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METHODOLOGICAL DOCUMENTATION IN CONSTRUCTION

TsNIIOMTP

SCAFFOLDING. INSTALLATION, CALCULATION, OPERATION

MDS 12-25.2006

Moscow 2006

The methodological document contains information about scaffolding (types, designs, technical capabilities and production of scaffolding) necessary for their selection and use in construction In fact, simplified methods of testing tests are outlined couple of scaffolds for strength and stability in the conditions of specific construction sites, recommendations are provided for installation and testing, repair and safe operation forests

DEVELOPED by the Central Research and Design and Experimental Institute of Organization, Mechanics tion and technical assistance to construction (TsNIIOMTP) (kantechnical data sciences V.P. Volodin, Yu.L. Korytov).

The methodological document is intended for construction organizations that use scaffolding in the construction of buildings and weapons, as well as for finishing and repair work on the facades.

INTRODUCTION

Scaffolding is classified as scaffolding. Scaffolding is used to accommodate workers, tools and materials for construction and repair work at height.

Currently, the use of scaffolding is expanding, which is increasingcaught by the small share of the cost of scaffolding in the total cost of the building (up to 3% of the cost of a residential building) and the availability of cheap labor.

Scaffolding is a universal means of scaffolding:they are applicable for buildings and structures with a variety of structural, architectural and planning parameters, configuration, height and length. Scaffolding is indispensable in cramped urban conditions, where they are used not only for their intended purpose, but also as protective screens.

The assessment and selection of forests is made according to technical characteristics and technical and economic indicators.

The main technical characteristics are the maximum height of the scaffolding and the standard surface load.

The main technical and economic indicators are: the number of mounting elements and the largest weight of the mounting element, consumption of metal and wood products, cost, labor intensity of manufacturing and complexity of installation 1 m 2 of scaffolding. In addition, when analyzing and selecting forests, it is taken into account quality of accompanying design and operational documentation (working drawings according to ESKD, technical specifications, installation and operating instructions).

1 AREA OF USE

This methodological document is distributedextends to attached, mounted, suspension free-standing and free-standing scaffolding used for construction of residential, public and industrial buildings.

2. REGULATORY DOCUMENTS

SNiP 12-03-2001 Labor safety in constructiongovernment Part 1. General requirements

SNiP 12-04-2002 Labor safety in constructiongovernment Part 2. Construction production

SNiP II-23-81* Steel structures

GOST 9.032-74 * ESZKS. Paint and varnish coatings. Groups, technical requirements and designations

GOST 9.104-79* ESZKS. Paint and varnish coatings. Operating conditions group

GOST 12.4.026-76* SSBT. Signal colors and safety signs

GOST 380-94 Normal carbon steelquality. Stamps

GOST 3242-79 Welded joints. Metoquality control

GOST 3262-75* Steel water and gas pipesrelated. Specifications

GOST 8240-89 Steel channels burninghammered. Assortment

GOST 8486-86* Coniferous lumberbreeds Specifications

GOST 8509-93 Hot steel anglesmelted equal flanks. Assortment

GOST 9467-75* Electrodesarc welding of structural and heat-resistant steels. Types

GOST 10704-91 Steel electrical pipesstraight-seam welded. Assortment

GOST 15150-69* Machines, instruments, etc.gye technical products. Performances for times personal climatic regions. Categories, us conditions of operation, storage and transportation in terms of the impact of climatic factors external environment coated metal for manual

GOST 24258-88 Scaffolding means.General technical conditions

GOST 26887-86 Platforms and stairs forconstruction and installation works. General technical what conditions

GOST 27321-87 Rack-mounted attached scaffoldingfor construction and installation work. Technical conditions

Instructions for using wall-mounted monksscaffolding for work on facadesbuildings under construction. - M.: TsNIIOMTP, 1998.

3. TECHNICAL CAPABILITIES OF SCAFFOLDING

3.1. Forests represent spatiala new multi-tiered and multi-sectional design that allows you to organize workplaces at height, in various horizontal and vertical surfaces.

Currently, rack-mounted attached to the building under construction and freedoms standing, mounted and suspended forests. The most widely used are rack-mounted attached and suspended scaffolding.

3.2. Attached scaffolding is attached to the wall of the building with plugs (dowels) of various systems.

Hanging single-tier (two-tier) scaffoldingare hung with brackets into the openings of the building and secured different ways for building elements (walls, ceilings, columns).

Hanging scaffolding is suspended on strings(cables) to brackets fixed to the building.

The sustainability of free-standing forests is assuredbaked with struts or stretch marks.

3.3. Rack-mounted scaffolding consists of steel pipes: vertical (racks), horizontaltal longitudinal (crossbars), transverse and diagonal connections (braces) that determine rigidity of the spatial structure.

