Ensuring safety when using lifts
Occupational safety at urban construction and economy when using cranes and hoists.
Educational-methodical, practical and reference manual.
Authors: Roitman V.M., Umnyakova N.P., Chernysheva O.I.
Moscow 2005
1. OCCUPATIONAL HAZARDS WHEN USING CRANES AND LIFTS.
1.1. The concept of industrial hazard.
1.2. Dangerous zones at the construction site.
1.3. Examples of characteristic accidents and accidents associated with the use of cranes and hoists.
1.4. The main causes of accidents and accidents when using cranes and hoists.
2. GENERAL ISSUES OF LABOR SAFETY WHEN USING CRANES AND LIFTS.
2.1. General condition for ensuring labor safety.
2.2. Regulatory bases for ensuring labor safety when using cranes and hoists.
2.3. The main tasks of ensuring labor safety when using cranes and hoists.
3. ENSURING WORK SAFETY WHEN USING CRANES AND LIFTS.
3.1. Selection of cranes and their safe binding.
3.1.1. Crane selection.
3.1.2. Cross-tie of cranes.
3.1.3. Longitudinal binding of tower cranes.
3.2. Determination of the boundaries of hazardous areas of operation of cranes and hoists.
3.3. Ensuring labor safety in hazardous areas of operation of cranes and hoists.
3.3.1. Instruments and safety devices installed on cranes.
3.3.2. Ensuring safety when installing cranes.
3.3.3. Protective grounding of crane runways.
3.3.4. Ensuring safety in the joint operation of cranes.
3.4. Measures to limit the dangerous zone of the crane.
3.4.1. General provisions.
3.4.2. Forced restriction of the crane operation area.
3.4.3. Special measures to limit the danger zone of the crane.
3.5. Ensuring labor safety when installing cranes near power lines.
3.6. Ensuring labor safety when installing cranes near recesses.
3.7. Ensuring safety in the storage of materials, structures, products and equipment.
3.8. Ensuring safety during loading and unloading operations.
4. SOLUTIONS TO ENSURE LABOR SAFETY IN ORGANIZATIONAL AND TECHNOLOGICAL DOCUMENTATION (PPR, POS, etc.) WHEN USING CRANES AND LIFTS.
4.1 General provisions.
4.2. Stroygenplan.
4.3. Technological schemes.
3.3.5. Ensuring safety when using lifts.
To lift workers to their workplaces during the construction of buildings and structures with a height of 25 m or more, it is necessary to use passenger-and-freight lifts.
The lifting capacity of the lift is determined by its passport.
Installation and operation of lifts should be carried out in accordance with the requirements of the instructions for installation and operation of manufacturers or specialized organizations, relevant standards, guidelines, recommendations.
Before installing the lift, plan the site and concrete the slab with the installation of anchor bolts along the conductor or support frame.
The lift is attached to the building according to an individual project. The lift must be grounded.
Rise to the roof to produce after dismantling the tower cranes. The head of the lift during the operation of the cranes must be at least 0.5 m below the mounting horizon.
An alarm must be connected to the lift control point from all floors.
The presence of people in the danger zone from the action of the lift (Fig.3.5, 3.6) is prohibited.
During non-working hours, the lift cabin must be in the lower position.
On the floors opposite the stop of the lift cabin, it is necessary to install doors to the height of the opening (h=1.8m) and a width of 1.2m. Doors must have special locks, closed from the outside of the building. On the floors and the roof, for unloading materials and exiting people from the lift, it is necessary to arrange a platform with an opening width and a length of 1 m with a ramp, the slope angle should not exceed 300. The platform and ramp should have a railing.
A protective canopy 1.0 x 1.5 m from boards 40 mm thick is installed above the minder's workplace, which is outside the danger zone.
Two-way visual communication (or an alarm) must be established between the minder and the worker who accepts the goods.
At the lift at the loading point, a stand must be installed, which shows the lifting capacity of the lift, a table of masses of goods with a list and quantity of goods and methods of packing, a list of responsible persons and rules for using the lift.
Post warning signs along the danger zone. The presence of people in the danger zone of the lift during the lifting of goods is prohibited. It is also forbidden to work on a faulty lift and go to the cargo area.
The site where the lift is installed must be horizontal, the foundation cavities must be backfilled and compacted in accordance with the requirements of building codes and regulations to the density of the soil according to the project. A monolithic reinforced concrete slab must be made under the base frame of the lift, or prefabricated reinforced concrete road slabs or a special slab must be laid in accordance with the requirements of the manufacturer's installation and operation instructions. On fig. 3.17 shows an example of the design of a monolithic reinforced concrete slab for the installation of a passenger-and-freight lift MGP-1000V.
The construction hoist is fastened to the building frame structures after all the building frame components have been completed in accordance with the detailed design.
The lift is attached to the building according to the project developed for this building, provided:
- the strength of the monolithic structures of the building frame and its components by the beginning of the operation of the lift must be at least 70% of the design strength; the possibility of operating the lift with a lower concrete strength of the monolithic structures of the building and its components is agreed with the design organization - the author of the building project;
- the possibility of attaching the lift to the structures of the building and the attachment points must be agreed with the design organization developing the project for this building (or developing the project for its reconstruction). If necessary, the design institute develops a project to ensure the stability of the building from the effects of loads created by the lift.
