Construction of crane tracks and features of their operation. Methodological recommendations Methodological recommendations for quality control of installation of crane runways Standard height of the handrail above the crane runways

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DEVICE AND CALCULATION OF CRANE ROUTES

1. CONSTRUCTION OF CRANE ROUTES

The design of crane runway elements depends on the installation location of the crane. Most ground erection cranes ride on rails laid on a sleeper base, similar to the superstructure of a railroad track. Cranes installed on building structures of buildings and structures rest on rails mounted on metal or reinforced concrete beams, the shape and dimensions of which are determined by the design and nature of the frame of the building and structure.
The trouble-free operation of cranes depends on the good condition of the crane runway, therefore, regardless of the design, all crane runways must ensure:
strength and stability when exposed to any combination of loads possible under operating conditions;
ease of maintenance and minimal cost of repair work; the possibility of widespread use of standard and standard parts in track construction.
The main document for commissioning crane tracks is the act, the form of which is given on page 183.
In addition, when designing and constructing a crane runway, it should be borne in mind that the work of assembly cranes is temporary, so the crane runways should be assembled and dismantled without significant expenditure of time and money.
Crane tracks on sleeper base
The crane runway on a sleeper base (Fig. 136) consists of the following main elements: rail 1, pads 2, crutches 3, apron butt plates 4, fastening bolts 5, sleepers 6 and ballast prism 7.
Depending on the loads, ordinary railway rails of the types P38, P43 and P50 or special crane rails KR70 and KR100 are used:

Round head main rail
Replacement flat rail in mm width

The rails are laid on flat pads and secured to the sleepers with crutches. The rails are connected to each other with six-bolt railway pads. For the construction of single-rail tracks, block-shaped ones are used.

(from pine or oak) half sleepers with a base width of at least 250 mm and a height h = 50 VP mm (where P is the running wheel pressure in tf).
The trolleys of heavy tower cranes usually move along four-strand tracks, reinforced in the crane parking areas by installing additional rails. Such tracks are laid on sleepers of normal length. The distance between the axles of the sleepers should be taken: for loads on the running wheel up to 28 tf equal to 550 mm, more than 28 tf - 425-450 mm.


Rice. 136. Crane runway on a sleeper base
The strength of rails and sleepers should be checked by calculation.
The sleepers are placed on a crushed stone or crushed stone-gravel ballast layer with a height of at least 250 mm for wheel loads of up to 28 tf and a height of 350-450 mm for heavy loads. The width of the ballast layer (at the top) must exceed the length of the sleepers by at least 150 mm per side.


1 - rail KR100; 2 - channels Nj 24a; S - bolts M16X 65; 4 - sleeper type 1A; 5 - oak beam with a cross section of 300X 300 mm and length / = 350 mm;
6 - grounding of crane rails
Rice. 137. End stop of the crane runway of the K100-31 crane;

Ballast is laid on a well-compacted subgrade, profiled to allow for the drainage of surface water. The latter is achieved through slopes of 0.01 in the transverse direction from the track axis and the installation of ditches located on both sides of the roadbed. The ditches are made with a longitudinal slope of 0.005 and are included in the general site drainage system.
At the end of the crane runway, end stops are installed to prevent the crane from moving beyond the intended track (Fig. 137). The end stops are designed to withstand the impact of the crane moving
with the largest working load and speed reduced by the limit switch, which is installed on the crane's running trolley. Therefore, the trip bars acting on the limit switch must be installed especially carefully and systematically monitored.
In accordance with the Rules of Gosgortekhnadzor, the disconnecting device must act on the electric motor of the movement mechanism of gantry and tower cranes when the crane approaches the stop at a distance no less than the full braking distance of the crane.
Due to the nature of the device, ground tracks for installation cranes require constant care and careful monitoring. The quality of the tracks should be monitored at least 2 times a week, and special attention should be paid to the condition of the ballast layer, checking the rail marks and track width.
Table 14
Tolerances for laying crane rails and maximum permissible deviations during operation


Track irregularities found during inspection that exceed the established tolerances (Table 14) should be immediately eliminated.
When designing and operating ground-based crane tracks on a sleeper base with wheel loads of up to 28 t, you should use the Instructions for the construction, operation and transportation of rail tracks for construction tower cranes (SN78-67), approved by the USSR State Construction Committee on April 13, 1967.
The construction of tracks for heavy assembly cranes with wheel loads of over 28 tf is carried out according to special projects developed in accordance with the drawings of the organization that designed the crane.
Crane tracks on steel and reinforced concrete beams
Crane tracks installed on the building structures of buildings and structures are laid on steel and reinforced concrete crane beams. Steel beams are most often made solid or trussed. Sometimes, with relatively large spans, it is advantageous to use lattice trusses for these purposes.
If several cranes are operating on a crane runway, then when determining the greatest loads acting on the crane beam, it is considered that the cranes are located from each other at the distance of the coupling device.

The construction of large structures is carried out using tower cranes, which are designed to lift and move various loads. For a tower crane, a crane rail track is pre-laid, along which it moves along the structure. Rails (English reils from Latin r?gula - straight stick) are steel beams of a special section that are attached to sleepers (Gol. spalk - support).

High demands are placed on the position of the rail track in plan and height, failure to comply with which can lead to serious consequences: accidents, destruction, accidents, etc. Technical standards for the design and operation of tower cranes are given in official documents (“Instructions for the design, operation and relocation of crane tracks for the construction of tower cranes, SN-78-79.” M.: Stroyizdat, 1979, “Rules for the design and safe operation of load-lifting cranes ." GGTN RF, 1999). Based on these documents, a separate project of geodetic work is drawn up for the period of construction and operation of crane tracks.

To do this, first place the axis of the crane runway on the ground, setting aside from the main axis of the building the distance established for this type of crane, which must be indicated in the working drawing. Half the track width is set aside from the track axis in both directions perpendicularly and the end points of both rails are secured.

Sleepers and rails are laid on a horizontal roadbed, erected according to the vertical layout of the track site, in which the design height of the roadbed is calculated, as well as the volume of excavation work.