Scaffolding structures - inventory, lightweight,collapsible, reusable.

The turnover of forests is at least60 times, and the service life is at least 5 years.

3.4. According to the degree of assembly, i.e. reductions labor intensity and time of installation and dismantling lady, rack scaffolding can be manufactured and assembled from single (tubular), flat (frames) ny) or volumetric (frame) elements.

According to the design of the node connections (with installation and dismantling) rack-mounted tubular scaffolding are divided into types: connecting with using bolted or wedge clamps and connected using hook or wedge pins. Racks, frame and frame elements are joined using pipes.

3.5. A wooden panel flooring is laid on the crossbars (or cross braces) perpendicularly (parallel) to the wall.

Ladders for climbing to tiers are suspended from cross braces and supported on flooring panels.

Rack scaffolding is installed on supportingki and then using wooden pads on the ground.

3.6. Scaffolding is equipped with safety equipment. To prevent people and objects from falling from a height, fences are installed, and to protect against atmospheric discharges, lightning rods and grounding are installed. General form one hundred end-mounted frame scaffolding, for example type ARIS-200, shown at.

3.7. Free-standing scaffolding is installed asusually from volumetric (frame) elements with a plan size of 1×1; 1x2; 2×2 m, made poured from steel pipes. Frame elements you are joined using pipes. According to another according to the parameters of the free-standing design scaffolding is similar to the design of attached scaffolding owls Unlike attached ones, free-standing forests have their own resilience.

1 - frame with ladder; 2 - frame; 3 - diagonal tie; 4 and 5 - fencing ties; 6- flooring; 7 - plug (or hookwith bushing); 8 - screed; 9 - support; 10 - screw support

Figure 1 - Rack-mounted attached scaffolding

3.8. Canopy scaffolding is a framewith supports for fastening to building elements. Working and intermediate floorings are laid on the frame. Climbing to intermediate style - up the stairs. The fence represents is a spatial frame welded structure made of channels and angles. From outside On the other side of the scaffolding, a protective barrier is installed metal mesh. On top of scaffolding to protect against In case of bad weather, a canopy is constructed from a solid profiled sheet. To lift the scaffolding by crane, sling loops are provided. The general view of single-tier and two-tier scaffolding, for example, the TsNIIOMTP structure, is shown in Figures 2 and 3.

1 - frame; 2 - support; 3 - flooring; 4 - shield; 5 – mesh; 6 - loop

1 - frame; 2 - shield; 3 - mesh; 4 – loop.

Figure 3 - Two-tier scaffolding

3.9. Below is information that is notare bypassed when choosing forests.

3.9.1. Rack-mounted scaffolding usingare used to perform the following work:

Installation of stone and facing chalkco-dimensional materials (bricks, blocks, slabs, etc.) masonry during the construction of buildings;

repair and reconstruction of facades, including replacement window frames, insulation device;

plastering, painting and other finishing works new works.

Standard surface load is regulated up to 500 kgf/m2 according to GOST 27321-87, usually - 200 kgf/m2, for masonry - 250-300 kgf/m2.

The height of scaffolding for finishing and other works on facades ranges from 16 to 100 m, and for masonry - up to 60 m and is determined by the number of tiers supplied, the height of which is usually 2 m. Poppy The maximum permissible height of scaffolding is indicated in GOST 27321-87: for clamps - 100 m, for pieces roaring - 80 m.

The length of the scaffolding (from 9 to 40 m) depends on the number of sections supplied, the length of which is usually set to 2; 2.5 and 3 m. For masonry, the length of the section can be adjusted available 1.5 and 2 m. Length of supplied scaffolding with usually agreed with the customer.

The width of the section (passage between the posts) is taken to be at least 1 m GOST 27321-87, most often 1.25 and 1.4 m, less often - 1.5 and 1.65 m; flooring made of wooden panels can protrude beyond the racks up to 150 mm.

The distance between the scaffolding and the wall of the building to which the rack scaffolding is attached does not exceed varies 150-300 mm, but in necessary cases can be increased to 500 mm.

The points for attaching the scaffold posts to the wall are usually located across the tier, in a checkerboard pattern. ok. In special cases, race attachment points rely on racks in each tier.

3.9.2. Free standing scaffolding is applied for special work in construction, for example measures for thermal insulation on high horizontal pipelines and, in addition, can be used as protective screen, power frame, construction tower, temporary platform, etc.

The standard surface load is assigned to no more than 200 kgf/m2.

The height of the forests does not exceed 14-20 m.

The width of the scaffolding to increase the supporting surface is taken to be at least 2 m.

3.9.3. Canopy scaffolding used for the same work as attached ones, but on facades property of monolithic buildings is increased number of floors (up to 100 m in height). Can be also used for work on large-panel buildings with load-bearing external walls and frame buildings.

