The scaffolding consists of milestones on the selection of the required brand, fastening structures to walls and other structural elements buildings and structures. Scaffolding and scaffolding are used at every facility and almost nowhere can you do without them. The following types are used:
- frame (LRSP), consisting of finished welded frames (individual elements), from which scaffolding is assembled;
- pin (LSh, LSPSh) - a design of racks with pins, crossbars and jibs, providing a single rigid system;
- clamp (LH, LSPH) - assembly is carried out using clamps, which greatly complicates the process of their assembly, but allows you to assemble the scaffolding structure of any shape;
- wedge (CL) - represent the same spatial-tiered system as the previous ones, but differ in the presence of an adjustable wedge-shaped connection;
- tower tours, both mobile, equipped with wheels, and stationary - represent one section of scaffolding, assembled to the required height; are used most often for anti-corrosion and fire protection of building structures.
All scaffolding is intended both for finishing, repair, and for a complex of installation and dismantling works, brickwork of walls, laying pipelines and cables along overpasses, installation of video surveillance systems on buildings, etc. their application. Separately, the WEP should include technological maps for the assembly of the structures themselves.
The graphical part of the PPR for the installation of scaffolding should provide for the boundary of the danger zone for flying off falling objects, and in the event that it is necessary to reduce it, then the use of protective nets. In accordance with the rules for labor protection at height, fences for safe production works. In the detailed design of the production of works, instructions are given on the appointment of scaffolding for their use only when they were provided. When developing documentation, we take into account all current rules on labor protection in construction and work at height.
Order PPR for the installation of scaffolding
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Technological maps for scaffolding
Technological maps for the arrangement and operation of scaffolding provide for all assembly activities in accordance with the manufacturer's instructions. Assembly steps should include a complete set of the object necessary quantity elements depending on the type of scaffolding used:
- thrust bearings for racks with adjustable installation height on uneven grounds;
- ordinary and additional vertical racks;
- horizontal and transverse connections for attaching racks to each other and creating spatial rigidity of the structure;
- ladders in finished design for moving along the tiers;
- floorings on tiers from a board or inventory factory execution;
- anchor fasteners for fastening scaffolding to the structures of buildings and structures;
- fastening elements (clamps, cotter pins, hardware, etc.).
A technological map for the installation of scaffolding is developed with reference to a specific construction site. A prerequisite is the installation site, the definition of the boundaries of the danger zone, the installation of protective fences, fastening to existing structural elements of buildings and structures. Selection by load capacity is carried out based on the carrying capacity of the scaffolding and the need for simultaneous work from several tiers.
Methodological documentation in construction
INSTALLATION OF SCAFFOLDINGS
FOR HIGH-RISE BUILDINGS.
PROJECT OF WORK PRODUCTION
MDS 12-57.2010
Moscow 2010
The document was drawn up in the development and addition of MDS 12-25.2006, MDS 12-40.2008, MDS 12-46.2008.
The document was developed by the employees of REMSTROYSERVICE-R LLC (E.V. Gnatyuk, B.A. Mordkovich) and ZAO TsNIIOMTP (Yu.A. Korytov).
The document is intended for design organizations that develop projects for the production of works, and for construction and installation organizations that carry out installation scaffolding to high-rise buildings.
INTRODUCTION
In megacities of Russia, there is an increase in the volume of construction of high-rise (from 30 floors and above) monolithic reinforced concrete residential and public buildings. On the facades of these buildings are carried out using scaffolding various works: finishing, insulating and others.
Scaffolding is applicable for buildings with a variety of architectural, planning and design parameters, configuration, height and length.
Forests are indispensable in the cramped conditions of urban development, where they are used as universal remedy pavement, as well as for placement building materials and façade structures.
The complexity of scaffolding installation does not exceed, as a rule, 0.6 man-hours per 1 m 2 of the facade area.
Projects for the production of works for the installation of scaffolding are part of the main organizational and technological documents for the construction and are in demand by local state supervision authorities when registering permits on the construction works.
The document is applicable directly to the installation of the most widely used scaffolding, manufactured according to the specifications of GOST 27321-87. In this project for the production of work, tubular, clamp scaffoldings are used, the racks of which are joined using branch pipes.
The project for the production of works consists of text and graphic parts. The graphic part is represented by diagrams of nodes, installation sequence, scaffolding attachment to the wall, scaffolding support device on the floor of the building.
This methodological document is intended to assist design, design and construction and construction organizations in the development of a project for the production of work for the installation of high-altitude scaffolding.
The methodological document is based on the results of the work of ZNIIOMTP CJSC and other design and technological institutes, as well as a generalization practical experience installation of scaffolding LLC "REMSTROYSERVIS-R" and other Moscow construction organizations.
1 CHARACTERISTICS OF THE BUILDING AND SCAFFOLDING
The residential monolithic reinforced concrete building has a complex shape with rectangular and oval outlines of the walls, overall dimensions: length along the facade is not less than 50 m, width - 30 m, height - up to 160 m. Thickness of walls and interfloor ceilings - not less than 200 mm, window and other openings allow mounting supporting devices in them for the installation of scaffolding at height.