At the entrance to the cabin of the passenger-and-freight lift at the first stop (on the surface of the earth), a ramp and a protective visor are arranged, similar to the visor of the entrance to the building.
The openings at which the cabin of the cargo-passenger lift or the platform of the cargo lift stops must be closed with doors with special locks installed for the passenger lift on the outside of the door, and for the cargo lift on the inside.
The doors in the openings of the building are opened (closed) with a passenger-and-freight hoist by the driver, and with a cargo hoist, by the workers responsible for receiving goods on the floors. Opening doors, regardless of the type of lift and installation conditions, must always open to the inside of the room.
During the construction of buildings with balconies (loggias), it is necessary to install lifts at these balconies in order to use balcony doors to enter the building. At the same time, it is prohibited to store goods on the platforms of balconies (loggias).
When installing a lift near a balcony or loggia, you need to use a balcony door, installing a latch or a bolt lock on it from the outside. Enclose the passage from the lift to the balcony door on both sides with a fence 1.2 m high from the level of the platform floor to the lowest point of the upper horizontal element in accordance with GOST 12.4.059-89.
Doors 1800 mm high and at least 1200 mm wide should be installed opposite the stop of the cargo-passenger lift cabin so that the retractable platform or lift ladder can enter the opening.
If the height of the opening is less than 1800 mm, it is necessary to ensure a safe entrance to the opening (arrange inclined canopies on both sides of the opening; the canopy from the cabin side does not reach it by 350 mm; upholster the canopies and the top of the opening with soft material, install warning signs, paint the canopies in signal colors, carry out additional instructions).
Wall of an existing building
Fig.3.17. An example of a monolithic reinforced concrete slab for the installation of a passenger-and-freight hoist MGP-1000V
Carrying out loading and unloading operations with an opening height of less than 1400 mm is prohibited.
In case of installation of a lift near a building in which there are no floor-by-floor enclosing structures (including a parapet on the roof), on both sides of the installed doors along the facade of the building, at least 2 m in each direction, a solid fence is arranged along the ceiling to a height of 1.6 m, meeting the requirements of GOST 12.4.059-89.
To exit people from the lift cabin and unload materials into window openings at the level of the lower part of the window opening, a receiving platform is arranged for the width of the opening and a length of at least 1 m with a ramp, the slope of which should not be more than 300 (Fig. 3.18).
The receiving platform and the ramp are carried out in accordance with the project of a specialized organization. Similarly, they arrange a platform with a ramp through the parapet at the exit to the roof. It is forbidden to go out onto the loading platform of the construction hoist.
An alarm must be connected to the place of control of the cargo-passenger lift from all floors, or the lift must be equipped with telephone or radio communication with each floor (with each receiving platform). The communication line must be independent of the lift power supply.
In the building, next to the openings on the outer and inner sides of the walls or fences, numbers corresponding to the floor numbers should be applied.
The cargo lift control device must be installed in a place with sufficient visibility of the loading and unloading areas and outside the danger zone from the building under construction and the lift. Installation locations are determined in the PPR. During non-working hours, the switch and the power supply cabinet of the lift must be de-energized and locked.
It is not allowed to load the lift with a concentrated load, the mass of which exceeds 200 kg.
To supervise the safe operation of lifts, the owner of the lift must appoint a specialist to supervise the safe operation of the lift.
Responsibility for the maintenance of lifts in good condition, the owner must assign to the specialist, who is subordinate to the personnel serving the lift.
In each workshop, at a construction site or other area of work of lifts in each shift, a person responsible for the safe performance of work by lifts from among the foremen, superintendents, site supervisors, as well as foremen, certified in accordance with Section 10 of the Rules for the Arrangement and safe operation of elevators”, approved on January 26, 1971.
For the operation of lifts, the following must be appointed: by order of the construction and installation organization, persons responsible for the operation of the electrical facilities at the construction site, persons engaged in the acceptance of cargo on the floors, the minder of the cargo lift, as well as slingers on the lift with a cantilever boom, by order of the organization of the owner of the cargo-passenger lift - drivers.
Rice. 3.18. Binding of remote platforms for receiving goods.
a- protruding part of the site; in- the width of the site; With- the width of the main deck; d, d1– site binding dimensions;l– the size between the sites is not less than 1m.
Persons who have been trained and have the appropriate certificate for the right to operate this type of lift are allowed to operate the lift.
It is forbidden to transfer control of the lift to other persons or work on a malfunctioning lift.
For all loads lifted by the lift, a table of masses of loads is compiled, which is handed over to the conductor-driver, the workers performing the loading, and hung out at the places of loading and unloading of the lift. The table indicates the mass of a unit of cargo, methods of packing, the maximum number of cargoes and their total maximum weight allowed for lifting or lowering (Table 3.2)
Table 3.2.
The form of the table of masses of goods supplied to the remote platform.