To develop a vertical layout project, the following is drawn up: a longitudinal profile along the axis of the track; transverse profiles of the track platform every 5-10 m and at terrain bends; path plan with actual marks of points on its axis and cross-sections.

The cross sections are divided using a theodolite and tape measure. Points on the diameters are secured with stakes level with the ground and their heights are determined by geometric leveling.

When carrying out a vertical layout project, stakes are installed at the points of the cross-sections to the design height and the construction of the subgrade is controlled with a level.

After compacting the subgrade, a layer of gravel (ballast) is poured on top, on which sleepers are laid.

Laying sleepers and fastening rails to them (straightening) is carried out relative to a wire stretched along the axis of the track. The straightening is controlled in height with a level, and the track width (the distance between the inner edges of the rails) is controlled with a tape measure or template.

At the end of the work, an as-built survey of the rail track is carried out by determining, after 10 m, the position of each rail in plan and in a conventional system of heights, the zero of which is the minimum elevation of the rail head. Requirements for the accuracy of laying the crane runway for tower cranes are given below.

Accuracy of laying the crane runway of tower cranes

The specified accuracy of geodetic work is ensured by the use of a theodolite and a technical precision level, as well as a comparable tape measure.

Inadmissible deviations discovered during the as-built survey are eliminated by additional straightening.

If the canvas is erected on soils that are poorly permeable to moisture (clays, loams, etc.), then slopes of the canvas towards drainage are allowed no more than: longitudinal 0.005, transverse 0.01.

In the case of a curved path, a curve of a given radius and cross-sections to it are divided along the axis, points on the cross-sections are leveled, a project for the vertical layout of the track is drawn up, the project is taken to the area and the roadbed is erected. On the finished canvas, a detailed breakdown of the curve is performed for each rail separately. The rest of the work procedure is similar.

During the operation of the tower crane, the condition of the crane runway is systematically checked, as well as after heavy rainfall, after freezing and thawing of the soil.

Research Institute of Organization and Management in Construction (NIIOUS) of the USSR State Construction Committee

Agreed with the chief engineer of the trust
Orgtekhstroy-II Yu.A. Pokrovsky
and with the chief engineer
The first construction and installation trust V.N. Lukin

Moscow 1985

A COMMON PART 1. ORGANIZATION OF GEODETIC LEVELING WORKS. AND CONTROL MEASUREMENTS OF CRANE RAILS 2. CONTROL MEASUREMENTS DURING CONSTRUCTION AND OPERATION OF GROUND CRANE RUNS 3. CONTROL MEASUREMENTS DURING CONSTRUCTION AND OPERATION OF OVERGROUND CRANE RUNS 4. CONTROL MEASUREMENTS DURING INSTALLATION OF SUSPENDED CRANE RAILS 5. GEODETIC CONTROL OF GEOMETRIC PARAMETERS OF CONSTRUCTION LIFTS Appendix Main types of cranes used in construction and their characteristics LITERATURE

Reviewer - First Construction and Installation Trust (Shpakovsky A.V.) Scientific editor - Ph.D., Associate Professor. Sukhov A.N. The recommendations were developed on the instructions of the Orgtekhstroy-II trust and the First Construction and Installation Trust. Based on a generalization of experience, a methodology for performing control measurements of the geometric parameters of crane runways at the stage of their construction and during operation is given. The recommendations are intended for specialists involved in instrumental control and ensuring the accuracy of installation of crane runways. They can also be used when delivering lectures at advanced training courses for engineering and technical workers of construction and installation organizations.

A COMMON PART

Operational safety and normal operating conditions of rail-mounted cranes, durability and reliability of crane structures largely depend on compliance with the design geometry of crane tracks. Monitoring compliance with the design geometric parameters of crane tracks both at the stage of their construction and during operation is carried out as usually by geodetic methods. The quality of the installation of crane tracks and the reliability of determining the actual position of the elements depend on the geodetic measurements carried out to achieve the required accuracy. A specialist monitoring the geometric parameters of the tracks must clearly know the required measurement accuracy, the parameters to be controlled and their limits, deviations from the design ones, measurement methods and instruments that provide the necessary accuracy. Since a large number of lifting cranes are used in construction, differing in design, purpose and method of moving loads, when choosing a particular type of crane, you should be guided by their characteristics given in the appendix.

1. ORGANIZATION OF GEODETIC SIGNING WORKS AND CONTROL MEASUREMENTS OF CRANE RAILS

During the construction of crane tracks, the construction organization (general contractor, subcontractor) must carry out the breakdown of the main axes and remove the markings of the crane tracks from the geodetic base created by the customer [5, 7]. When performing work by a subcontractor, the general contractor is obliged to transfer the geodetic document to it before the start of work breakdown of the main axes and elevations fixed in kind. During the construction process, the general contractor or subcontractor organization (each in accordance with the work performed by them) must carry out geodetic control, which consists of: instrumental verification of the actual position of the structures being built in plan and height; in the executive geodetic recording the actual position of structural elements permanently fixed upon completion of installation; in drawing up and designing an as-built diagram: the planned and altitude position of the crane runway. According to SNiP III-2-75, the responsibilities of general contractors include selective control of work performed by subcontractors in terms of compliance with geometric parameters project. The subcontractor is obliged to provide the general contractor with the necessary materials and information on geodetic work. Executive geodetic survey of the geometric parameters of crane tracks before putting them into operation must be carried out by the geodetic service of the construction organization. During the operation of crane runways, periodic as-built surveys are required to be carried out by line engineers responsible for the safe operation of cranes and other lifting mechanisms operating on crane runways. Line engineer workers engaged in as-built surveys of crane runways must undergo appropriate training and pass exams for the right to perform these works . Persons who have not passed the exams are not allowed to operate crane tracks. The knowledge of linear engineers in the field of geodetic control of crane tracks must be checked by the relevant commission within the established time frame.