The project for the production of works for the installation of scaffolding was developed on the basis of the contract, terms of reference and the submitted initial data. As part of the terms of reference and initial data: working documentation for construction work on the facade, a passport and instructions for the installation of scaffolding, drawings for the building (in the amount necessary for the installation of scaffolding).
This project for the production of works was developed with the following initial data.
Clamp scaffolding design - inventory, lightweight, collapsible, reusable. Scaffold turnover is at least 60 times, and the service life is at least 5 years.
Scaffolding, for example: LSPH-200-60 of the company "Metacon", rack-mounted attached clamps according to GOST 27321. The step of the tier in height is 2 m, the step of the posts along the wall is 2.5 m, the width of the passage between the posts is 1.25 m. The deck boards can be laid on all tiers at the same time. Normative load is not more than 200 kgf/m 2 . The maximum height of scaffolding is 60 m.
Scaffolding is assembled from tubular elements- racks and half-racks with a diameter of 60 mm, installed in support shoes with wooden linings, made of longitudinal ties with a diameter of 48 mm, connected to the racks using clamps, crossbars that fasten the scaffolding to the wall using metal or polymer plugs (dowels). On the extreme sections of the scaffolding, diagonal connections are established with the help of rotary clamps.
Racks and half-racks are joined using branch pipes.
Connections are interconnected with bolts.
Plugs are inserted into holes drilled in the wall. Hooks are screwed into the plugs, and the plugs are wedged. The lugs of the crossbars are put on the hooks, after which the crossbars are fastened with clamps to the uprights.
A non-rotating collar connects the uprights and half-uprights at right angles to the crossbars and railings. The swivel clamp connects the racks with diagonal ties at an acute or obtuse angle.
The extreme rows of racks are fixed through one tier in height, the inner rows of racks are fixed in a checkerboard pattern through two tiers in height and through two racks horizontally.
When using scaffolding in accordance with GOST 27321, for example, type LSPH-200-60 of the Metacon company, for installation on high-rise buildings, a number of measures justified by calculations are performed that are not provided for by the manufacturer.
To increase the bearing capacity of high-rise scaffolding, the so-called double racks made of pipes with an outer diameter of 60 mm are used, which are the main element of high-rise scaffolding and the main condition for mounting standard scaffolding on high-rise buildings. Load bearing capacity racks must be checked by calculation, the load on the rack should not exceed 3 tf. The actual load on the most loaded racks should be selectively determined experimentally, using instruments, such as special scales, and recorded in the work log.
In addition to this main event, the following activities are also carried out.
So, the normative load on the forests is not set at 200 kgf / m 2, but reduced, for example, no more than 100 kgf / m 2.
To reduce the load on the scaffolding, the number of working and protective decks is reduced, according to the calculation. In this case, the flooring boards may not be laid on all tiers at the same time, but in turn and at random.
Depending on local conditions, it may be necessary to change the spacing of the posts along the wall: for example, not 2.5 m, but 2.6 m or 2.4 m.
The width of the passage between the uprights can be taken not as 1.25 m, but, for example, as 1.31 m.
The scheme of fastening scaffolding to the wall, specified in the manufacturer's operating instructions, can be changed.
Scaffolding may not be mounted on a dirt platform (without or with asphalt concrete pavement), and at a height - on supporting devices from cantilever beams.
With simple architectural and construction solutions for the building, one or two of the above activities are carried out. Modern architectural and construction solutions for the building are complex, which requires the development of almost all or all of the above measures and their appropriate reflection in the project for the production of works for the installation of scaffolding.
All these measures, as was said, must be justified by calculations and agreed with the manufacturer.
The implementation of the above activities allows you to apply various schemes installation of high-altitude scaffolding, depending on the configuration of the walls, the height of the building and other local conditions.
The project sets out provisions for the organization and technology of scaffolding installation, requirements for the quality and acceptance of work, determines the need for mechanization, tools, inventory and fixtures, specifies safety and labor protection requirements.
When developing the project, normative, methodological and reference documents specified in the List of used documents were used.
2 LIST OF USED DOCUMENTS
Installation workers are instructed on the procedure, techniques and rules for assembling and attaching scaffolding to the wall.
The plan of the scaffolding installation area is given in the project for the production of work on sheets, as a rule, of the A2 (420 × 594) or A3 (297 × 420) format.
On fig. 1 shows, as an example, a fragment of the plan of the scaffolding installation area on the grip corresponding to the factory set of scaffolding. Symbols according to RD-11-06, scaffolding, the boundary of the danger zone when an object falls from the scaffolding tier, and temporary fencing of the installation area are shown.
The boundary of the danger zone is established by calculation according to RD-11-06, depending on the height of the scaffolding layer.
LEGEND:
Load-bearing exterior walls
Scaffolding
boundary of the danger zone when an object falls from a scaffolding level
temporary fencing of the scaffolding area
Rice. one
3.1.2 Inspection, control and evaluation are carried out technical condition constituent parts mounted scaffolding.
Damaged components must be discarded.
The components sorted by detail are laid along the walls.
3.1.3 Preparation for work, installation and launch of lifting mechanisms (roof crane, jib crane, winch) for lifting and lowering scaffold components are being carried out.
These works are carried out in accordance with the instructions of the manufacturers of load-lifting mechanisms.
3.1.4 Means of mechanization (hand-held drilling machines, punchers, rammers, etc.) and tools are being prepared, their completeness and readiness for work are checked.