When determining the maximum mass of cargo moved by a passenger-and-freight hoist, it must be taken into account that there must be a driver-conductor in the cab, so the value of the maximum mass of cargo must be less than the lifting capacity of the hoist by 100 kg. The form of the table of masses of goods moved with the help of a lift is given in table 3.3.
Table 3.3.
The form of the table of masses of goods moved with the help of a lift.
| No. p / p | Name of goods | brand, size | Unit rev. | Packing method | Qty. units per lift, pcs. | Mass of a unit of cargo, kg | Total weight per lift, kg |
| 1 | Solution | M-50 | PCS. | Stretcher | 5 | 60 | 300 |
| 2 | Ruberoid | RB | PCS. | Roll | 10 | 40 | 400 |
| 3 | Mastic | B-1U | PCS. | flask | 6 | 60 | 360 |
| 4 | Metlakh tile | 150x150 | PCS. | Box | 20 | 20 | 400 |
| 5 | Brick | M-75 | PCS. | Cart T-200 | 1 | 200 | 200 |
For cargo lifts with a cantilever boom, as part of the PPR, cargo slinging schemes with a table of masses of cargo and used load gripping devices should be developed.
The danger zone boundary for lifts is determined according to Section 3.2 and Figures 3.5 and 3.6.
The signal fence, exposed along the contour of the danger zone of the lifts, must meet the requirements of GOST 23407-78.
Access roads, cargo storage areas and a canopy (size 1.0 1.5 m) for a minder (for a cargo lift) must be located outside the danger zone.
The approach of the lift, its cabin or the platform of the cargo lift to the building or its protruding parts is determined by the operational documentation of the manufacturers.
Joint operation of the construction hoist with cranes is carried out in accordance with the table of joint safe operation, while
The mounting console of the lift must always be at least 0.5 m below the mounting horizon.
Moving the crane boom with a load on the hook above the hoist is possible only when the hoist is not working.
For the period of operation of the crane in the area of operation of the lift, the latter must be turned off, and the keys to the power supply cabinet, knife switch, cab doors, lower guard of the lift must be kept by the lift driver. The operation of the lift is stopped if the distance from the danger zone of the crane to the lift is less than 2 m, the danger zone is determined by the height of movement above the level of the exit from the cab.
To ensure the joint safe operation of cranes and hoists, it is planned to install a single switch for cranes and hoists - in one position of the switch, only the crane works, in the other - only the hoist, in the third - the line is de-energized and the mechanisms do not work. Installation in the appropriate position of the knife switch is carried out by a person responsible for the safe performance of work with cranes.
When the crane and the hoist work together on the mounting horizon, a light alarm can be arranged at the hoist, which turns on when the power supply of the hoist is turned on, and during its glow, the crane operator must not bring the load to the hoist to the extent of the danger zone provided for in the PPR. As the building is erected, the signaling is moved from one mounting horizon to another. The light signaling must be clearly visible from the crane cab.
On the joint work of a passenger-and-freight hoist and a tower crane, in accordance with the schedule of their work, a special briefing is carried out with the driver-conductor and the crane driver, with an entry in the logs of these machines.
The basic rules for using the lift should be posted on the platforms from which the cab is loaded or unloaded.
The rules for using the lift must contain the method of loading, the method of signaling, the procedure for servicing the doors by duty workers, the prohibition of people entering the platform of cargo construction hoists, the prohibition to load the cabin with flammable and explosive goods and poisonous liquids in glass containers without special packaging and other instructions for servicing the lifts.
Table of masses of goods supplied to the remote platform
XIII. Storage of materials, structures, products and
equipment
13.1. The surface of the site for storing materials, structures, products and equipment must be planned and compacted. In case of weak soils, the surface of the site can be compacted with crushed stone or paved with road slabs on a sandy base.
Storage of materials is carried out outside the soil collapse prism of loose excavations, and their placement within the soil collapse prism near recesses with fastening is allowed subject to preliminary verification of the stability of the fixed slope according to the fastening passport or calculation taking into account the dynamic load.
Loads (except for ballast unloaded for track work) with a stack height of up to 1.2 m must be at least 2.0 m from the outer edge of the head of the crane rail closest to the load, and at a higher height - at least 2.5 m according to the requirements of GOST 12.3.009-76*.
To drain surface water, a slope of 1 - 2 ° should be made towards the outer contour of the warehouse with the device, if necessary, ditches.
13.2. Slingers must know the places for storing materials provided for in the PPRk.
Database of normative documentation: www.complexdoc.ru
13.3. Places for storing materials and structures, as well as places for installing warehouse inventory, are marked out at the construction site according to the example in Figure 34.
1 - brick on pallets; 2 - spacer-floor slabs - h up to 2.5 m; 3-
span slabs - h up to 2.5 m; 4 - outer spacer plates - h up to 2.5 m; 5 - stiffening walls - h up to 2.5 m; 6 - crossbars - h up to 2 m; 7 - flights of stairs - h up to 2 m; 8 - wall panels in the pyramid - h up to 2 m; 9 - stained-glass windows in the pyramid; 10 - partitions in the pyramid with shelter from atmospheric precipitation; 11 - columns - h up to 2 m; 12 - platform for tilting structures.