2. CONTROL MEASUREMENTS DURING CONSTRUCTION AND OPERATION OF GROUND CRANE RUNS

2.1. When constructing rail tracks, it is recommended to use prefabricated inventory sections with wooden sleepers, wood-metal links and reinforced concrete beams. Their geometric parameters are given in Fig. 1. The characteristics of the sleepers and rails of the crane runway must correspond to the permissible pressure on the running wheels of the crane (see Table 1). To operate tower cranes with eight running wheels and a wheel-to-rail load of up to 30 t, inventory sections with reinforced concrete beams should be used. Rice. 1 Inventory sections of rail tracks: a - with wooden sleepers; b- from wood-metal links; c - with reinforced concrete beams Table 1

Characteristics of sleepers and rails used for the construction of crane tracks, depending on the pressure on the running wheels of the crane

Pressure on the running wheel, tf

Half sleepers

Length, mm

Distance between the axes of the sleepers, mm

Section (l = 12.5 m) with wooden sleepers

From. 23 to 28

Wood-metal section

2.2. During control surveys, the geometric axes of the rails are determined taking into account the geometric parameters given in Table 2. The amount of curvature of the rail in the horizontal plane should not be more than 1/500 of its length. Vertical, horizontal and reduced wear of the rails should not exceed the values ​​​​specified in Table 3 (the reduced wear of the rail head is equal to the sum of the vertical and half of the horizontal wear). The distances between the axes of the sleepers must correspond to the values ​​​​specified in Table 1, and the maximum deviations These distances should be no more than +80 mm. table 2

Geometric parameters of rails taken into account during geodetic surveys

Rail type

Dimensions, mm

Weight of 1 m length (without hole), kg

114

Table 3

Rail head wear limit (mm)

Type of wear

Rail type

Vertical

Horizontal

Given by:

upon acceptance

during operation

2.3. When installing ground-based crane tracks, the geometric parameters indicated in Fig. 2 must be observed. The requirements for the lower structure of the track (subgrade and drainage) during the period of its acceptance into operation are somewhat different from the requirements during operation.

Rice. 2. Structure of the ground crane runway:

A - track size, B - minimum distance from the protruding part of the building, stacks of cargo or other objects, D - width of the surface prism at the top;
1 - ballast prism, 2 - half sleeper, 3 - rails, 4 - building wall, n - side slopes.

During the period of its acceptance, the site for the crane runway must have a single-pitched transverse slope towards the drainage system ranging from: 0.008 to 0.01 (8-10 mm per 1 m) and a longitudinal slope of no more than 0.003 (3 mm per 1 m). The drainage system must have a trapezoidal transverse profile with a depth of 0.35 m and a bottom width of 0.25 m with slopes of 1:1 (for sandy soils 1:1.5). The slope for drainage ditches should be 0.002-0.003 (2-3 mm per 1 m). The requirements for the upper track structure (ballast layer, supporting elements, rails, rail fastenings, etc.) are as follows. Distance from the lower edge of the ballast The prism of the crane runway to the edge of the bottom of the pit must be at least 1.5 times the depth of the pit plus 400 mm for sandy and sandy loam soils and not less than the depth of the pit plus 400 mm for clay soils. The slopes of the sides of the ballast prism must be 1:1.5. It is recommended to install separate ballast prisms with a top width of 1750 mm. The minimum distance from the protruding part of the building to the axis of the adjacent rail, as well as other controlled parameters, depend on the type of crane (see Table 4). Mutual displacement of the ends of the joined rails in plan and height, gaps in the joints of the rails, deviation of the rail track from straightness, the difference in marks of rail heads over a track length of 10 m should not exceed the values ​​​​indicated in the table. 5. The gauge size must be checked along the entire length of the rail track in its middle part and at the joints. Table. 4

Controlled geometric parameters

Crane type

Track size and maximum deviation, mm

Difference in transverse elevations, mm

Minimum radius of a curved section of the track, m

Min. distance from the protruding part of the building to the rail axis, mm

Width of subgrade, mm

Clayey (loamy) soil

when laying

during operation

Dist. between the axles of half sleepers, mm

Ballast thickness, mm

MBSTC-80/100

MSK-8/20(MSK-7.5/20)

KB-100.100.0 grid.

KB-100-0S, KB-100.1

KB-306 (S-981)

MSK-10-20 (MSK-7-25)

KB-160.2, KB-160.4

KB-404 (KS-250)

BCSM-5-10 (T-223)

Table. 5

Maximum deviations of the axes of the crane rails from the design position during installation and during operation (mm)

Controlled parameter

Overhead cranes

Tower cranes

Gantry cranes

Gantry cranes

Bridge material handlers

When laying

during operation

when laying

during operation

when laying

during operation

when laying

during operation

when laying

during operation

Difference in rail head elevations in cross section:

on supports

in flight

Difference in rail marks on adjacent columns (along the length of the rail) at distances between them L

less than 10 m

more than 10 m

1/1000L (but not more than 15 mm)

Distance between axles of crane rails

Mutual displacement of the ends of the joined rails:

in height

Deviation of the rail from a straight line (for overhead cranes a section of 40 m, for tower cranes - 10 m, for the rest - 30 m)