3.1.5 To support the scaffolding along the facade, a platform with a width of at least 3 m with an asphalt concrete coating or a planned and compacted soil platform is prepared. The bearing capacity of the sites is checked by calculation. Water drainage must be arranged from the site. If the soil is wet, then tamping is carried out with crushed stone, broken brick, concrete.
If there is a difference in height, then the site for scaffolding along the facade is aligned horizontally in the longitudinal and transverse directions.
To equalize the difference in height, standard concrete slabs and boards with a thickness of at least 40-50 mm can be used.
3.1.6 The marking of the installation points of anchor plugs on the wall of the building is carried out in accordance with the working drawing on the wall or "in place".
On the initial stage determine the lighthouse marking points of the wall in such a way that the points do not coincide with the window openings. If the attachment point coincides with the opening in the wall, the scaffolding is attached to the supporting structures (walls, columns, ceilings) with inside buildings with the help of fasteners and fixtures; it is not allowed to attach scaffolding to balconies, cornices, parapets.
The distance of the anchor plug installation point to the opening should be at least 150-200 mm. The horizontality of the extreme points is determined using a level, the points are marked with indelible paint. At two extreme points, using a laser level and a tape measure, intermediate points for installing anchor plugs are determined and marked with paint. Then, at the extreme points of the horizontal line, determine the vertical lines. With indelible paint mark the points of installation of anchor plugs on the extreme vertical lines.
3.2 Main works
3.2.1 Installation work from the zero mark is carried out with grippers, taking into account, as a rule, the use of one set of scaffolding supplied by the manufacturer for gripping. The volume of the capture is usually set to no more than 50 m along the facade of the building and a height of not more than 60 m. When installing scaffolding from a mark of 60 m and above, the height of the capture is taken to be no higher than 20 m.
To speed up the installation of scaffolding (if there are several sets of scaffolding), work can be carried out by several parallel grips.
An independent parallel grip can be organized when scaffolding is mounted on a support device made of cantilever beams, which is installed on an interfloor ceiling at a height, as a rule, above 60 m.
3.2.2 When using double racks up to a height of 80 m, and above single scaffolding, they are mounted to a height of up to 160 m. The distance between the twin racks is usually taken as 300 mm (Fig. 2)
Rice. 2
If the wall configuration does not allow the application of such a scheme, then the scaffolding is installed on the above supporting devices on the floor of the building. In this case, the height of the capture is taken no higher than 20 m.
3.2.3 The scaffolding is erected, according to the manufacturer's instructions, in tiers for the length of the grip.
The technological process of installation consists of assembling the first, second, third and other tiers, attaching scaffolding to the building and mounting support devices at a height.
3.2.4 Assembly of scaffolding tiers is carried out as follows. On prepared, flat horizontal plane platform (see) install shoes with screw height adjustment.
The height difference in the direction along the wall is leveled by laying concrete slabs and board linings.
Under the shoes of each pair of racks, a lining of a board with a thickness of at least 40-50 mm is laid in the transverse direction. Installation of shoes is shown in fig. 3, a.
The assembly of the main parts of the tiers is carried out in the following sequence.
Double racks of the inner and outer rows of scaffolding are installed in the shoes (Fig. 3 b).
Transverse and longitudinal ties are installed on the inner and outer rows of racks for supports of the first mounting tier (Fig. 3, c).
At each rack, shields are laid on longitudinal ties-supports of the first mounting tier.
From the platforms of the first mounting tier, longitudinal ties of the first working tier are installed and holes are drilled in the wall for plugs (dowels) for fastening the cross ties of the first working tier.
Plugs (dowels) are inserted into the holes and cross braces are attached to the wall.
Fences of the first working tier are installed from the platforms of the first assembly tier, corner posts are increased, shields of the assembly tier are transferred to the flooring of the first tier. The flooring is equipped with a side railing 150 mm high.
Racks are built up from the flooring of the first tier, a second mounting tier is installed, from which the second working tier is assembled.
The assembly operations for subsequent tiers are repeated.
Rice. 3
3.2.5 The scaffolding is fixed to the building to a reinforced concrete wall with a thickness of at least 200 mm using factory-made metal plugs or polymer dowels and through openings (window, door, balcony).
Fastening scaffolding with dowels is shown in fig. four.
Rice. four
Dowels, such as type MGD 14×100, bolt MUNGO MGV 12 × 350 with a ring is fixed in the wall after four meters in a checkerboard pattern according to the intended attachment points. The diameter and depth of the hole in the wall must comply with the values specified in the manufacturer's instructions.
The strength of fastening the dowels in the wall is checked by calculation and must be tested selectively using a device (device) for pulling the cork out of the wall. The pull-out force from the concrete must be at least 300 kgf.
If a hole is drilled in the wrong place by mistake and it is required to drill a new one, then the latter must be at least one depth of the drilled hole from the wrong one. This rule is not necessary if the erroneous hole is pre-concreted or filled with a polymer composition of the same strength.
Holes are cleaned from drilling waste (dust) with compressed air.
The dowel is inserted into the prepared hole and tapped with a mounting hammer.
Fastening scaffolding to the wall through a window opening is shown in fig. 5.
Rice. 5
The inventory fastening device is made, as a rule, from the same tubular elements as the scaffolding.
