with their help. X-points serve only to convey marks, therefore the distances from them to the pickets are not measured and these points are not applied to the profile.

On curved sections of the route, the beginning, middle and end of the curve, as well as all pickets and plus points placed from the tangent to the curve, are leveled as intermediate points.

Leveling the route through a picket is possible only in flat terrain. The distances from the level to the tie points will be about 100 m. The level in this case is installed at least 10 m away from the route axis. Each picket serves as tie points, and all the rest are leveled as intermediate points.

Leveling the diameters. Crossbars are straight lines perpendicular to the direction of the route. They are usually broken using an ecker or theodolite 20–50 m to the left and right of the route axis. If terrain conditions allow, then the cross-sections are leveled from the nearest longitudinal route leveling stations. IN otherwise cross-sections are leveled from individual stations, and readings on the staff are taken at all points of the cross-section only on the black side of the staff. Readings are recorded on separate pages at the end of the leveling log. A sample entry is shown in Table 1.2.

Leveling stations on cross-sections are selected so that readings are visible at all characteristic points of the cross-section (right and left from its axis), as well as at one or two points lying on the route (usually at the rear or front picket or plus points (Figure 1.15, a) On steep slopes, it is impossible to level the cross-section from one station, so the cross-section is leveled from several stations. In these cases, the heights of the points are transmitted to subsequent leveling stations through tie points lying on the route (Figure 1.15, b).

Table 1.2 – Leveling the diameter

From the station	Observed points	Rake readings	exceeding	Horizon level	Absolute (conditional)
	front

vertical 1:200

Figure 1.20 – Longitudinal profile of the route

The longitudinal profile is composed in the following sequence:

1) draw a profile grid on graph paper. Fill in the columns “Pickets” and “Kilometers”. Every tenth picket is signed with a full number, and the rest - only with the last digit;

2) fill in the columns “Distances”, “Earth marks” and “Ordinates”. In the “Distances” and “Ordinates” columns, draw vertical lines on pickets and plus points, and in the “Distances” column, mark the distances between adjacent ordinates, controlling their sum.

In the column “Ground elevations” write down the heights of points from the leveling log, rounded to 1 cm;

3) paint the vertical line from the conventional horizon line (the top line of the profile grid) and make a profile tattoo according to the ground marks. The distance between the profile line and the conventional horizon line must be at least 6 cm;

4) according to the picket log data, fill in the “Situation” column, where the situation of the road lane is indicated at the axis of the route, plotted as a straight line;

5) in the “Line Plan” column, straight and curved sections of the route and their numerical characteristics are shown. When the road turns to the right symbol the curve is shown in the form of an arc 5 mm upward from the center line, and when turning left - downward. Inside the arcs, the main elements of the curves are written down: φ, R, T, K. and the end of the curve is marked with perpendiculars from the center line to the line of pickets. The distances from the beginning and end of the curve to the nearest pickets are recorded on the perpendiculars. For straight sections, their lengths and directional angles or azimuths are shown. The lengths of straight sections of the route are obtained as the difference between the chainage values ​​of the beginning of the subsequent curve and the end of the previous curve and are recorded above the center line. Directional angles are calculated according to the rule: the next straight line is equal to the directional angle of the previous one plus the right angle of rotation or minus the left one. Their values ​​are written under a straight line;

6) in accordance with the specified technical conditions, when the minimum volume of excavations and embankments and the balance of earthworks are achieved, the design (red) line is drawn through successive samples. The design marks of the design line breaking points are determined graphically. From them, the slopes are calculated with an accuracy of 0.0001 (by dividing the elevations by the horizontal lengths of the lines) and written in the corresponding column of the profile grid. After this, the design elevations of all pickets and plus points are calculated according to the following rule: the design elevation of the next point is equal to the design elevation of the previous one plus the product of the line slope and the horizontal distance between the points;

7) calculate working elevations as the difference between design elevations and ground elevations. Working marks of embankments are written on the profile above the design line, and working marks of excavations are written below the design line;

8) analytically calculate the position of the points of zero work (the points of intersection of the ground line with the design line) using the formula

X = a d / (a ​​+ b) ,

where X is the distance from the point of zero work to the point with working mark a;

a and b – working marks of the nearest pickets or plus points, between which the point of zero work is located;

d – horizontal distance

between working marks.