Rice. 34. Approximate plan for the placement of goods in the on-site warehouse
N o t e
1. Warehousing is carried out in such a way that the weight of the structures corresponds to the lifting capacity of the crane.
2. Temporary roads are arranged in such a way as to ensure the acceptance of all goods within the capacity of the crane.
3. The R/Q scale (may not be shown in the PPRk) will facilitate the layout of goods within the limits of the crane's load characteristics.
4. At the storage site, signs with the name of the goods and their quantity in piles are installed.
13.4. Materials, structures, products and equipment should be placed in accordance with the requirements of standards,
Database of normative documentation: www.complexdoc.ru
intersectoral rules on labor protection during loading and unloading operations and placement of goods, SNiP 12-03-2001 or technical specifications of manufacturers.
13.5. In the absence of standards and specifications of manufacturers, the following methods of storage of the main types of materials and structures are recommended:
- bricks in bags on pallets - no more than two tiers; in containers - in one tier, without containers - no more than 1.7 m high. Brick should be stored according to grades, and facing - according to colors and shades. In autumn and winter, brick stacks are recommended to be covered with sheets of roofing felt or roofing material;
- wall panels - in pyramids or special cassettes in accordance with the passport for the specified equipment, taking into account the geometric dimensions of the products and their stability during storage;
- partition panels - vertically into special cassettes in accordance with the passport for the cassette. Gypsum concrete panels are allowed to be installed in a pyramid with a deviation from the vertical by an angle of not more than 10 °. Gypsum concrete partitions must be covered from atmospheric precipitation;
- wall blocks - in a stack in two tiers on linings and with gaskets;
- floor slabs - in a stack with a height of not more than 2.5 m on linings and with gaskets, which are located perpendicular to the voids or the working span;
- crossbars and columns - in a stack up to 2 m high on linings and with gaskets;
- foundation blocks and blocks of basement walls - in a stack with a height of not more than 2.6 m on linings and with gaskets;
- stiffening walls, depending on the type of their transportation from the factory - in pyramids or similarly to floor slabs;
- round wood - in a stack no more than 1.5 m high with spacers between rows and installation of stops against rolling; stack width less than its height is not allowed;
Database of normative documentation: www.complexdoc.ru
- lumber - in a stack, the height of which, when stacked in rows, is not more than half the width of the stack, and when stacked in cages, not more than the width of the stack. In any case, the height of the stack should not exceed 3 m;
- low-grade metal - in a rack with a height of not more than 1.5 m;
- sanitary and ventilation units - in a stack with a height of not more than 2.0 m on linings and with gaskets;
- large-size and heavy-weight equipment and its parts -
in one tier lined;
- glass in boxes and rolled materials - vertically in one row on linings;
- bitumen - in a special container, excluding its spreading;
- ferrous rolled metals (sheet steel, channels, I-beams, section steel) - in a stack up to 1.5 m high on linings and with gaskets;
- heat-insulating materials - in a stack up to 1.2 m high, stored in a closed dry room;
- pipes with a diameter of up to 300 mm - in a stack up to 3 m high on linings and with gaskets with end stops;
- pipes with a diameter of more than 300 mm - in a stack up to 3 m high in a saddle without gaskets with end stops.
The lower row of pipes must be laid on linings, reinforced with inventory metal shoes or end stops securely fastened to the lining.
When storing reinforced concrete elements with hinges (slabs, blocks, beams, etc.), the height of the spacers must be at least 20 mm greater than the protruding part of the mounting hinges.
Storage of other materials, structures and products should be carried out in accordance with the requirements of standards and specifications for them.
Database of normative documentation: www.complexdoc.ru
13.6. Between the stacks (racks) there must be passages with a width of at least 1 m and driveways, the width of which depends on the dimensions of the vehicles and cranes serving the warehouse.
13.7. When storing goods, the factory marking must be visible from the side of the aisles.
13.8. It is advisable to place panels of the same brands in pyramids. The panels must fit snugly against each other over the entire plane. One-sided loading of pyramids is not allowed.
In cassettes, pyramids and other equipment of an on-site warehouse, it is necessary to install products in such a way that both the products themselves and the storage equipment cannot lose stability during storage. Products are installed taking into account their geometric dimensions and shapes.
13.9. Between stacks of structures of the same name, stacked side by side (floor slabs), or between structures in a stack (beams, columns), there must be a distance of at least 200 mm.
13.10. The height of a stack or row of stacks on a common spacer should not exceed one and a half of its width.
13.11. In stacks, gaskets are arranged one vertically. The location of the gaskets depends on the operating conditions of the product in the structure.
13.12. Each stack should store structures and products of one-dimensional length.
13.13. When arranging materials and structures, it is necessary to take into account the requirements PPB 01-03.
Storage of materials and structures above underground utilities or in a security zone is allowed only with the written permission of their owner.