The elongated cross-links of the scaffolding are brought into the opening, then longitudinal pipes are laid on them close to the wall. Fastening of connections and pipes is carried out using clamps or in another way.
3.2.6 The support device at a height is mounted from two cantilever beams and spacers. The beams are laid on the ceiling through sheet metal linings so that the length of their cantilever part allows the scaffolding to be installed at a distance of 600 mm from the wall to the axis of the internal rack. Then, racks with screw mechanisms are installed on opposite ends of the beams. The upper supports of the racks with wooden spacers lead to the ceiling. With the help of screw mechanisms with a tightening torque of at least 5 kgf m, the racks abut against the floor and beams, pressing them against the floor and fixing the supporting device in the opening.
To fix the scaffolding on the support device, loops welded to the beams are used.
As cantilever beams, a channel according to GOST 8240 is most often used. The channel number (from No. 12 and more) is selected by calculation depending on the load from the scaffolding, which is determined by direct summation of the weight of the scaffolding parts (no more than 20 m high) and the working load. The weight of the cantilever beam should not exceed 140-150 kgf, provided that the assembly team performs the installation operations manually. Therefore, the channel number must correspond to the minimum allowable safety margin of the cantilever beam.
For spacer posts, mounting posts of a telescopic design with a screw mechanism for adjusting the height of the supports are used. The main parameters of the racks are: height up to 3100 mm, expansion force from 3000 to 5000 kgf (see MDS 12-41).
The values of spacer forces from the racks transmitted to interfloor ceilings, must be determined by calculation and selectively verified experimentally. The values and places of application of these forces from the racks must be agreed with the building design organization and entered in the work log. If it is necessary to temporarily strengthen the floors, mounting telescopic racks are installed on the underlying floors.
Rice. 6
3.2.7 The scaffold components are lifted to the mounting horizon using winches installed on the ground, roof cranes and jib cranes installed on interfloor ceilings in building openings.
The speed of movement of the cargo rope must be at least 50 m/min. To eliminate dynamic loads during acceleration and deceleration of the load, the speed of movement of the cargo rope must have a smooth frequency control.
The dismantling of scaffolding for their rearrangement to a new grip is carried out in the reverse order of their installation, that is, starting from the upper tier. Remains of building materials, inventory and tools are removed from the decks. The descent of the dismantled components of the scaffolding is carried out using the above winches and cranes.
4 QUALITY REQUIREMENTS AND WORK ACCEPTANCE
4.1 The quality of the scaffolding installation is ensured by the current control of the technological operations of the preparatory and main works, as well as during the acceptance of works. According to the results of the current control of technological operations, certificates of examination of hidden works are drawn up: for the strength of fastening plugs for scaffold anchors in the wall, for the stability and strength of fastening of scaffold support devices at a height.
4.2 In the process of preparatory work, check:
Readiness of the wall and structural elements of the building, means of mechanization and tools for installation work;
Condition of scaffolding parts (dimensions, absence of dents, bends and other defects of scaffolding parts);
The condition of the details of the supporting devices (the absence of defects in the cantilever beams and racks, the reliability of the beam loops);
The evenness and equal strength of the base points on which the shoes are installed.
4.3 In the process of installation work, check:
Wall marking accuracy;
The correctness and reliability of the installation of scaffolding shoes on the base;
Diameter, depth and cleanliness of holes for anchor plugs;
Strength of fastening of anchors;
The verticality of the racks and the horizontality of the connections, the flooring of the scaffolding.
Horizontal scaffolding in the longitudinal and transverse directions is provided by the level, verticality - by the plumb line.
When assembling scaffolding, it is necessary to ensure that the racks enter the nozzles to the design length.
When laying the flooring, the strength of the fixing and the absence of the possibility of shifts are checked.
4.4 When accepting work, the acceptance committee inspects the mounted scaffolding in general and especially carefully the attachment and junction points.
The horizontality and verticality of the forests are checked using geodetic instruments.
Defects found during the inspection are eliminated.
The scaffolding is subject to a standard load test within two hours in the presence of the acceptance committee. At the same time, their strength and stability, reliability of fastening to the wall and supporting devices, flooring and fences, and grounding are evaluated.
The railing of the fence must withstand a concentrated load of 70 kgf applied to them in the middle and perpendicularly.
Carriers horizontal connections must withstand a concentrated load of 130 kgf applied in the middle.
4.5 Acceptance of mounted scaffolding is documented by an act of acceptance of work. Certificates of inspection of hidden works (according to paragraph 4.1) are attached to the work acceptance certificate.
4.6 The quality of the scaffolding installation is assessed by the degree of compliance of the actual parameters and characteristics with the design ones specified in the design and regulatory and technical documentation.
The main controlled parameters and characteristics, methods for their measurement and evaluation are shown in Table 1.