The profile is drawn and designed in accordance with the sample (see Figure 1.20). The design data is shown in red, the points of zero work and the distances to them are shown in blue, all other design is done in black.

Transverse profiles are drawn up on graph paper in the following scales: horizontal 1:1000, vertical 1:100 (Figure 1.21).

Horizontal distances to the inflection points of the profile on the cross-section are laid to the right and left from the axial point of the route on which the cross-section was laid out. The heights of the cross-section points are plotted vertically from the accepted conventional horizon on the appropriate scale.

1.10 Drawing up a route plan. Sheet of rotation angles,

straight and curved

The route plan is a horizontal projection of the route. A route plan is drawn up on a scale of 1: 5000 or 1: 10000 based on the coordinates of the vertices of the turning angles, and if the route is short, using directional angles (points of reference) and line lengths. The route is painted in red. The position of picket and kilometer points, main points of circular and transition curves are indicated on the route plan. In conventional signs, the situation of terrain strips is depicted. An example of a route plan is shown in Figure 1.22.

Figure 1.22 – Route plan

The “List of turning angles, straight lines and curves” is attached to the route plan (Table 1.3).

ΣP + ΣK = L,

ΣВУП – ΣД = L.

To calculate the initial straight section of the route, take the difference between the chainage of the beginning of the first curve and the beginning of the route. The length of the last straight line is obtained as the difference between the chainage of the end of the route and the end of the last curve. To calculate the distances between the vertices of the turning angles (UPA) in column (13), it is necessary to take the differences between the chainage of the first turning angle and the beginning of the route, each next turning angle and the previous one, the end of the route and the last turning angle. Starting from the segment following the first angle of rotation, it is necessary to add the measure of the previous curve to the resulting differences, since it is set aside on the ground and is not included in the picketage calculation.

Under Table 1.3 all calculations are controlled using the following formulas:

1) the difference between the right and left turning angles must be equal to the difference between the final and initial directional angles of the route lines:

Σβpr – Σβleft = αend – αstart;

2) the sum of all curves plus the sum of all domers should be equal to twice the sum of the tangents with a tolerance of 0.01 - 0.02 m due to rounding errors:

ΣK + ΣD = 2ΣT;

3) the sum of straight sections of the route (ΣП) plus the sum of curved sections

(ΣK) should be equal to the total length of the route (L):

φ = k · 1800/ πR.

Tables have been compiled using these formulas (Table 5, in which the values ​​of the coordinates x and y are calculated using the arguments R and φ. For a joint detailed breakdown of transition and circular curves, the data is taken from Table 4. The breakdown is as follows: along the tangents they are laid down towards the top of the angle of rotation of the length curves k corresponding to the spacing interval, measuring back the values ​​(k – x).At the found points, perpendiculars are restored and the y-ordinates are plotted, thereby determining the points of the curve.

The rectangular coordinate method is the most common method for detailing curves. The advantage of this method is that each point is constructed independently of the previous ones, which eliminates the accumulation of errors. But the rapid increase in ordinate lengths from point to point makes it impossible to use this method in cramped conditions, in tunnels, in wooded areas, along embankments.

In these cases, use method of angles and chords. In this method, the curve is divided at a given interval S along the chord.

When laying out using this method, the chord length S should not exceed the length of the measuring device (usually S = 20 m). Then calculate φ based on the chord (Figure 2.3).

sin φ / 2 = S / 2R. (2.3)

Next, having installed the theodolite at the beginning of the curve, point the telescope in the tangent direction to the top of the rotation angle and set aside the value of the first alignment angle φ/2. The length of the chord S is plotted along the resulting direction, obtaining the first point on the curve. Next, the angle φ is plotted using a theodolite and the position of point 2 is obtained using a linear-angular notch, each time plotting the chord length S from the previous point of the curve.