13.14. When conditions change or in the event of a production need, the person responsible for the safe performance of work by cranes may make additions and changes to the scheme for storing materials and structures provided for in the PPR, in compliance with the requirements of standards, specifications of manufacturers and other regulatory and technical
| NAME OF ELEMENTS | BRAND TYPE | WEIGHT t | №№ SCHEMES OF STRINGS | CARGO ACCESSORIES | QTY | |||||||
| AT UNLOAD | INSTALLATION | AT UNLOAD | INSTALLATION | WHEN UNLOADING | INSTALLATION | CHARACTERIST. | ||||||
| Q, ts | L, mm | R, kg | ||||||||||
| Truss trusses | FBM24IV-9AIVB1 | 15,5 | Traverse | |||||||||
| Traverse | ||||||||||||
| Sling universal | 12,05 | |||||||||||
| Sling universal | 12,05 | |||||||||||
| FBM24IV-9AIVB1 | 15,5 | Traverse TR20-5 | ||||||||||
| Traverse TR20-5 | ||||||||||||
| Truss trusses | FPU-3 | 10,3 | 2-leg sling | 166,0 | ||||||||
| 2-leg sling | 166,0 | |||||||||||
| Sling universal | 14,5 | |||||||||||
| Sling universal | 14,5 | |||||||||||
| FPU-5 | 10,3 | 2-leg sling | 166,0 | |||||||||
| 2-leg sling | 166,0 | |||||||||||
| Sling universal | 14,5 | |||||||||||
| Sling universal | 14,5 |
SLINGING SCHEME
| NAME | LOADING CAPACITY, Q, tf | STRING LENGTH L, mm | DOWN WEIGHT Р, kg | ARCHIVE NUMBER | REQUIRED QUANTITY, pcs |
| 4-leg sling | 89,9 | 29700-102 VNIPI PSK | |||
| Capture KR-3.2 | 3,2 | 4,0 | 29700-108 VNIPI PSK | ||
| Sling VK-4-2 | 7,7 | 29700-109 VNIPI PSK |
TABLE OF WEIGHTS OF LOADS AND APPLIED LOAD HANDLING DEVICES
| NAME OF ELEMENTS | BRAND TYPE | WEIGHT t | №№ SCHEMES OF STRINGS | QTY. SIMULTANEOUSLY WE RAISE. EL-TOV | CARGO ACCESSORIES | QTY | ||||||
| AT UNLOAD | INSTALLATION | AT UNLOAD | INSTALLATION | WHEN UNLOADING | INSTALLATION | CHARACTERIST. | ||||||
| Q, ts | L, mm | R, kg | ||||||||||
| Metal crane beams | up to 10 t | 4-leg sling | 89,9 | |||||||||
| 4-leg sling | 89,9 | |||||||||||
| Sling VK-4-2 | 7,7 | |||||||||||
| Sling VK-4-2 | 7,7 | |||||||||||
| Capture KR-3.2 | 3,2 | 4,0 | ||||||||||
| Capture KR-3.2 | 3,2 | 4,0 |
SLINGING SCHEME
LIST OF LOAD HANDLING DEVICES AND PACKAGING
| NAME | LOADING CAPACITY, Q, tf | STRING LENGTH L, mm | DOWN WEIGHT Р, kg | ARCHIVE NUMBER | REQUIRED QUANTITY, pcs |
| 4-leg sling | 45,0 | 1028/3 SKB MS |
TABLE OF WEIGHTS OF LOADS AND APPLIED LOAD HANDLING DEVICES
| NAME OF ELEMENTS | BRAND TYPE | WEIGHT t | №№ SCHEMES OF STRINGS | QTY. SIMULTANEOUSLY WE RAISE. EL-TOV | CARGO ACCESSORIES | QTY | ||||||
| AT UNLOAD | INSTALLATION | AT UNLOAD | INSTALLATION | WHEN UNLOADING | INSTALLATION | CHARACTERIST. | ||||||
| Q, ts | L, mm | R, kg | ||||||||||
| Coating slabs | 2PG6-5AIVT | 1,5 | 4-leg sling | 45,0 | ||||||||
| 4-leg sling | 45,0 | |||||||||||
| PV10-6AIVT | 3,6 | 4-leg sling | 45,0 | |||||||||
| 4-leg sling | 45,0 |
ORGANIZATION AND TECHNOLOGY OF WORKS
3.1. Installation of prefabricated reinforced concrete structures should be carried out with clamps assigned in each specific case by the project for the production of works or technological maps and diagrams.
In this operational and technological map, the installation of structures is provided for by separate and combined methods in the following technological sequence:
Installation of columns and installation of metal ties with alignment and final sealing of concrete joints in the glasses of foundations;
Installation of crane beams with alignment and their final fixing;
Installation of truss trusses with alignment and their final fixing;
Installation of roof trusses and laying of floor slabs.
3.2. Unloading and layout of structures at their installation sites should be carried out in a separate stream by the main installation crane in the third shift in accordance with the instructions of the PPR.
3.3. Installation of columns (diagrams in Fig. 6).
TECHNOLOGICAL SCHEME OF INSTALLATION OF COLUMNS
SECTION II
Legend:
Crane station numbers
Danger zone boundary
Crane direction
Column installation order
Installed column
3.3.1. The installation of columns should be started only after preparing the bottom of the glass and instrumental verification of the design position of the foundation glass in plan and in height.