Table 1
|
Technological |
Controlled parameter, characteristic |
Permissible value, requirement |
Method of control and tool |
|
|
Marking extreme points horizontally |
Marking Accuracy |
|||
|
Marking extreme points vertically |
Theodolite |
|||
|
Marking intermediate attachment points |
Level, plumb line, tape measure |
|||
|
Drilling holes for anchor plugs (dowels) |
Depth H |
H= screw length |
Depth gauge, inside gauge |
|
|
Diameter D |
D= screw diameter |
|||
|
Distance to the opening, corner of the building |
Not less than 150.0 mm |
|||
|
Hole cleanliness |
No dust |
Visually |
||
|
Installing shoes |
Board lining thickness |
Ruler metal |
||
|
Assembly of sections and tiers of scaffolding |
Deviation from verticality |
± 1.0 mm at 2 m height |
Plumb, ruler |
|
|
Deviation from horizontal |
± 1.0 mm per 3 m length |
Level, ruler |
||
|
Gap between building wall and deck |
no more than 150 mm |
|||
|
Linear dimensions |
Up to 50 m - ±1% |
Laser tape measure DISTO |
||
|
Attaching the scaffold to the wall |
The force pulling the anchor (dowel) out of the wall |
Not less than 500 kgf |
force measuring device |
|
|
Floor laying |
Gap between boards |
Not more than 5 mm |
||
|
board protrusions |
no more than 3 mm |
|||
|
Overlapping with joints of the flooring of supports |
Not less than 200 mm |
Ruler metal |
||
|
Rack installation |
Torque |
torque wrench |
||
|
Scaffold grounding device |
Ground resistance |
No more than 15 Ohm |
Testor Sch 4313 |
5 NEED FOR MECHANIZATION EQUIPMENT, TOOLS, INVENTORY AND ACCESSORIES
The need for fixed assets of mechanization, tools, inventory and fixtures is given in table 2.
table 2
|
Name |
Type, brand, GOST, drawing No., manufacturer |
Technical specifications |
Purpose |
|
|
Roof crane |
Type "Pioneer", CJSC "TEMZ" |
Load capacity 150- 500 kg |
Ascent and descent of scaffolding components, facade elements |
|
|
Variable speed winch |
Type LChS-3 |
Pulling force up to 250 kgf |
||
|
Plumb, cord |
Measurement limit 1.5-4.5 tf, weight 0.35 kg |
Rack Load Control |
||
|
torque wrench |
Measurement limits 3-8 kgf m, weight 3.5 kg |
Control of the strength of fastening of the mounting racks of the scaffold support device |
||
|
A device for measuring the force of pulling out a cork (dowel) |
Measurement limits 100-400 kgf. Dimensions: 1240×1200×175 mm. Weight - 7.8 kg |
Strength control of scaffolding attachment to the wall |
||
|
Fencing of the work site |
Inventory |
Work safety |
||
|
Protective mesh for scaffolding |
Types 4.603; 4.504; 4.501.1 Apex, Vert or others |
Made from polymer fibers |
Fall protection |
6 HEALTH AND SAFETY
6.1 When organizing and carrying out work on the installation of scaffolding, the requirements of SNiP 12-03, SNiP 12-04, GOST 12.4.011 must be met.
On the scaffolding, the layout and the values of permissible loads should be posted. The accumulation of three or more people on the scaffolding floor is not allowed.
Workers who have the right to work at heights are allowed to install scaffolding. Installers must be provided with safety belts.
6.2 Fire safety at the workplace should be provided in accordance with the rules of PPB-01.
6.3 Electrical safety at workplaces must be ensured in accordance with the requirements of GOST 12.1.019, GOST 12.1.030, POT RM-016.
6.4 When organizing work in the installation area, a danger zone is established from falling objects from the height of the scaffolding. The danger zone is indicated by safety signs and inscriptions of the established form in accordance with GOST R 12.4.026.
In each specific case, the project for the production of works must provide for such measures so that the danger zone does not go beyond the fenced area for scaffolding.
A protective net can be hung on the scaffolding. The danger zone may not be marked.
The location and design of the installation zone fencing must be taken in accordance with GOST 23407.
6.5 Warehousing and storage of components of scaffolding, materials, products and equipment must be carried out in accordance with the requirements of standards or specifications for scaffolding, materials, products and equipment, as well as SNiP 12-03.
6.6 When working at night, the installation area, scaffolding, driveways and approaches to them must be illuminated in accordance with GOST 12.1.046. Illumination should be uniform, without blinding effect of lighting fixtures.
6.7 Scaffolding ladders must be equipped in accordance with GOST 26887. The slope of the stairs to the horizon should be no more than 75 °. Stairs must be with non-slip steps.
6.8 Loads are lifted onto the scaffolding by a winch or a roof crane. Lifting loads onto scaffolding with tower cranes is unacceptable.
6.9 Lightning protection of scaffolding should be arranged with grounding resistance of not more than 15 ohms.
6.10 During the installation and dismantling of the scaffolding, electrical wires located closer than 5 m from the scaffolding are de-energized.
During thunderstorms, snowfalls and winds of more than 6 m/s, scaffolding is not erected or dismantled.
6.11 The technical condition of scaffolding is controlled before each shift and periodic inspections every 10 days.
Particular attention should be paid to the measurement and control of the actual loads on the posts and shoes, pulling out the forces of the anchors from the wall. At the same time, deformations of posts and shoes with wooden linings, crossbeams and anchors and their relative movement should be measured and evaluated.
If the scaffolding has not been used for a month, then they are allowed for use after acceptance by the commission. The results of acceptance and inspection are noted in the register in accordance with GOST 24258.