250-300 kgf/m 2, load capacity - up to 3000 kgf,and the carrying capacity of each tier is twoRussian forests - no more than 1500 kgf.

Overall height of single-tier scaffolding - up to4 m, two-tier - up to 7 m.

The dimensions of the working area are usually no more thanembroidered 3 m in length and 2 m in width.

The weight of single-tier scaffolding is 1200-1300 kgf.

4. MANUFACTURE AND REPAIR OF SCAFFOLDING

4.1. Scaffolds are produced in climatic conditions designed for areas with moderate climates Tom or for the northern regions according toGOST 15150-69*.

4.2. Attached scaffolding is made from steel pipes with a diameter of 25 to 60 mm and thickness wall thickness from 1.8 to 4.0 mm GOST 3262-75* And GOST 10704-91.

The most used pipes according to GOST 3262-75*are given in the table

Table 1.

For the manufacture of free-standing and suspended scaffolding, not only the mentionedpipes, but also steel profiles, for example profile corners from No. 5 to No. 8GOST 8509-93 or channels from No. 12 to No. 16 GOST 8240-89.

For pipes and steel profiles all carbon steel of ordinary quality, for example St.3sp5 and St.3ps6 GOST 380-94.

4.3. Scaffolding is usually supplied comp. lecture. The kit includes components, not required for installation, and operational documentation (passport, installation and operating instructions).

The manufacturer can supply scaffolding without flooring. In this case, the flooring is made organization that exploits forests.

Wooden flooring panels are made made from spruce or pine boardsGOST 8486-86*The wood is impregnated with an antiseptic and fire retardants.

4.4. During the exploitation of forests, accumulation defects appear: the paint coating is destroyedcovering, corrosion of metal surfaces increasessurfaces, deflections of individual hundred frames and crossbars, bends in the railings of fences, local deformations (dents, cavities, delaminations, tears), cracks in scaffolding elements, etc. Scaffolding repair consists of eliminating these defects.

4.5. Repairs are carried out usingpossibilities of blanks, materials and kitsthose who wereused for preparing forests. Replacements are made preferablystrictly in agreement with the manufacturer. Technical requirements to materials andcomponents must be regulated we have standards (technical specifications).

When repairing, one should not violate the principleinterchangeability of parts.

4.6. Deflections of posts and links are less than 1.5 mm per 1m length can be cold straightened editing. With more significant deflections, with p penetrating corrosion, strut cracks and connections must be replaced. Pipes used for This must be straight and without threads.

4.7. Welding work is carried out by diplomaqualified welders. Welding is performed with calcined electrodes, usually type E 42 GOST 9467-75*. Seam sizesare made according to repair drawings or by analogy with those available that have passed the control inspection. The area of ​​the parts to be welded is cleaned to a metallic shine. SvarochThe seam is cleaned of slag, splashes and drips metal The quality of welds is checked visually in accordance with GOST 3242-79.

4.8. The paint coating is restored by painting in signal colors (yellow, orangegreen, red) according to GOST 12.4.026-76*. In this case, according to operating conditions, group Zh2 according to GOST 9.104-79* is accepted.

5. TEST CALCULATION OF SCAFFOLDING

5.1. Calculation of rack scaffolding produced at strength and stability.

When designing, the scaffolding is calculated for the standard uniformly distributed load on the deck [ q ], which indicated in the technical specifications owls and GOST 27321-87 accepted for rack-mounted scaffolding: clamp - 100, 200, 250 and pin - 300 and up to 500 kgf/m 2. It is taken into account that the average load is 250 kgf/m2 for stone work and up to 200 kgf/m2 for finishing and other works. Cro In addition, the longitudinal connections of the scaffolding are designed for a concentrated load of 130 kgf applied in the middle.

The need for a verification calculation of fussdepends on the selection of scaffolding for specific construction work, as well as at the stage of their use in construction site to assess the safety of work under real load.

When choosing scaffolding, the calculation consists ofdividing the actual uniformly distributed load on the deck q and comparing it with the normative [ q ], specified in the technical specifications.

The load on the deck is determined by the product [ q] to the flooring area. In this case, the structure of the flooring must be provided withjoint work of flooring boards (boards).

When using scaffolding, calculate the most loaded parts of the scaffolding are scattered - longitudinal braces and racks, flooring, as well as a scaffolding attachment to the wall.

With this calculation, it is allowed for the stock strength consider the work of flooring boards local.

Figure 4 shows a typical design diagram of scaffolding, which shows three sections of length L and width at this is applied to the least advantageous pointke O in section 2-3. With transverse flooring P transmitted to two longitudinal connections at points determined

Figure 4 - Calculation diagram of rack attached scaffolding

Load RB is not required to be determined, so as it is obviously less than P A, due to the factwhat is known from practice: e 1 > e 2= (30-40) cm.