Gaps in rail joints (at a temperature of 0°C and a rail length of 12.5 m)*

Difference in rail head elevations over a track length of 10 m

* For every 100°C temperature change, the tolerance changes by 1.5 mm
Note . Columns 6 and 7 provide values ​​for gantry cranes with a span of up to 30 m. For cranes with a large span, maximum deviations are taken according to the standards for bridge loaders (see columns 10, 11). The maximum deviation from straightness should be no more than 20 mm over a length of 10 m for cranes with a rigid running frame and no more than 25 mm for cranes with balanced running trolleys. The horizontality of the rail heads along the entire path is checked in the middle part of each rail and in the bolt joint area. The longitudinal slope of the path should not be more than 0.003 (3 mm per 1 m), and the transverse slope should not be more than 0.004 (4 mm per 1 m). One link 12.5 m long with transverse and longitudinal slopes of no more than 0.002 (2 mm per 1 m) should be provided for parking the crane during non-working hours.2.4. Before putting a crane runway into operation, its executive geodetic survey is carried out with the obligatory drawing up of an as-built diagram of the horizontal rails and the transverse profile of the track, including its lower and upper structures (Fig. 3). Later, during operation, control surveys of the crane runways are carried out every 20- 24 work shifts with recording of results in the crane shift log [1]. The survey is carried out by foremen or foremen responsible for the operation of the tracks. At the same time, the track size, parallelism of the rails in the horizontal plane, and the amount of elastic subsidence are checked, which is measured when lifting the maximum load on the crane hook and when the angle of rotation of the boom in plan relative to the axis of its path is 45°, without moving the crane. The amount of elastic subsidence of rail tracks under the crane wheels should not exceed 5 mm. Checking the horizontality of the crane track should be carried out at least once a month and after 5-10 days during the period of thawing of the soil, as well as every time after heavy rains.
Rice. 3. Executive diagram of the planned-altitude position of the ground crane track: arrows show the directions of displacement of the rail axis from the design position (deviations of the rail head marks from the horizon are shown in mm); the design horizon level is 160,000; the design gauge is 6000 mm2.5. During the operation of the crane runway, changes occur in the geometric dimensions of its upper and lower structure, which should not exceed the following values: - for a transverse or longitudinal slope of the track 0.01 (1 cm per 1 m); - for mutual displacement of the ends of the joined rails in plan 2 mm and a height of 3 mm; - for elastic subsidence of rail tracks under the crane wheels 5 mm. In addition, the wear of the rail head is checked, which should not exceed the values ​​​​specified in Table 3 for various types of rails, as well as the track size, maximum deviations which for various types of taps are given in table. 4 (gr. 3).2.6. Geodetic measurements of the ground crane track are carried out as follows. Geodetic measurements of the lower structure of the track consist of leveling the site, carried out before the construction of the roadbed, and leveling the roadbed, carried out after its construction. To do this, the surface to be leveled is divided into squares with sides equal to the width of the path. Measurements are performed with N-3 type levels or other equal-precision instruments. Before work begins, the level must be checked and, if necessary, corrected. Readings are taken on two sides (black and red) of a RN-3 type staff with one level installation, or on one side (black) of a staff with two level installations, with a change in its horizon. A benchmark or other “fixed” point, absolute, is taken as the starting point the elevation of which is known in the Baltic height system. It is allowed to accept the mark of the starting point in the conditional height system. The leveling scheme is shown in Fig. 4, and an example of recording the results is given in Table. 6. Table 6

Recording the results of subgrade leveling

Leveling point

Rake readings

excess

The as-built diagram of the lower structure of the track (Fig. 5) shows the dimensions of the roadbed, its transverse and longitudinal slopes, the size of the slopes of the roadbed, the dimensions and slopes of drainage, the profile and dimensions of the roadbed on curved sections. In addition, a diagram of the cross-section of the roadbed is drawn up (Fig. 6). Geodetic measurements of the upper structure of the track include an executive geodetic survey of the plan-elevation position of the track, carried out according to a full and abbreviated diagram, or only a survey of the elevation position.
Rice. 4. Scheme for leveling the canvas (in a conventional height system): □ - grade (H = 100,000 m) Ä - location of level installation
Rice. 5. As-built diagram of the roadbed
Rice. 6. Diagram of a cross-section of the subgrade. An as-built survey of the full diagram is carried out before putting the crane runway into operation. In this case, during the survey, the following parameters are determined: 1) the distance from the protruding parts of a building or structure under construction or existing to the axis of the rail closest to the building or structure (this takes into account the design position of the protruding parts of the building or structure being constructed); 2) the distance from the edge of the ballast prisms (lower) to the edge of the bottom of the pit; 3) cross-section: cross-section, one or two sleepers or half sleepers, their length and the distance between them (their axes), as well as the distance between metal ties; 4) type of rail, vertical, horizontal and reduced wear of rail heads;5) distance between rail joints and gaps in joints;6) gauge size every 6.25 m along the entire length of the crane runway;7) straightness of the crane runway rails;8) marks of the crane runway rail heads every 6.25 m; 9) the amount of elastic subsidence of the rail head. Surveying the track according to an abbreviated scheme is carried out every 20-24 working shifts of the crane. In this case, geometric parameters 6-8 are determined (see list above) and the results are recorded in the crane's shift log. Particular attention should be paid to the condition of the link for parking the tower crane during non-working hours. Leveling of the crane runway (recording only the height position) is carried out at least once a month, and during the period of thawing of the soil - after 5-10 days and each time after heavy rains. Measuring geometric parameters 1-5 does not cause difficulties. The situation with measuring parameters 6-9 is somewhat more complicated. To measure the gauge size and straightness of rails, a theodolite of type 2T5 or 2T2 is used, as well as other theodolites with a reading accuracy of at least 5 "". To do this, at a distance β = 0.5÷1.0 m from the rail axis, at one end of the track, a pin is driven in at point α (Fig. 7) and the theodolite is centered over it. Point the sighting axis of the theodolite pipe at the pin at point α", installed at the same distance from the rail axis at the other end of the track. Then apply the rail sequentially at points 1,2...,n (see Fig. 7) perpendicular to the rail axis in the horizontal plane and take readings along it γ 1, γ 2,..., γ n. Readings are taken along the vertical thread of the theodolite telescope with an accuracy of 1 mm. Next, an angle of 90° is laid off from this direction with the theodolite (alternately at points α and α") and at a distance of approximately 0.5-1 m from the axis of the second rail, pins are driven in at points b and b." In this case, the distances d between points a, b and a", b", must be equal to within 1 mm. Then the theodolite is centered over point b and measurements are taken in the same sequence as at point a. On the as-built diagram, arrows indicate the direction of deviation of the rails from a straight line at the joints and in the middle, and its value ∆ (in mm) is noted above the arrows. If, when counting along the rail, the value γ obtained is less than the distance β (0.5 m), then the direction of the rail displacement is shown inward to the track with a minus sign, and if γ is greater than β, then the rail displacement is shown in the opposite direction with a plus sign. Rice. 7. Scheme for measuring rail straightness and track width. The displacement value is calculated as the difference between the readings on the rail and the distance from the rail axis to the theodolite, i.e. ∆ n = γ n -β n - For example, in our case, for point 2 we will have ∆ 2 = 495-500 = -5 mm, and for point 3 ∆ 3 = 520-500 = +20 mm. Measured track width D n between two displaced points is calculated as the sum of two distances γ 1 and γ n+1 measured by the staff and a constant distance d between directions a-a" and b-b":