Scaffolding is subject to additional inspection after rain or thaw, which may reduce the bearing capacity of the base.
WORK PROJECT (PPR)
The project for the production of works for the installation of scaffolding LSPR-200
PPR is applicable directly to the installation of the most widely used rack-mounted scaffolding, manufactured according to the specifications of GOST 27321. Scaffolding can be of any degree of assembly (tubular, frame and frame) and diverse in design of nodal connections (clamp, hook, wedge or pin); at the same time, racks, frame and frame elements are joined using nozzles.
PPR consists of text and graphic parts. The graphic part is represented by schemes for fencing the danger zone, the sequence of installation, and fastening scaffolding to the wall.
The PPR has the following sections:
1. Explanatory note.
2. List of used documents.
3. Organization and technology of work.
3.1. Preparatory work.
3.2. Main works.
4.Requirements for quality and acceptance of work.
5. The need for mechanization, tools, inventory and fixtures.
6. Safety and labor protection.
7. Features of mounting scaffolding on high-rise buildings, on buildings with balconies (loggias).
8. Technical and economic indicators.
1. Explanatory note
1. Explanatory note
The design plan for the installation of scaffolding for the installation of a ventilated facade on the fitness center building was developed on the basis of the terms of reference and the submitted initial data. As part of the terms of reference and initial data: working documentation for the installation of a ventilated facade, a passport and instructions for the installation of scaffolding (for example, frame scaffolding LSPR-200), drawings for the building.
This PPR was developed with the following initial data.
Scaffolding LSPR-200 - attached, when installing a ventilated facade, they can reach a height of 40 m. The step of the tier in height is 2 m, the step of the frames along the wall is 3 m, the width of the passage between the racks is 0.95 m. The standard load at a height of more than 20 m no more than 100 kgf/m. Structural components of scaffolding LSPR-200 and their weight are shown in Table 1.1.
Table 1.1
|
Components of scaffolding LSPR-200 |
|
|
Frame (2x1 m) |
|
|
Frame with ladder (2x1 m) |
|
|
Communications (3.05 m) |
|
|
Communication diagonal (3.3 m) |
|
|
Shoe |
|
|
Cork-anchor |
|
|
Deaf clamp, 48x48 mm |
|
|
end fence |
|
|
decking crossbar |
The table shows that the weight of the components of the scaffolding does not exceed 12 kg and they can be lifted as a package to the mounting horizon using a winch or a roof crane with a lifting capacity of not more than 250 kg.
The building is rectangular in shape, the length along the facade is 72.0 m, the height is not more than 40 m.
A hinged facade system U-kon with facing elements is mounted on the facade of the building - ceramic tile and aluminum profiles. In accordance with this, the scaffolding is mounted along the facade in axes 1-12.
2. List of used documents
When developing the PPR, normative, methodological and reference documents were used, which are indicated in the list of references. The text also contains references to the following regulatory documents:
GOST 2.601-2006 ESKD. Operating documents
GOST 2.602-95 * ESKD. Repair documents
GOST 9.104-79 * ESKD. Paint coatings. Operating condition groups
GOST 7502-98 Metal measuring tapes. Specifications
GOST 7948-80 Construction steel plumb lines. Specifications
GOST 8486-86 * Softwood lumber. Specifications
GOST 9467-75 * Coated metal electrodes for manual arc welding of structural and heat-resistant steels. Types
GOST 15150-69 * Machines, instruments and other technical products. Versions for different climatic regions. Categories, conditions of operation, storage and transportation in terms of the impact of environmental climatic factors
GOST 23407-78 Inventory fences for construction sites and sites for construction and installation works. Specifications
MDS 12-41.2008 Mounting equipment for temporary fixing of prefabricated elements of erected and dismantled buildings.
3. Organization and technology of work performance
3.1. Preparatory work
Before starting installation work, the following preparatory work must be carried out:
- the working area (as well as approaches to it) is freed from extraneous building structures, materials, mechanisms and construction debris and is fenced in accordance with the requirements of GOST 23407;
- the scaffolding installation area is fenced in accordance with the requirements of SNiP 12-03, warning signs are installed in accordance with GOST 12.4.026 *;
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* GOST 12.4.026-76 has been canceled on the territory of the Russian Federation since 01.01.2003. GOST R 12.4.026-2001 is valid. (IUS N 12, 2001). - Database manufacturer's note.
- assembly workers are instructed on the procedure, techniques and rules for assembling and attaching scaffolding to the wall.
Figure 1 shows a fragment of a construction site plan as an example. Symbols show scaffolding, the boundary of the danger zone when an object falls from the last tier of scaffolding, and temporary fencing of the construction site.
Fig.1. Fragment of the construction site plan
Conventions
Load-bearing exterior walls
scaffolding
boundary of the danger zone when an object falls from a scaffolding level
temporary fencing for scaffolding
Inspection, control and assessment of the technical condition of the components of the mounted scaffolding is carried out. Damaged components must be discarded.
Preparation for work, installation and launch of lifting mechanisms (roof crane or winch) for lifting and lowering the components of the scaffolding are being carried out. These works are carried out in accordance with the instructions of the manufacturers of load-lifting mechanisms.
Means of mechanization (hand-held drilling machines, hammer drills, rammers, etc.) and tools are being prepared, their completeness and readiness for work are checked.