It should be noted that in this method, the errors in constructing subsequent points contain the errors of the previous ones.

Method of extended chords. Having specified the interval S of the detailed division of the curve of radius R, the angle is calculated using formula (2.3) and, using expressions (2.1) and (2.2), point 1 of the curve is divided using the method of rectangular coordinates (Figure 2.4).

Then, along the continuation of the first chord, S is laid and the resulting point 2′ is fixed. Holding the back end of the tape measure at point 1, determine the position of point 2 by linear notching with radii S and d.

The segment S is plotted again, but from point 2 and along the direction of the second chord. From points 2 and 3′ at the intersection of arcs of radii S and d, the position of point 3 is determined, etc. The value of the segment d, called the intermediate displacement, is constant for all points of the curve and is determined by the formula

The method of extended chords is convenient in that all accompanying measurements are performed in close proximity to the curve. This allows it to be used in cramped conditions, where other methods cannot be used. In addition, the breakdown does not require special tools: it is done using tape measures.

The disadvantage of this method is the rapid accumulation of staking errors as the number of staking points increases.

After the picketing has been restored and the curves have been laid out in detail, the route is secured. Since the axis of the road route is the geodetic basis for laying out all structures, its fastening must be reliable. fastenings are installed outside the excavation zone so that they remain in place for the entire duration of construction.

Simultaneously with fixing the route for ease of maintenance construction work they thicken the network of working benchmarks in such a way that there is one benchmark for 4–5 pickets of the route. In addition, it is necessary to install one benchmark at each small artificial structure and two at medium and large bridges, at the station site and at all embankments and excavations with working elevations of more than 5 m.

As reference points, you can use various local objects that are stable in height and installed below the freezing depth. Benchmarks must be numbered and registered in the benchmarks, indicating their marks, description of the species and location.

2.2 Laying out the subgrade

To carry out excavation work, in addition to restoring the picketing and detailed breakdown of curves, a detailed breakdown of the subgrade or, as they say, breakdown of construction cross-sections is carried out. This breakdown consists of marking on the ground in plan and height all the characteristic points of the transverse profile of the subgrade: axis, edges, bottoms of embankments, ditches, etc.

On straight sections of the route, the cross-sections are divided at intervals of 20–40 m and at all breaks in the longitudinal profile. To do this, using a theodolite and a tape measure, the positive points between the pickets are divided, for example +20, +40, +60, +80 m. The cross-sections themselves are divided to the right and left of these points, perpendicular to the axis of the route.

At curves in the route, the diameter is divided at 10–20 m intervals, depending on the radius of the curve. In these areas, the cross-sections should be located towards the center of the curve, that is, perpendicular to the tangent to the curve at the point where the cross-section is laid out. When dividing the diameters on a curve, they are placed in equal segments. To specify the direction of the cross-section at the axial point of the curve, the angle between the chords connecting this point with two neighboring ones is measured. Then they divide the angle in half and build its bisector on the ground. The direction of the bisector will coincide with the direction of the radius of the curve, along which the cross section is divided from the axial point.

Simultaneously with the breakdown of the cross-sections, the design marks corresponding to the edge mark of the roadway in its finished form are made.

Let us consider the features of the breakdown of diameters in the embankment and in the excavation.

Layout of diameters in the embankment. When laying out cross-sections in an embankment (Figure 2.5) on flat (without transverse slopes) areas of the terrain, fix the position of the projection of the axial point O', the projection of the axial point, the points of the bottom of the embankment K, K1 and the projection of the points of the ditches D, C, E, F. For this from the axis of the route O', using a tape measure, lay down segments B / 2 (B is the width of the embankment at the top) edges and segments h x m to the bottom of points K, K1. Here h is the height of the embankment, 1:m is the steepness (slope) of the slope. The total distances from the axis to the base of the embankment are the same:

O'K1 = O'K = B / 2 + hm.