D 1 =d+γ 1 +γ n+1

D 2 =d+γ 2 +γ n+2

………………………

D n =d+γ n +γ n+n

where n is the serial number of the point. Taking into account the obtained measurement results, we will have:

D 1 = 5000+495+500 = 5995 mm;

D 2 = 5000+515+495 = 6010 mm, etc.

Calculation control can be performed using the formula

D n =Ш k +∆ n +∆ n+n

where W k is the design gauge. When measuring gaps at rail joints, the temperature of the rails should be taken into account. All dimensions must be adjusted to a temperature of 0°C. For every ±10° deviation of the rail temperature from 0°C, a correction of ±1.5 mm should be introduced into the measurement results. The corrected full-scale measurement of the gap (C) is determined by the formula: C = q+0.15·t°C, where q is the actual gap size obtained during the measurement process; t" is the rail temperature in degrees Celsius at the time of measurements. For example, if measurements were performed at a temperature of +10°C and the gap in the rail joint in plan turned out to be 1 mm, then at 0°C the joint will have a gap of 2.5 mm, i.e. C = 1 + 0.15 10 = 2.5 mm If the measurements were carried out at a temperature of -10 ° C and the gap at the rail joint in plan turned out to be 5 mm, then on the diagram you need to indicate the gap value of 3.5 mm , i.e. C = 5+0.15·(-10) = 3.5 mm. The marks of the rail heads, determined after 6.25 m (at the joints and in the middle with a rail length of 12.5 m), are measured in the same way as leveling the lower structure of the track. On the as-built diagram of the crane runway being put into operation, it is necessary to show the grounding device. This work must be performed by a specialist in the electrical service.

3. CONTROL MEASUREMENTS DURING CONSTRUCTION AND OPERATION OF OVERGROUND CRANE RUNS

3.1. The above-ground rail crane track is made according to design drawings, which indicate the maximum deviations from the design geometric parameters of the track elements. Depending on the lifting capacity of the cranes, different types of rails should be used (see Table 7). Displacement of the longitudinal axis of the crane beam on the supporting surface (platform) columns from the design position should not exceed ±8 mm, and the deviation of the marks of the upper flanges of the crane beams on two adjacent columns along a row and on two columns in one cross section of the span from the design should not exceed ±16 mm (SNiP III-16-80). When installing crane tracks for cranes with a lifting capacity of up to 20 tons, railway rails can be used; for cranes with a larger lifting capacity, special crane rails are used, the characteristics of which are given in Table. 8. Table 7

Main characteristics of overhead cranes, types of rails recommended for them

Load capacity, t

Crane span, m

Crane dimensions of the building, mm

Crane dimensions from the rail head axis, mm

Rail type

1.5 m less than the building span

2 m less than the span of the building

When flying 30-36 m

2.5m less than the building span

With a span of 36 m:

3 m less than the span of the building

With a span of 36 m:

With a span of 36 m:

Fastening of railway rails of type R-38 and R-43 should be done on hooks (Fig. 8), and crane rails of type KR-50 ÷ KR-140 on slats (Fig. 9 and 10). When installing a rail on a reinforced concrete beam, an elastic rubberized tape 8-10 mm thick is laid. The displacement of the axis of the crane rail from the axis of the crane beam should not exceed 20 mm for reinforced concrete beams and 15 mm for metal beams. After the installation of the crane is completed, according to SNiP III-G.10.1.69 (clause 3.5), a geodetic check of the geometry of the crane beams must be carried out tracks, corresponding executive: drawings that are attached to the track acceptance certificate. Table 8