For the installation of scaffolding, a planned and compacted site is prepared, from which water drainage should be arranged, or a site with an asphalt concrete surface. If the soil is wet, then tamping is carried out with crushed stone, broken brick, concrete.
In connection (according to the initial data) with a height difference of up to 400 mm, the platform for scaffolding along the facade in axes 1-12 is aligned horizontally in the longitudinal and transverse directions. To equalize the height difference up to 500 mm, standard concrete slabs and boards with a thickness of at least 40-50 mm are used.
In Moscow and the region last years there is an increase in the volume of construction and installation works using scaffolding, which is due to their small share of the cost in the total cost of the building and the availability of cheap labor.
Scaffolding is used to accommodate workers, tools and materials in the construction and repair work on the facades of buildings, including during their insulation, finishing, and installation of facade systems.
Scaffolding is installed on buildings and structures with a variety of architectural and planning and constructive solutions, configuration, height and length.
Scaffolding is indispensable in the cramped conditions of Moscow urban development, where they can be used not only as a universal means of scaffolding, but also as a protective screen.
PPR for scaffolding is an organizational and technological document and is in demand by local state supervision authorities when preparing permits for facade work.
Scaffolding is a spatial multi-tiered and multi-section structure that allows you to organize jobs at height, in various horizontal and vertical surfaces.
At present, rack-mount scaffolding attached to a building or structure is widely used in Moscow and the region.
Rack-mounted scaffolding is used to perform the following work:
1) The device of stone and facing small-sized materials (brick, blocks, slabs, etc.) masonry during the construction of buildings and structures.
2) Repair and reconstruction of building facades, including replacement window frames, insulation device.
3) Plastering, painting and other facade finishing works.
Attached scaffolding is attached to the facade of the building with plugs (dowels) of various systems.
Scaffolding consists of steel pipes: vertical posts, horizontal longitudinal crossbars, transverse and diagonal braces (braces), which determine the rigidity of the spatial structure.
Scaffolding structures - inventory, lightweight, collapsible, reusable. The turnover of scaffolding is at least 60 times, and the service life is at least 5 years.
According to the degree of prefabrication, that is, the reduction of labor intensity and the time of installation and dismantling, the attached rack scaffolding can be made and assembled from single tubular, flat frame or volumetric frame elements.
According to the design of nodal connections (during installation and dismantling), rack-mounted tubular scaffolding is divided into types: connected with bolted or wedge clamps and connected with hook or wedge clamps. Racks, frame frame elements are joined using nozzles.
On crossbars or on cross-braces, perpendicular (parallel) to the wall, a panel board is laid wood flooring.
Ladders for climbing to the tiers are suspended from the cross braces and rest on the flooring boards.
Rack scaffolding is installed on the support shoes. The load of scaffolding is transferred to the shoes and then through wooden linings to the ground.
Scaffolding is equipped with safety equipment. To prevent people and objects from falling from a height, fences are arranged, and lightning rods and grounding are used to protect against atmospheric discharges.
Scaffolding is installed on a planned and compacted soil surface, with a drainage device.
Under the shoes of each pair of racks, linings from a board with a thickness of at least 50 mm are laid in the transverse direction. The lining should be horizontal, but without the help of bricks, stones and scraps of boards.
The scaffolding is equipped with adjustable screw supports to ensure horizontality. The horizontality of scaffolding can be provided by the device of a special temporary support structure. Vertical elements of scaffolding (racks and frames) are installed according to a plumb line, and horizontal elements (ties and flooring) - according to the level. When building racks and frames from pipes on nozzles, the gap between pipes and nozzles should not exceed 3 mm. When installing hollow (tubular) structures, it is necessary to take measures against the ingress and accumulation of water in them.
Scaffolding installed near the driveway Vehicle, fenced off with fender bars so that they are at a distance of at least 0.6 meters from the dimensions of the vehicle.
When laying wooden flooring, the strength of the fixing and the absence of the possibility of shift are checked. The gaps between the flooring boards take no more than 5 mm. The protrusions of the boards beyond the surface of the shield should not exceed 3 mm. The flooring boards can be overlapped along the length, the joints are placed on the support and overlap it by at least 200 mm in each direction, while the thresholds are beveled (from a straight line to an angle of 30 degrees). The flooring must be equipped with a side railing with a height of at least 150 mm.
Scaffolding must be equipped with a fence with a railing height of at least 1.1 m, the fence must have an intermediate horizontal support or mesh.
The places of attachment of scaffolding to the facade of the building are indicated in the PPR. As a rule, fastening is carried out with anchors (dowels) at least through one tier for the extreme racks, through two spans for the upper tier and one fastening every 50 square meters projections of the scaffolding surface onto the facade of the building. When the attachment points coincide with the openings of the building (windows, stained-glass windows, etc.), scaffolding is attached to load-bearing structures(walls, columns, ceilings) from the inside of the building using various devices and devices. Scaffolding should not be attached to balconies, cornices and parapets.
The gap between the wall of the building and the flooring is set no more than 50 mm for stone and 150 mm for finishing works. Scaffolding is equipped with ladders with non-slip supports for moving workers between tiers. Stairs are installed at an angle of 70-75 degrees to the horizon.