In sloping areas, laying out the embankment becomes somewhat more complicated. Due to the transverse slope of the terrain by an angle v (Figure 2.6), the distance from the O’ axis to the base of the embankment K and K1 will be different. The position of points K and K1 can be found if the segments O'K and O'K1 are plotted along the inclined terrain. If we denote the angle of repose by β, then by the theorem of sines we will have:

O’K = (B / 2 + hm) sin β / sin (β + v),

О'К1 = (В / 2 + hm) sin β / sin (β + v).

To obtain projections of edges A’ and A’1 on an inclined area, it is necessary to set aside a distance from the axial point O’

O'A' = O'A'1 = (B / 2) / cos v.

Layout of diameters in the recess. When laying out cross-sections in a recess on the ground surface, fix the axial point of the route O’ (Figure 2.7). Segments are laid off from the axial point of the route

O'A' = O'A'1 = B / 2 + D,

The development of automated methods for processing spatial information has led to the emergence of a new direction in modeling - digital modeling. The main elements of digital modeling are: digital elevation model (DEM), digital terrain (DTM), digital object model (DOM).

Coordinate system

In the GLONASS system, frequencies emitted by satellites are also modulated by rangefinder codes and navigation messages. But unlike GPS, the codes of all satellites are the same, and the separation of signals from different satellites is frequency.

To carry out measurements, they are installed on a tripod or on a one and a half meter rod (Figure 4.1), used to perform short-term measurements. The receiver is controlled using the keyboard and display of the controller (Figure 4.2).

Figure 4.1 – Example of sensor installation

The measurement results are recorded on hard memory cards and processed on personal computers using a special software.

4.2.2 Surveying with laser scanners

The ScanStation scanner has a two-axis compensator with a resolution of 1″, the same as in Leica total stations. The scanner can be installed at a point with known coordinates, plot a tacheometric traverse, and determine positions using an inverse geodetic problem. These functions significantly reduce the time of both field and office work, and also make the scanner more versatile for field work.

The Leica ScanStation performs every measurement with the same precision as a total station. The scanner has a very small scanning step and a small laser spot even at long distances. This allows you to achieve optimal control when adjusting data in a project.

Surveying roads is very difficult when carrying out the work itself, since it is not economically profitable to stop everything. Here it is simply impossible to do without the use of a laser scanner. Even if cars are driving non-stop along the road section being photographed and as a result there will be measurements reflected from cars, then when processing in the Cyclone () program, you can simply select one point belonging to the road surface and turn on the function of constructing a smooth surface. Next, the program will automatically select all points that lie on the plane within the limits specified by the parameters for constructing this surface: the maximum distance from the average level, the elevation angle, the greatest distance between two adjacent points and the greatest range of the surface. This function allows, without human intervention, to select only those points that belong to the road and build a three-dimensional map based on them. The Cyclone program also has automatic profiling of filmed roads: the average road surface is automatically built based on several parameters, and profiles are also automatically built over a given distance, including all the necessary reports.

4.2.3 Surveying with integrated systems

To support railway surveying, special complex systems have been developed. These technologies are joint developments of the Swiss companies Leica Geosystems and Amberg Meastechnik. They involve the use of high-tech measuring equipment and a powerful software package.

The LEICA TMS system (Figure 4.4) is used for geodetic support and control of railway track operation processes. The system consists of two main components: LEICA TPS1100plus electronic total stations, LEICA TMS Office software, LEICA TMS SETOUT, LEICA TMS PROFILE.

Figure 4.4 – LEICA TMS system

Automatic measurement of profiles and determination of track geometry is carried out on the basis of measurement technology (Figure 4.5). The use of a radio modem and automatic targeting makes it possible remote control operation of the device from any point. Loading of design data and recording of measurement data can be done using a field computer or a PCMCIA memory card.

Flexibility and versatility of the system.

4.2.4 Surveying using electronic total stations

An electronic total station is a device that combines a range finder, an electronic theodolite and a microcomputer (Figure 4.6). Leading manufacturers of electronic total station systems: Spectra Precision (/Germany), Leica (), Sokkia, Topcon, Nikon, Pentax (), Trimble (USA), UOMZ (Russia).