3.3.2. Before installing the columns in the foundation glasses, the following work must be performed:
The columns are laid out within the range of the erection crane in the “flat” position on backing bars 250 mm high;
The risks of the installation axes are applied on the upper faces of the glasses of the foundations and on the columns;
Welded overhead parts in accordance with the project.
3.3.3. The installation of columns in the glasses of the foundations is carried out immediately in the design position according to the risks on the reinforced concrete pads with a size of 100x100 mm and a thickness of 20 and 30 mm (Fig. 7). The number of reinforced concrete pads depends on the size of the gap between the bottom of the cup and the supporting part of the column and the thickness of the pads. The gap is determined by the formula = H - h - L (Fig. 7),
where: H - design mark of the console or top of the column;
h - actual mark of the bottom of the foundation glass;
L is the actual size from the console or top of the column to its bottom.
1 - column; 2 - foundation glass; 3 - reinforced concrete lining; - gap between the bottom of the glass and the column; H - design mark of the console or top of the foundation; h - actual mark of the bottom of the foundation glass; L is the practical dimension from the console or top of the column to its bottom.
Rice. 7 Schemes for installing reinforced concrete pads
1. Selection of slings for transported goods
The choice of slings begins with determining the mass of the load and the location of its center of gravity. If there are no such designations on the cargo, then it is necessary to clarify these parameters with the person responsible for the lifting operations. In all cases, make sure that the load to be moved can be lifted with the lifting equipment at your disposal. Having determined the mass of the load to be lifted and the location of the center of gravity, then determine the number of lashing points and their location in such a way that the load cannot tip over or turn around on its own. From this calculation, a sling or a suitable lifting device is selected. At the same time, the length of the selected multi-branch sling lifting device should be taken into account.
When choosing the length of the sling, one should proceed from the fact that with a short length, the angle between the branches of the slings will be more than 90 °, and with a long length, the lifting height of the load is lost and there is a possibility of its torsion. The optimal angles between the branches of the slings are within 60 - 90 ° (Fig. 1).
When choosing slings, you should also determine what elements the flexible part of the sling should consist of (steel rope or chain, or another type of rigid sling, etc.) and which end and gripping elements are more appropriate to use for lifting a particular load.
Fig.1. Scheme of distribution of loads on the branches of the sling: I - the recommended area for capturing the load; II - not recommended cargo capture area
2. Choice of cargo sling
Having determined the mass of the load to be lifted, then it is necessary to choose the right sling, taking into account the load that occurs in each of its branches. The load falling on each branch varies depending on the number of places where the load is hooked, on its size, on the angle between the branches of the sling, on the length of its branches. The forces arising in the branches of the sling when lifting the load can be determined in two ways (Fig. 2).
Fig.2. Sling tension scheme.
3. Methods for calculating the forces in the branches of the sling
1. The load on each branch of the sling can be determined by the first method as follows
S = G g/(k n cosα), (1)
where: S - Tension of the sling branch. H (kgf)
G - Weight of cargo. H (kgf)
g - free fall acceleration (g=9.8 m/s2)
n - The number of branches of the sling.
α - The angle of inclination of the branch of the sling (in degrees).
2. For ease of calculation, replacing ~1/cosα by the coefficient m, we obtain
S = m G g/(k n), (2)
where: m - Coefficient depending on the angle of inclination of the branch to the vertical;
at α = 0º - m = 1
at α = 30º - m = 1.15
at α = 45º - m = 1.41
at α = 60º - m = 2.0.
Ropes must be checked for strength by calculation: P/S ≥ k,
where: P is the breaking force of the rope as a whole in H (kgf) according to the certificate.
S - the maximum tension of the rope branch H (kgf).
k - must comply with the indication of the table - safety factor:
for chain = 5
for cable cars = 6
for textile = 7.
The values of the quantities used in the calculation formula (2) are given in Table. #1:
Table No. 1. Values of the quantities used in the calculation formula (2).
4. Examples.
Example #1.
When lifting a load with a mass of 1000 kg, the number of branches of the sling n = 4 and α = 45 ° we have
S \u003d 1.42 10,000 9.8 / (4 0.75) \u003d 46,390 N,
The lifting force per one branch of the sling is ~50 kN.
Example #2.
When calculating the forces in the branches of the sling in the second way, we measure the length C of the branches (in our case 3000 mm) and the height A of the triangle formed by the branches of the sling (in our case 2110 mm). The obtained values are substituted into the formula
S = G C g/(A n k).
The load on one branch of the sling S = 10 000 3000 9.8 / (2110 4 0.75) = 46 450 N, i.e. also equal to ~ 50 kN.
The load per branch of the sling is directly proportional to the angle between the branches of the sling and inversely proportional to the number of branches. Thus, in order to lift a particular load with an existing sling, it is necessary to check that the load on each branch of the sling does not exceed the allowable one indicated on the tag, brand or in the passport. In accordance with the current rules of Rostekhnadzor, the carrying capacity of slings with several branches is calculated taking into account the angle between the branches of 90 °. Therefore, when working with group slings, it is only necessary to ensure that the angle α does not exceed 45 °.