Characteristics of crane rails

Type of crane rails

Main dimensions of rails, mm

Size designation

140

Note: The number in the rail brand means the width of its head (in mm) Rice. 8. Fastening crane rails to hooks: 1 - hooks, 2 - crane rail, 3 - metal crane beam, 4 - spring washer, 5 - nut Rice. 9. Fastening the crane rails to the bars: 1 - bolt, 2 - washer, 3 - bar, 4 - spring washer, 5 - nut, 6 - crane rail, 7 - metal crane beam Rice. 10. Fastening crane rails to reinforced concrete beams on slats: 1 - elastic rubberized tape, 2 - rail, 3 - bolt, 4 - stud, 5 - nut, 6 - washer (plate), 7 - elastic rubberized gasket, 8 - tab, 9 - metal tube, 10 - crane beam, 11 - column 3.2. According to current regulatory documents, when accepting the crane into operation, the geometric parameters given in table should be controlled. 5. When installing crane beams, control the alignment of the geometric axes of their bottom with the axial reference marks marked on the column consoles. The crane beam is installed in the design position by setting aside the design distance from the leader, shifted parallel to the alignment axis, to the longitudinal geometric axis of the top of the crane beam (see Fig. 11). Sometimes, when installing a crane beam in the design position, it is necessary to shift the geometric axis of the bottom of the beam from the geometric axis of the console due to installation errors. This displacement should be no more than 8 mm. In case of large deviations, coordination with the designer's supervision is necessary, which is carried out when drawing up an acceptance certificate for mounted structures. The height of the top of the beams is controlled by measuring the distance to the top of the beam from a mark placed on the inner edge of the top of the column. The magnitude of the deviation from the design of the height position of the top of the crane beam flange is determined as the difference between the values ​​determined in kind and its design elevations. Before installing the crane beams, the height position of the column consoles must be photographed. If the obtained deviations exceed the permissible values, then a constructive decision from the designer's supervision must be obtained to ensure the horizontality of the top of the mounted crane beams. Leveling the top of consoles is common; performed with metal spacers and tables.3.3. When installing crane beams in the design plan-height position, it is necessary to ensure compliance with the following conditions: Rice. 11. Scheme of control measurements and reference marks: 1 - parallel extension from the alignment axis of the columns, 2 - design size from the extension to the geometric axis of the crane beam, 3 - elevation mark, 4 - distance from the mark to the top of the beam, 5 - geometric axis of the beam, 6 - crane beam, 7 - column, 8 - guide line marking the position of the design axis of the crane rail - the distance from the longitudinal axis of the columns to the axis of the crane rollers should be 750 mm for cranes with a lifting capacity of up to 50 tons and 1000 mm for cranes with a larger lifting capacity; - distance from the inner edge of the top of the column to the protruding parts of the end of the bridge crane must be at least 75 mm for cranes with a lifting capacity of 75 tons and above and at least 60 mm for cranes with a lifting capacity of up to 50 tons. The specified distance is measured in such a position of the crane when the average axial planes of the crane the rails and wheels on the corresponding side of the crane coincide. In other positions of the crane, this distance may be less, but in this case, the passage of the installed crane must be ensured with a gap of at least 25 mm; - the permissible approach of the top of the crane to the bottom of the overlying building structure must be at least 100 mm for light, medium and heavy cranes , operating modes and 250 mm for very heavy-duty cranes.3.4. The sequence of geodetic work when installing an overhead crane track is as follows. When installing crane rails in the design position, they are guided by callouts parallel to the alignment axes (see Fig. 11), fixed on the side faces of the columns on the crane beams, and to install the rails in height - on marks of the design position of the crane rail heads on the inner faces of the columns. It is allowed to control the position of the mounted rails in plan using a thread plumb line moved along a string fixed on brackets above the design axis of the rails. After the installation of the rails is completed and they are secured in the design position, an executive survey of their plan-height position is performed. The survey of crane beams is carried out from the alignment axes , fixed, as a rule, with paints on the planes of the columns, using the method of lateral leveling. For this, the theodolite is installed at some distance from the axis of the columns at point 1 (Fig. 12). At the other end of the building, a horizontal staff is installed, combining its zero with the mark that defines the alignment axis, and the theodolite telescope is oriented by pointing at the reading along the staff, equal to the distance of the theodolite from the alignment axis. Then the staff is installed at the ends of each beam, aligning its zero with the geometric axis of the upper part of the beam, and readings are taken from the staff along the vertical thread of the theodolite telescope grid. The readings are recorded on the appropriate diagram. Similar measurements are performed when installing the theodolite at the second point. For control, the distance between the theodolite installation points is measured. Added to the distance from the axis of the columns to the installation points of the theodolite, it should give the span of the building. The height position of the crane beams is determined by geometric leveling. To do this, install the level on one of the crane beams located closer to the middle of the workshop. By installing a leveling rod one at a time on both ends of each beam, they take readings that are recorded in the journal of geodetic measurements. Similar work is carried out when surveying the rails of a crane runway. Based on the measurement materials, an as-built diagram is drawn up (Fig. 13). When surveying overhead crane tracks, it is allowed to install the level not on the beam, but at floor level. In this case, a special T-shaped leveling rod is used for leveling. Installing the level at floor level allows you to carry out measurements in safer conditions than when installing it on crane tracks. Rice. 12. Scheme of measurements during planned as-built survey of crane beams: 1 - theodolite installation locations, 2 - coloring of the alignment axis on the columns, 3 - column, 4 - beam, 5 - geometric axis of the beam, 6 - reading along the rail, 7 - leading line, 8 - staff, 9 - measurement along the staff, 10 - measurement from the axis of the column to the base alignment Rice. 13. Executive diagram of the overhead crane track: arrows show the directions of displacement of the rail axis from the straight line (distances and marks are given in mm); deviations of the rail head from the horizontal are given relative to the design level of 150, 300 m; The cut shows the minimum dimensions

4. CONTROL MEASUREMENTS DURING INSTALLATION OF SUSPENDED CRANE RAILS

Manufacturing, installation and acceptance of suspended tracks are carried out in accordance with the requirements of SNiP III-18-75 and the Rules for the design and safe operation of load-lifting cranes. The maximum deviations in the dimensions of suspended crane tracks during their installation and operation are indicated in table. 9.Table 9

Maximum deviations of the dimensions of suspended tracks from design parameters

Controlled parameter

Manual and electric hoists

Double and multi-hanging cranes

Double and multi-leg suspension cranes with docking locks

during installation

during operation

during installation

during operation

during installation

During operation

Slope of the lower driving belt on adjacent supports along the track

Difference in elevations of the lower running chords of adjacent beams in cross section (mm):

on supports

in flight

Displacement of the beam from the longitudinal alignment axis (mm)