The light range finder of the device measures the distance to the reflector, which is mounted on a tripod or mounted on a pole that can be moved from point to point for ease of use. The microcomputer provides the ability to solve a number of standard geodetic problems, for which the electronic total station is equipped with a set of necessary application programs. The information obtained during measurements is displayed digitally and is also recorded internal memory device and on flash cards for subsequent input into a computer for further processing.

The electronic tacheometer has controls. The control panel is located on the control panel, which serves to control the measurement process and enter information manually, and a display. Information input and control are also possible from a remote control panel (controller).

The tacheometer may have a light target indicator, which facilitates the installation of a pole with a reflector on the line along which the device is directed. If the reflector is located to the right of the sighting axis, it shines in red, if on the left - green.

Electronic total station software supports solving a fairly wide range of problems. Typically, it is possible to enter and save data about a station: its coordinates, point number, instrument altitude, operator name, date, time, weather information (wind, temperature, pressure).

Based on the measurement results, the horizontal and vertical angles, directional angles of lines, horizontal distances, elevations, heights of points where reflectors are installed, increments of coordinates, flat and spatial coordinates of observed points. It is possible to calculate coordinates based on the results of intersections, calculate the distance to a point that is inaccessible for installing a reflector and the coordinates of an inaccessible point, and determine the height of an inaccessible object. To ensure alignment work, programs are used to calculate the angle and distance for setting out a point with given coordinates. When solving problems, the refraction of light rays in the atmosphere is taken into account.

The use of electronic tacheometers significantly increases labor productivity, simplifies and reduces the time for processing measurement results, eliminates operator errors that occur when visually taking readings, recording measurement results in journals, and in calculations. When working with an electronic total station, there is no need to have a calculator to perform field calculations. Therefore, electronic tacheometers have found the most wide application when surveying railway tracks and highways.

4.2.5 Surveying with combined systems

Editor N. A. Dashkevich

Technical editor V. N. Kucherova

Zach. No. Ed. No. 71.

Publisher and printing

8.1. The role of engineering geodesy in construction

Engineering geodesy is associated with all processes of construction of buildings and structures; all types of geodetic work can be divided into the following stages:

1. Engineering survey:

– hydrological surveys;

– geological surveys;

– geodetic surveys;

– large-scale shooting;

– tracing linear structures

– creating a shooting justification.

Engineering survey– a set of works carried out to obtain information necessary to select an economically feasible and technically sound location for a structure, to resolve basic issues related to the design, construction and operation of structures.

In the process of engineering and geodetic surveys, the situation and relief in the territory of the proposed construction are subject to study and survey,

V resulting in large-scale plans needed for design.

Topographic and geodetic works include:

– construction of a state geodetic network;

– creation of a plan-height survey justification;

– topographic survey;

– construction of large-scale plans for the filmed area. Linear surveys have a number of features and differ in

practical cases of great complexity. Therefore, research in the design and construction of railways and highways, canals, pipelines, power lines, telecommunication lines, etc. allocated separately.

2. Engineering and geodetic design – a set of works carried out to obtain the data necessary to place the structure in plan and height. It includes:

– placement of the construction site by area and height;

– orientation of the main axes of the structure;

– relief design;

– calculating the volume of excavation work;

– performing calculations related to drawing up a design for linear-type structures (including calculation of horizontal and vertical curves, drawing up a longitudinal profile of a future route);

– performing the calculations necessary to transfer the project to

– drawing up layout drawings, diagrams, etc.

Construction of structures is carried out only according to the drawings developed in the project. The project is a complex of technical documents containing a feasibility study, calculations, drawings, explanatory notes and other materials necessary for construction.

The topographic basis for the design is large-scale plans of 1:5000 - 1:500, completed at the survey stage.

Instructions on the composition, accuracy, methods, volumes, timing and order of geodetic work at a construction site are given in the project of construction organizations (POS), project of work performance (PPR) and project of geodetic work (PPGR), which are components general project.