If the load is tied with single-branch slings, for example, lightweight, designed for a vertical position (α = 0 °), then it becomes necessary to take into account changes in the angle and, consequently, the load on the branches of the sling.
The loads acting on one branch of the sling at various angles between the branches are given in Table. 2.
Table No. 2. Loads acting on the branch of the sling, kN.
| Weight of cargo, kg | The angle between the branches of the sling | |||||||
|---|---|---|---|---|---|---|---|---|
| 0° | 0° | 60° | 60° | 90° | 90° | 120° | 120° | |
| 2 | 4 | 2 | 4 | 2 | 4 | 2 | 4 | |
| 530 | 2,5 | 1,25 | 3 | 1,5 | 3,5 | 1,75 | 5 | 2,5 |
| 630 | 3,15 | 1,57 | 3,78 | 1,89 | 4,45 | 2,22 | 6,3 | 3,15 |
| 800 | 4,2 | 2,1 | 4,5 | 2,25 | 5,75 | 2,88 | 8 | 4 |
| 1000 | 5 | 2,5 | 5,75 | 2,78 | 7,6 | 3,8 | 10 | 5 |
| 1250 | 0,25 | 3,13 | 7,25 | 3,63 | 9 | 4,5 | 12,5 | 6,25 |
| 1600 | 8 | 4 | 9,6 | 4,8 | 11,28 | 5,64 | 16 | 8 |
| 2000 | 10 | 5 | 11,5 | 5,75 | 14,25 | 7,13 | 20 | 10 |
| 2500 | 12,5 | 6,25 | 14,5 | 7,25 | 17,75 | 8,88 | 25,6 | 12,8 |
| 3200 | 16 | 8 | 19,2 | 9,6 | 22,56 | 11,28 | 32 | 16 |
| 4000 | 20 | 10 | 23 | 11,5 | 28,5 | 14,25 | 40 | 20 |
| 5000 | 25 | 12,5 | 28,75 | 14,38 | 35,5 | 17,75 | 50 | 25 |
| 6300 | 31,5 | 15,75 | 37,8 | 18,9 | 44,42 | 22,21 | 63 | 31,5 |
| 8000 | 40 | 20 | 46 | 23 | 56,75 | 28,33 | 80 | 40 |
| 10000 | 50 | 25 | 52,5 | 28,75 | 71 | 35,5 | 100 | 50 |
| 12500 | 62,5 | 31,25 | 72,5 | 36,25 | 90 | 45 | 125 | 62,5 |
| 16000 | 80 | 40 | 96 | 48 | 119,8 | 56,4 | 160 | 80 |
| 20000 | 100 | 50 | 115 | 57,5 | 142,5 | 71,25 | 200 | 100 |
When slinging a load with a group sling, the load on its branches, if there are more than three of them, is in most cases distributed unevenly, so it is necessary to strive to hook the load in such a way that all branches of the sling after hooking and tension have, if possible, the same length, symmetry of location and the same tension.
5. Technical examination of cargo handling equipment
The technical condition of the load-handling devices is checked by inspection and testing. They are subject to survey (Table 3) before commissioning and periodically during operation.
Table No. 3. Norms and terms for the examination of cargo handling equipment.
Lifting devices need not be tested if they are new, tested by the manufacturer and free from external defects. When inspecting the load-handling device, its general condition and the degree of wear of the clamps, nuts, cotter pins, braids, welded joints, armor, etc. are checked. If the load-handling devices are not rejected during external inspection, then they are tested under load. To do this, according to the passport, magazine or calculation, the maximum workload is determined. Based on the workload, a test load equal to 1.25 workload is selected.
During the test, the calibrated load is captured by the device under test, lifted by a crane to a height of 200 - 300 mm from the floor level and kept on weight for 10 minutes. Many factories have stationary test benches.
If, after the test, no damage, breaks, cracks, residual deformations are found on the fixture, then it is considered fit. Residual deformations are determined by comparing the nominal dimensions of the elements of the load handling device before testing with the actual dimensions after testing.
If the details of the fixture have received residual deformations that are unacceptable according to the standards, then it is allowed for operation only after a thorough inspection and recalculation for a new load capacity, as well as after a subsequent test. A tag is attached to the tested device, on which the number, load capacity, and date of the test are indicated.
The results of the survey are recorded in the register of cargo handling equipment. The journal contains complete information about each device: serial number, purpose, technical characteristics, manufacturer's name, date of manufacture, conclusion of the Quality Control Department on the test results.
At each enterprise, construction, base where there are cranes, a specialist, engineer or mechanical technician is appointed responsible for the safe operation of cranes, lifting equipment and their technical certification. In large organizations, a supervisory engineer may be vested with the rights of an inspector of Rostekhnadzor of Russia.
Before slinging the load, you need to know its mass,; In the absence of data on the mass of the cargo, you can
^approximately determine it by the formula>;*|
Q= tsh
|where Q~ weight of cargo, kg; ■ t- density, kg/m 3 ; , V- volume cargo, m 3.