When manufacturing track fastening elements, it is possible to align them in height within 30 mm using an appropriate set of spacers (see Fig. 14) and in plan within 40 mm by moving them relative to the bolts of the hanging table (to allow such movement, oval holes are made in the table) . Based on the indicated values ​​for the possible alignment of overhead track rails when pre-installing them in the design position, the error should not exceed ±15 mm in height and ±20 mm in plan Rice. 14. Fastening of suspended crane tracks and monorails: a - on a hanging table, b - on clamping feet; 1 - truss element, 2 - embedded part, 3 - bolt, 4 - nut, 5 - spacers for alignment, 6 - hanging table with oval holes with a width of d + 40 mm (where d is the diameter of the bolt), 7 - rail, 8 - clamping feet. Before pre-installation of crane tracks, it is necessary to carry out an as-built survey of the height position of the lower chord of trusses and crossbars along the entire length of the track at the places where the rails are attached. If deviations exceed the specified values, an individual design solution should be provided for fastening the tracks to the building structure, agreed with the designer's supervision. Since working conditions at height when installing overhead crane tracks make it difficult to use levels and theodolites, it is allowed to use tensioned wire or nylon fishing line, but to check the horizontality of various levels. As-built surveys of mounted tracks are carried out using geodetic methods, using theodolites, levels and other instruments. Before as-built surveys, it is necessary to check the immobility of the rail fastenings. To do this, test runs of the crane are carried out along the track. If during a test run the crane does not pass along the entire track (the reason for which may be not only a violation of the design geometry of the track, but also a deviation in the dimensions between the driving rollers of the trolley, which compress the lower chord of the beam), then it is necessary to check the dimensions between the rollers. If necessary, they are adjusted by spacers at the points of attachment to the trolley. To record the planned position of the rails, a theodolite is installed on the floor of the building at a distance of 30-50 cm from the axis of the rail. The survey is carried out using the lateral leveling method (see Fig. 15). In this case, a specially designed rail is used or a measuring worker with a leveling staff is raised using a car lift to the level of the tracks (Fig. 16). The height position of the suspended tracks is determined using a level and a specially equipped staff with a plumb line. To do this, the leveling rail is extended with a wooden beam, and the verticality of its installation is controlled by a plumb line. The executive diagram of the suspended tracks is shown in Fig. 17. To survey overhead tracks, you can also use specially made devices in combination with laser devices.

5. GEODETIC CONTROL OF GEOMETRIC PARAMETERS OF CONSTRUCTION LIFTS

When installing and operating lifts, you should be guided by the requirements set out in their technical data sheets. Thus, for lifts PGS 800-50/80, deviations of the guide channels of the mast sections from the vertical are allowed no more than 20 mm along the entire height of the mast. Deviation of the mast of the MGP-1000 lift from the vertical should not exceed more than 0.001 of its height. The deviation of the foundation surface under the supporting part of the lift from the horizon should not exceed 0.001 of its length or width. The geometric dimensions are checked by appropriate measurements once a month or after 200 hours of operation of the lift. In addition, the position of the anchors installed on the building and at the base of the lift and serving to secure it is checked, and the distance from the center of the lift to the wall of the building is checked, which is assigned 2 .66 m or 3.15 m, depending on the project requirements.
Rice. 15. Scheme of geodetic survey of suspended crane tracks using a special rail: 1 - theodolite, 2 - rail, 3 rail
Rice. 16. Scheme of geodetic survey of the planned position of suspended crane tracks using a car lift: 1 - theodolite, 2 - rail, 3 - working, 4 - rail Rice. 17. Executive diagram of the position of the suspended crane track: arrows indicate the direction of displacement (in mm) of the rail from the design position; the numbers next to the arrows indicate the amount of displacement (in mm); Deviations of elevations are shown at extension lines. Before installing a lift, an as-built survey of its base is usually carried out and, based on its results, an as-built diagram is drawn up (Fig. 18). The as-built diagram shows the connection of the faces of the base of the lift to the axes of the building and to the wall closest to the lift, as well as the deviation from the design of the marks of the corners and the center of the base of the platform. In addition, they show the height reference of the lift platform to the zero horizon of the building, the absolute elevation of which must also be indicated on the diagram. After installing the lift and during subsequent checks of its position, an as-built survey is performed, i.e. determine the verticality of its mast in two mutually perpendicular directions and the deviation from the horizon of the base of the lift, Fig. 19. As-built survey of the base of the lift does not cause any particular difficulties. The theodolite is installed at a distance of up to one meter from the wall and the collimation plane of the telescope is oriented along a line parallel to the axis of the building (for example, axis A; see Fig. 18). By placing the leveling rod against the wall, the distance from the alignment to the wall is determined by taking a reading. The distance to the nearest faces of the base of the lift is also determined. Next, turning the telescope 90°, use a tape measure to determine the distance from its collimation plane to the nearest faces of the base of the lift and the axes of the building (in Fig. 18, axes 9 and 10). Then, use a tape measure to measure the overall dimensions of the base. The elevation marks of the base at the support points of the lift are determined by geometric leveling. In this case, it is recommended to determine the actual elevation of the first floor of the building and compare it with the design value.
Rice. 18. Executive diagram of the lift base. Deviations of the top of the lift base from the horizon, the absolute elevation of which is 145.500, and in the building height system +1.000 (dimensions and elevations are given in mm)
Rice. 19. Executive diagram of the verticality of the lift mast and the altitude position of its base (shown in mm are the conventional elevations from the horizon, the absolute elevation of which is 145.50, and in the building height system +1.000)

Application
Main types of cranes used in construction and their characteristics

A tower crane is a jib swinging, load-lifting mechanism that moves along a ground crane track. Main parameters: load capacity from 0.5 to 75 t boom reach up to 40 m lifting height up to 80 m travel speed up to 40 m/min track width from 2.5 to 10 m Bridge crane is a lifting mechanism containing a frame with running wheels. A cargo trolley moves along the frame. The crane's running wheels move along an overhead crane track mounted on crane beams, which rest on column consoles or separate crane racks. Main parameters of the crane: lifting capacity from 1 to 500 tons, span length from 4 to 42 m, speed of movement up to 120 m/min. A gantry crane is a lifting mechanism in which the horizontal span structure rests on supports moving along ground rail tracks. Main parameters: load capacity from 1 to 500 tons, span length from 4 to 32 m, movement speed 20-50 m/min Recently, in the construction of high-rise buildings, they began to use wall-mounted tower cranes, the frame of which is installed motionlessly on a special foundation, and is attached to the latter with anchor bolts. As the height of the building being erected increases, the frame-tower of the crane increases. It is attached with special brackets to the columns of the building frame. This circumstance requires an accurate breakdown of the position of the crane with mandatory reference to the axes and marks of the building being constructed. Careful geodetic control must be carried out both during the construction of the crane tower foundation and when installing the anchor bolts. Otherwise, difficulties may arise when attaching the crane frame to the structures of the building being constructed. In addition to those indicated, there are other types of cranes, but they all usually have ground or above-ground crane tracks, the method of geodetic control of the geometric parameters of which has some differences.