The task of geodetic preparation of the project includes linking together separately located structures on the construction site and ensuring their layout on the ground with a given accuracy. Geodetic calculations in the preparation of projects consist of finding the coordinates and elevations of the points of the structure that determine its position on the ground and the alignment elements for the removal of the structure in plan and height.

The vertical planning project ensures the transformation of the existing topography of the built-up area when placing buildings, structures, underground communications, high-rise solution of squares, streets, intra-block areas and drainage of surface water with minimal movement of earth masses.

The main documents of the vertical planning project are the relief organization plan and the earthwork cartogram, which are compiled on the basis of the topographic plan, working drawings of the transverse profiles of streets and driveways.

The initial basis on which the principles of designing geodetic work on a construction site are developed in practice is the POS (construction organization project) and the PPR (work execution project). Both PIC and PPR contain a geodetic part. This part covers:

– composition, volume, timing and sequence of work to create a alignment and elevation base;

– composition, volume, timing and sequence of survey work for the construction period;

– required accuracy, instruments and methods of performing work.

3. Project for the production of geodetic works (PPGR) contains the following sections:

1. Organization of geodetic work at the construction site.

This section discusses issues of coordinating the scheme for carrying out geodetic work and calendar plans for carrying out measurements carried out by geodetic groups.

2. Basic geodetic work. The section contains diagrams for constructing a planned and high-altitude geodetic basis on a construction site, calculations of the required accuracy of geodetic measurements, diagrams

And methods for constructing a alignment network, types of signs, benchmarks and marks, breakdown of the main and main axes.

3. Scheme of transferring the main and main axes of buildings and structures from the original plan-elevation basis with calculation of the accuracy of the offset and the methodology for performing the work, the layout of axial marks, as well as detailed alignment geodetic work.

4. Geodetic support of the underground part of the structure during the construction of foundations, a method of detailed breakdown for installation of structures, and execution of as-built surveys are being developed.

5. Geodetic support during the construction of the above-ground part of structures. Includes a methodology for creating and calculating the required accuracy of measurements of elements of a planned and high-altitude geodetic basis on the original horizon, selection and justification of methods for transferring axes and elevation marks to installation horizons, as-built surveying.

6. Project for measuring deformations of structures using geodetic methods. They consider the required measurement accuracy, a list of instruments and measurement techniques, the frequency of measurements and methods for processing the results.

4. Marking work

– center networks

– main alignment work

– detailed breakdown of structures by construction stages. Geodetic alignment works are an integral part

construction and installation production. There are planned and high-altitude layouts of structures, which include basic and detailed layout work.

The main alignment work consists of determining on the ground the position of the main axes and the construction field of the engineering structure. They are transferred into nature from the points of the planned and high-altitude geodetic base built in the area of ​​the structure being constructed.

Detailed alignment work consists of determining the planned and altitude position of certain parts of an engineering structure, which define its geometric contours. Detailed alignment work is carried out, as a rule, from the main axes previously transferred to nature

structures by laying out the main and auxiliary axes, as well as characteristic points and contour lines that determine the position of all parts of the structure.

Work related to the breakdown of structures is the opposite of surveying and is characterized by a higher accuracy of their implementation. If an error of 10 cm is made when photographing the outline of a building, then when drawing the outline on a plan at a scale of 1:2000, it is reduced to 0.05 mm, which cannot be expressed on such a scale.

If, when taking the length of a segment from a project drawn up on a scale of 1:2000, an error of 0.1 mm is made (the limit of graphic scale accuracy), then on the ground the size of the error will be expressed as 200 mm, which can often be unacceptable when performing marking work.

Construction tolerances for displacement of axes and deviations from design marks are generally 2–5 mm. Therefore, the dimensions and position of a point on the plan are obtained analytically, and plans of a scale of 1:500 are used to take coordinates.

The layout work includes:

1. Construction of a alignment base in the form of triangulation, polygonometry, trilateration, construction grid, linear-angular constructions. The geodetic alignment base is used to build an external alignment network and perform as-built surveys.

2. Setting out the main or main axes of buildings (creating an external alignment base) and design elevations. The external alignment base is the basis for performing detailed alignment work.