Scaffolding must be equipped with lightning protection. The grounding resistance of scaffolding should be no more than 15 ohms. During the installation and dismantling of scaffolding, electrical wires located closer than 5 meters from the scaffolding must be de-energized.
During thunderstorms and winds with a force of more than 6 points, the installation and dismantling of scaffolding is prohibited.
Scaffolding is allowed for operation after testing. When testing scaffolding with a standard load, their strength and stability, the reliability of flooring and fences, and grounding are evaluated.
Scaffolding must be under control load for at least 2 hours. The railing of the fence must withstand a concentrated static load of 70 kgf applied in the middle. All load-bearing horizontal ties must withstand a concentrated static load of 130 kgf applied in the middle.
Dismantling of scaffolding is carried out in the reverse order of installation. The descent of the dismantled parts is carried out by a crane or with the help of lifting devices.
During the dismantling of scaffolding, all doorways of the first floor and exits to the balconies of all floors must be closed.
PPR on forests in difficult conditions
Difficult conditions mean:
1) Installation of scaffolding during the construction of high-rise (from 30 floors and above) monolithic residential and public buildings;
2) Installation of scaffolding during the construction or repair of facades of buildings that have a complex shape in plan (polygonal, oval and other complex outlines of the outer walls of the building in plan);
3) Installation of scaffolding on buildings with protruding elements (canopies, overhanging parts, balconies, loggias, etc.).
In Moscow, the volume of construction of high-rise buildings is growing every year. Also, buildings in the plan can have a complex shape with rectangular and oval outlines. Often, window and other openings in these buildings make it possible to mount supporting devices in them for the installation of scaffolding at a height.
Different types of scaffolding allow the use of different schemes for mounting scaffolding on buildings with high heights or with complex wall configurations, as well as other local conditions. For example, clamp scaffolding LRSPH on high-rise buildings is installed using double racks, as a rule, up to a height of 80 meters, and higher (up to 160 meters) - single. The distance between the double posts is taken as a rule 300 mm. The installation of scaffolding tiers is carried out in the usual way, in accordance with the developed PPR.
Scaffolding is fastened to the building using factory-made metal plugs or polymer dowels, as well as through openings (window, door, balcony). When the place of attachment of the scaffolding to the building falls into the opening, the attachment is carried out using an inventory device. Inventory fastening of scaffolding in the window opening of a building is made, as a rule, from the same tubular elements as the scaffolding. Elongated cross-links of scaffolding lead into the opening, then longitudinal pipes are laid on them close to the wall. Fastening of connections and pipes is carried out using clamps or in another way.
If the complex configuration of the walls of the building does not allow the use of the usual scheme of mounting scaffolding with the support of shoes on the ground, then the scaffolding can be installed on support devices at a height. Supporting devices are mounted on the ceiling using cantilever beams or on the wall using brackets. The beams are laid on the ceiling through sheet metal linings so that the length of their cantilever part allows you to install scaffolding at a distance of 600 mm from the wall to the axis of the internal rack. Then, racks with a screw mechanism are installed on opposite ends of the beams. The upper supports of the racks with wooden spacers lead to the ceiling. With the help of screw mechanisms with a tightening torque of at least 5 kgf * m, the racks abut against the floor and beams, pressing them against the floor and fixing the support device in the opening. To fix the scaffolding on the supporting device, loops welded to the beams are used. Metal channels can be used as cantilever beams on the basis of calculations in the PPR for the installation of scaffolding. Telescopic mounting posts with a screw mechanism for adjusting the height of the supports can be used as spacer posts.
Another variant of the cantilever installation of scaffolding at a height (without supporting the shoes on the ground) is the use of a support device mounted on a reinforced concrete wall using a special bracket. To install the bracket in a reinforced concrete wall, a hole is made into which a stud is installed. A rack is hung on the stud, having an eyelet at the top and bottom for hinged fastening on the studs of the brace and beam. Standard shoes are welded to the beam, into which scaffold racks are inserted and scaffolding is mounted. The details of the bracket are made from rolled steel profiles depending on the load of the scaffolding. The point of attachment of the brace on the beam, from the condition of equality of bending moments (economical section of the beam and the smallest weight) should be at a distance of 4/5 of the length of the beam from the wall. The stud for fastening the bracket to the wall is usually used at least M18. Studs in the hinges of the bracket can be structurally the same with a diameter in the unthreaded section of at least 28 mm. Each bracket, as a rule, can withstand a load from two racks of scaffolding of at least 2400 kgf.
When installing scaffolding on a building with balconies (loggias), the installation scheme is used, taking into account the ledge of the building wall. The outrigger is arranged on the scaffolding with the help of diagonal rods. Installation of scaffolding in this case is usually carried out using at least three diagonal rods. Bolt clamps are used as nodal connections during installation. Racks are joined using branch pipes. On the crossbars (or cross braces) perpendicular (parallel) to the wall, a shield wooden flooring is laid. The strength and stability of scaffolding in this scheme is ensured when the installation rules are followed in accordance with the PPR and must be maintained during the operation of the scaffolding. Under these conditions, there are no horizontal components from the load on the scaffolding, forces of scaffolding separation from the wall do not arise. In order to increase the stability of the scaffolding (unloading the scaffold attachment point to the wall), the shoe with the rack is loaded foundation block FBS type.
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