LITERATURE

1. Ganshin V.N., Repalov I.M. Geodetic work during the construction and operation of crane tracks. M.: Nedra, 1980.2. Donskikh I.E. The cross-sectional method for measuring the displacements of structures. M.: Nedra, 1974.3. Instructions for the design, operation and relocation of rail tracks for construction tower cranes. SN 78-79. M.: Stroyizdat, 1980.4. Regulations on the relationship between general contractor organizations and subcontractors./Gosstroy of the USSR and Gosplan of the USSR. M., 1970. 5. Rules for the design and safe operation of load-lifting cranes. M.: Metallurgy, 1981.6. SNiP III-2-75. Geodetic work in construction. M.: Stroyizdat, 1976. 7. SNiP III-G.10.1-69. Lifting and transport equipment. Rules for production and acceptance of work. M.: Stroyizdat, 1970.8. Kruzhitsky I.P., Spelman E.P. Handbook of construction, machinery and equipment. M.: Voenizdat, 1980.

Tower, as well as portal and gantry cranes move along ground crane tracks.

The construction of a crane runway for tower cranes must meet the requirements of the instructions for the design, operation and relocation of crane runways for construction tower cranes SN 78-73, as well as the instructions for the operation of a particular crane for which the crane runway is being constructed.

Each rail track has a lower and upper structure. The lower structure of the track includes the subgrade, elements for strengthening the subgrade and devices for draining water. The subgrade consists of fill soil with appropriate compaction, preferably to natural density. The minimum permissible compaction coefficient should be 0.85 for crane tracks with four running wheels and 0.9 for crane tracks with eight running wheels. The total longitudinal slope of the subgrade site should not exceed 0.005. In draining soils, the subgrade area is allowed to be horizontal.

The superstructure of the track consists of a ballast layer, sleepers, rails and rail fastenings.

The thickness and material of the ballast layer, types of rails, distance between sleepers, track width A and other parameters of the superstructure depend on the type of crane and its characteristics and are determined according to the instructions in the crane passport and instructions for its operation or according to the above-mentioned Instructions SN 78-73.

The best material for constructing a ballast layer is crushed stone or gravel with particle sizes from 25 to 70 mm.

For a track of up to 3 m, the ballast prism is made common to two threads of rails, and above 3 m it can be separate. The slope of the sides of the prism made of sand and granulated slag should be from 1:2 to 1:3, from crushed stone and gravel - 1:1.5.

Rails for crane tracks are used as standard railway ones. The type of rail depends on the load transmitted by the running wheel to the rail. For a load of 20 - 22 tons, R-43 rails are used, for a load of 20 - 25 tons - R-50 rails, and for a load of 25 - 28 tons - R-65 rails.

The rails are joined together using standard rail pads; the gap between the ends of the rails causes dynamic loads when the crane moves, so it is recommended to arrange the rail joint without a gap. The gap in the joints should be no more than 6 mm; The joint should be placed suspended between the sleepers. This joint has greater elasticity and provides better conditions for interaction between the running wheel and the rail. Flat metal pads 12 - 16 mm thick should be installed between the rail and sleepers.

In most cases, the rails are laid on wooden sleepers or half sleepers (Fig. 97, a), the cross sections of which must comply with GOST 78 - 65. The sleepers are attached to the rails using track screws (capcaillie) or crutches.

For faster assembly, disassembly and relocation of crane tracks, inventory links are used. The inventory track link (Fig. 97, a) consists of two sections with rails 1, 12.5 m long, half sleepers 2 and pads 3. The sections are fixed together with ties 4.

Greater stability of the shape of the inventory track link and better transportability are ensured by a design in the form of wood-metal sections (Fig. 97, b), in which the ends of the half sleepers are bordered by longitudinal channels 5, interconnected by ties. 6.

Crane tracks of tower cranes

Recommendations for the design, operation and relocation of crane tracks apply to construction tower cranes with a running wheel load of up to 28 tf. Under specific operating conditions (installation of cranes directly on the structure of buildings and structures under construction, on terrain with karst inclusions, on slopes with a transverse slope of more than 1:10, curved sections, conditions of the Far North when constructing tracks on a snowy base), crane tracks must be built according to an individual project. When the wheel load exceeds 28 tf, the crane runways must be manufactured in accordance with the instructions for the operation of each of such cranes.

The preparation of the area and the installation of crane tracks (Fig. 4.12) for construction tower cranes must be carried out in relation to the chassis and the corresponding pressure on the crane wheel.

The superstructure of the track includes: a ballast layer, supporting elements, rails and rail fastenings, dead-end stops, including rulers and grounding elements. Sleepers for crane tracks should be used in grades 1 and 2 in accordance with GOST 78 - 65 “Wooden sleepers for broad gauge railways.” The fastening of the rails to the sleepers must be carried out using track screws in accordance with GOST 809-71 with clamps or crutches in accordance with GOST 818-41.

Rice. 4.12. Profile of a crane runway on wooden sleepers with a track of 4000 mm:
1 - half sleepers; 2 - rails; 3 - ballast prism; 4 - distance from the axis of the first rail to the protruding part of the building

Rice. 4.13. Plan of a crane runway on wooden sleepers with the location of metal ties:
a - with a resultant pressure on the running wheel from 15 to 22 tf; b - the same, from 22 to 28 tf; A - track size

In addition to the installation of special chocks, it is allowed to install railway chocks in accordance with GOST 12135-66, provided that they are located with a slope inward of the crane runway. For rail joints the following should be used: double-headed rail pads for broad gauge railways in accordance with GOST 4133-54, GOST 19128-73, GOST 8193-73; bolts with hexagonal and reduced heads with guide support according to GOST 11530-65; hex nuts according to GOST 11532-65; spring washers and rail fastenings for broad gauge railways in accordance with GOST 7529-55, GOST 8196-56.

The plan of the crane runway on wooden sleepers with metal ties is shown in Fig. 4.13. Metal ties are attached to the rails and laid along the length of the crane tracks in increments of 6 m. The permissible longitudinal and transverse slopes of the track should be no more than 0.004.