3. Detailed alignment work at the stage of excavation of the pit, laying out communications, installation of foundations, transfer of marks and axes to the bottom of the pit, construction of the above-ground part of the building.

The main elements of marking work are setting out the design angle, design distance, design slope and design elevation.

Depending on the type of structure, measurement conditions and requirements

To accuracy of its construction, alignment work can be carried out using polar or rectangular coordinates, angular, linear or alignment serifs and other methods.

5. Alignment of structures and technological equipment

- in respect of;

– in height;

- vertically.

The most important geodetic characteristics to be determined are straightness, horizontality, verticality, parallelism, inclination, etc. The combination of these characteristics makes it possible to determine the plan and elevation position of various elements.

As construction progresses, a set of geodetic works, called as-built survey, is performed to determine the planned and altitude position of individual elements. The accuracy adopted during the as-built survey must be no lower than the accuracy of the alignment work.

6. Observation of deformations of buildings and structures

– subsidence of bases and foundations

– horizontal offset

– tilting of tower-type structures.

Deformation of structures call a change in the relative position of the entire structure or its individual parts associated with spatial movement or change in its shape.

Deformations of structures manifest themselves in the form of deflections, torsion, roll, shear, distortions, etc. In general, the deformation of structures can be reduced to the two simplest displacements of the structure - shear in the horizontal plane and settlement in the vertical plane.

Deformations of structures arise due to uneven settlement of the structure caused by soil shrinkage, as well as insufficient strength of structures. For timely prevention of accidents and for a more detailed study of the reasons for the violation of the operational qualities of structures, systematic observations of deformations of their structures are carried out. For this purpose, special sedimentary marks are laid in the construction of structures and their marks are periodically determined using high-precision geodetic methods.

In the process of engineering activities in construction, surveyors are guided by regulatory documents, in particular:

	Document	Document's name
	SNiP 11–02–96	Engineering surveys for construction. Basic
		provisions
	SP 11–104–97 Part I
		government
		Engineering and geodetic surveys for construction
	SP 11–104–97 Part II	government Surveying underground utilities
		cation during engineering and geodetic surveys for
		construction
		Engineering and geodetic surveys for construction
	SP 11–104–97 Part III	government Engineering and hydrographic work for
		engineering and geodetic surveys for construction
		government
		Engineering and geodetic surveys of iron and
		highways
		Executive geodetic documentation. Pra-
		TO a load weighing up to 10 kg is hung on a tape measure and lowered into a bucket With water to reduce its swinging. Observations are carried out with equal arms from the device to the staff and tape measure. As a result of measurements, corrections are introduced for compar- tapholes, stretching and temperature. Tension correction from suspension where P is the weight of the load; L – tape measure length L=c-b; E – elastic modulus (for steel E=20*10 7 Pa); s is the cross-sectional area of ​​the tape measure. The temperature correction is determined from the expression: ∆t=α(t-t0 )L, (7.4) where α is the coefficient of thermal expansion of the tape measure (for steel α = 0.0000125); t – tape measure temperature; t 0 – tape measure comparison temperature; L – tape measure length L=c-b. 7.12. Geodetic alignment work during the construction of highways and linear structures The purpose of the alignment work is to transfer to the area all the elements of the construction site. highway, bridge crossing and their structures in full accordance with the design data. Those- The technology of marking work must ensure the specified accuracy, reliability, ease of execution and maximum performance ness of labor. Marking work during the construction and reconstruction of roads and artificial structures is carried out in the following sequence: preparatory work; restoration of the route and axes of structures; creation of construction support networks and transfer of the main axes of the designed engineering structures to the area; detail- nal marking works; geodetic management of construction work body machines; geodetic control of work; executor- surveys and acceptance of engineering structures in operation. All main elements of the roadbed, artificial structures (bridges, viaducts, overpasses) are subject to detailed breakdown dovs, tunnels) and their scaffolding, temporary overpasses and avanbeks, regu- lation and bank protection structures, drainage systems weapons (mountain ditches, differences in fast currents, water trenches boats, straightened riverbeds, etc.); bases and coatings, road pavement, turns and their bends and widenings on curves, exits and crossings sections, bus stops, sites for car pavilions, buildings of operational and motor transport services, asphalt and pulp and paper plants (removal of their vertical planning projects and building projects to the area, structures and services), special engineering structures (sub- pore walls, banquets, barrages, anti-mudflow and anti-mudflow structures avalanche protection, balconies, galleries and half-tunnels), routes under- connected lines of electricity, water and heat supply, sewerage, gas zification, telephone, drainage network. 7.12.1. Fastening the route, axes and support networks of engineering structures Planned position of points and lines of reconstructed routes, axes of bridge crossings, approaches to them and points of support networks of all artificial structures, the table is securely fixed to the ground bams or wooden stakes with appropriate markings of all securing marks. The turning angles of the route are fixed with four signs: in ver- the corner tire (at the site where the theodolite is installed) is hammered with a secret stake - The neck is level with the surface of the earth and a ditch is rolled out around it, 10–15 cm deep, with a radius of 0.7 m (Fig. 7.15). At a distance of 2 m in the direction of the outer bisector of the corner, a corner support is buried. knowledge pillar. On the continuation of the sides of the angle, outside the pre- standing excavation work, they are burying two more identification tables - ba (Fig. 7.16). The apex of the rotation angle is tied to two or three standing objects of the area. Rice. 7.15. View of the design of a secret peg at the corner of the route Rice. 7.16. Scheme for fixing the angle of rotation of the route It is allowed to fix the turning angles using four pivot posts (Fig. 7.17). In this case, every two pillars are placed on the continuation of the sides of the corner outside the excavation. If the top at the angle of rotation of the route is located outside the construction area bot, then it is secured with a bulk cone of earth 0.5 m high and dia. meter 1.3 m (Fig. 7.18). The stake at the top of the corner is driven flush with the ground, a groove 10-15 cm deep with a radius is dug around it 0.7-0.8 m. At a distance of 15-20 cm from the stake, a guard with a mark is placed by indicating the rotation angle number and its chainage position. Rice. 7.17. Scheme for securing a turn with pivoting pillars Rice. 7.18. Scheme for fixing the rotation angle located outside the construction work Points of support networks of artificial structures, bridge axes transitions and approaches to them are secured with axial and angular (identification) pillars. Pickets and positive points of the route, the beginning and end of each curve the howl is secured with pegs with guards (Fig. 7.19). Gatehouses for hit in front of the pegs along the route. Rice. 7.19. Type of design of pickets, plus points, main points of the curve All main points of the route are assigned to the work area according to the pepperpots with remote stakes. The signs establish a perpendicular parallel to the highway behind the edge of the ditch of the existing road. In the mountain, in hilly and taiga areas such outrigger poles (stakes) are installed They are placed near the boundaries of the allotment along the alignment of cross-sections at least every 100 m. When installing outrigger posts and stakes in one direction, the distance between the target posts of each cross-section should be at least 20 m (Fig. 7. 20) between stakes 10 m. Benchmarks when fixing highway routes are installed There are two types of pours: permanent and temporary. As permanent reference points, time-unshakable points embedded in the center are used. Rice. 7.22. Photo of the GDN ground benchmark (installed by the GiproDorNII Institute) Rice. 7.23. Design of the main ground benchmark GDN (installed by the GiproDorNII Institute) Rice. 7.24. Photo of a benchmark located on the closet wall Rice. 7.25. Photo of a state ground marker installed in a mountainous area For high-altitude reference of routes, bridges and road structures, I use permanent wall benchmarks a and marks b (Fig. 7.26-7.27). The position of the signs for fixing such leveling points is described in detail in the project, attaching a sketch drawing of the building and indicating knowledge of the planned and altitude location of the sign relative to the base and corners of the building. Wall benchmarks and marks secure the leveling lines 2024 bkpc.ru. About LEDs - Connection. Use in cars. Installation. Kinds.