The density of the most common materials is given in table. 6*!? *-
When choosing a crane and a removable load-handling device, I should select them with a margin of load- | | capacity. ■ ■. . ■ ■ .. ,
Table b
Center definition gravity of the transported cargo
When slinging cargo, you need to know its position | | center of gravity.
Ignorance of the center of gravity can lead to overloading individual lifting equipment* Loss of steady-gsti and overturning of the load.
Works were carried out on the manufacture of metal ■ structures. The supply of metal products for assembly was carried out with the use of a shov & go crane KS-50^ 42B.
The slinger, in violation of the slinging scheme, rattled
\ capture one corner 250x20 mm, length 12 m, weight 900 kg.
1 When lifting a load to a height of 1 m due to incorrect determination
1 center of gravity tapes lifted [corner at one end caught on the top package of a stack of rolled metal. At the same time, the grip was weakened, the corner fell on the slinger, causing him a fatal injury.
The center of gravity of goods with simple geometric
"Kie forms (pipes, concrete blocks, slabs, etc.) match-
| gives with their geometric center.
It is more difficult to determine the center of gravity of a load that has a complex geometric shape (Fig. 45). In such
I cases the position of the center of gravity (X) determined by the
I mule-" ■" ■■
rae" : (2i and Q2- mass of individual cargo elements;;■, ■ ■ i "■■■"-■■■■■■ :-X( and Xf- the distance from the center of gravity of an individual load element to a plane passing through one of the. extreme points of the load and its perpendicular axis;
Q- total mass, load.
On the package, using handling signs, the place of the center of gravity is indicated if it does not coincide with the geometric \ the center of the load.
Requirements to the site for the installation of a self-propelled jib crane on a slope not exceeding the value specified in the passport
The bearing capacity of the subgrade must correspond to the maximum bearing pressure of the crane at the highest load.
If there is no confidence in the soil foundation of the site, the laying of underlying means (sleepers, slabs, rolled metal shields, etc.) should be used. It is not allowed to install cranes on freshly poured uncompacted soil. ■■■■■.
When installing a crane on the territory of an existing enterprise or near buildings and structures,
take into account that underground at a shallow depth there may be various pipelines, underground structures that may not withstand the additional load. ...■■■■ .
At the power plant near the boiler shop, work was carried out using a KS-3574 truck crane. During the installation of adjustable retractable supports, the underground gas duct of the operating boiler, laid under the crane installation site, was destroyed. Two workers who were near the scene fell into a collapsed gas duct and died.
Bricklaying of the walls of the repair shop was carried out. Mortar and bricks were supplied using a pneumatic wheeled crane KS^4361. The crane operator, having approached the place of work, stopped the crane according to the design and survey, but then decided to approach the wall being built. At the same time, the crane boom moved the floor slab, which led to its fall. One of the masons was fatally injured.
Safety requirements for the installation of cranes moving along elevated crane tracks
During installation and further operation of cranes moving along elevated crane tracks, it is necessary to maintain the distances indicated in Fig. 46.
It is necessary to provide free passage for the worker if the crane is controlled by him from the floor or by radio.
Above the roadway and above the passages for people; it is necessary to install safety protective: ceilings (nets, etc.), which the load must withstand "\ъ case of his fall. ; !
Safety requirements for installation of cranes moving along ground crane tracks
During installation and further; operation of cranes, S moving along the ground crane tracks, it is necessary to maintain the distances indicated in fig. 47.
The installation of cranes in the security zone of overhead power lines must be agreed with the owner of the line.
Installation of cranes to perform construction and installation | works... V.."/ ;.;, -";d.,. ; . ■■:,..-.:
The installation of cranes for construction and installation work must be carried out in accordance with the project for the production of works.
^Rules for the installation of self-propelled jib cranes near the I slopes of pits and trenches
When installing the crane on non-filled soil, it is necessary to maintain safe distances from the base from the slope of the pit (trench) to the crane support, indicated in Table. 7. The distance from the base of the slope of the pit (trench) to the support, crane (overturning rib) is determined sch depending on the type of crane (Fig. 48),
With the use of an automobile crane SMK-10, a bucket with a solution was lowered into the pit. The crane was installed on bulk uncompacted soil. As a result of the subsidence of one of the outriggers, the crane tilted, the bucket of mortar pressed against the formwork of the concrete worker, causing him a fatal injury.
The procedure for lifting the boom of a self-propelled boom crane from transport position to the working position when working in the security zone of the power line or at a distance of less than 30 m to the outermost wire of the power line
The crane operator can raise the boom to the working position
Tabyaida, 7
only after the person responsible for the safe performance of work with cranes makes an entry in the watch log: "I checked the installation of the crane at the place indicated by me. I authorize work."
Previously, the crane must be grounded with a portable ground electrode system, outriggers must be installed, if required by the instructions"
Slinging cargo with a protracted ^loop,< ; sch
■-, .S :■ _ , -"■ -.i ■■:
When slinging loads with a long loop (Fig. 49), it is recommended to reduce the load capacity of the sling by 20%, since this causes deformation of the rope cross section. ",■■:/ " ,.\-.;. ,.-: ?. .„ ■ :-;■.