Maximum (excluding compensatingth) bending moment in the longitudinal connection, kgf cm:

In a number of scaffolding structures (clamps, piecesrevy) this load is not transmitted in the center of the rack, but with an eccentricity e, the value of which does not exceed 40-70 mm. Because of this, a maximum bending moment may occur in the rack, kgf-cm:

5.1.2. Checking the racks

Checking the strength of the racks

The greatest stress in the inner strut from longitudinal compression and bending moment is determined, kgf/cm 2:

Where R p

F- cross-sectional area of ​​the rack pipe with external ( D) and internal ( d) diameters, cm 2. Effective bending stresses at the highest more loaded horizontal connections and stands ke according to paragraphs 5.1.1 and 5.1.2 are compared with the permissible voltage, which, for example, for steel pipes St. 3GOST 380-94 accepted [s ] = 2100 kgf/cm2.

Checking the stability of the racks

The stability of the racks is checked under a combination of unfavorable conditions: without taking into account the elastic support from horizontal connections, at a maximum and eccentrically applied load R P, with a stand height h equal to standing between the scaffolding fastenings to the wall.

The calculation of the stability of the rack from P p is carried out according toSNiP II-23-81* according to the formula

Where φ e= 0.1-0.4 - coefficient of reduction in design resistance during eccentric compression;

γ s= 0.95 - coefficient of operating conditions for compressed scaffolding posts.

The coefficient φ e is determined from the table below depending on the conditional flexibility γ y and the given relative eccentricity m ef, determined by the formula

Where η = 1-1.1 - coefficient of influence of the section shape;

m= e F/W- relative eccentricity.

In existing scaffolding structures, the eccentricity e= 4-7 cm. For pipes of racks with a diameter of 42-48 mm, the coefficient η = 1 can be taken, and then the coefficient m e f, is in the range from 0.158 to 0.096.

Conditional flexibilityλ y determined by the formula

Where λ = μ e/ i- stand flexibility;

μ =1-1.1 - coefficient depending on the method of fastening the racks; for most there is existing designs can can be taken equal to one.

For existing structures forests in a simplified calculation can be taken

λ y = 0.03 λ

Coefficient φ e depending on theλ y and m ef is found according to table 74SNiP II-23-81*, fragment which is shown in Table 2.

Table 2.

5.1.3. Checking the flooring

The greatest stress in the flooring from bend in the section passing through point O in flooring board, determined, kgf/cm 2:

Where W H= b t 2 /6 - moment of resistance dos ki, cm 3;

b- board width, cm;

t - board thickness, cm.

Flooring boards are manufactured according toGOST 8486-86*, as a rule, from pine with permissible voltage bending [s s] = 150 kgf/cm2.

In case of flooring repairs and usenon-standard boards the permissible voltage is accepted [s s ] = 100 kgf/cm 2 .

5.1.4. Checking the scaffolding to the wall

Checking the main fastening parameters are determined by the force of pulling out the dowel (not longer than less L = 10 cm) from wall Q, equal to the friction force, and the torque Mcr of tightening nut 1, according to the design diagram on.

Pull force Q determined, kgf:

Where f - friction coefficient of steel according tobrickwork (0.35) or concrete (0.4);

z = 2-3 - the number of petals 2, pressed against the wall with a cone nut 3;

N=s C.M. de, kgf, - simplified calculation is acceptablemy pressure force of the petal on the wall from the conditions of strengthtype of wall material in compression;

s cm- lowest limit firmlytype of wall material (s cm = 50 kgf/cm 2 - sand-lime brick,s cm = 80 kgf/cm 2 - concrete);

d, cm, is the outer diameter of the petal;

e,cm, - length of contact of the petal to Wall.

The optimal torque on the nut required to securely fasten the dowel and not crush the wall material is determined, kgf cm:

Where S, mm, - propeller pitch;

R- friction angle, which is determined from the expression

Where fR= 0.2-0.28 - friction coefficient in the screw-nut pair;

R= 30°-32° - half the screw profile angle.

Figure 5 - Design diagram for attaching rack-mounted scaffolding to the wall

5.1.5. Calculation example

The following initial data were accepted:

main scaffolding sizes: L = 200 cm, e= 100 cm, e 2= 30 cm, h = 200 cm;

longitudinal connection - from a pipe 42.3 × 3.2 m; W = 3.6 cm 2 ;

stand - made of pipe 48×3.5 m; F = 5 cm 2, W = 5.44 cm 2, I = 1.57 cm, e= 7 cm;

pipe material - steel St. 3,GOST 380-94, [ s ] = 2100 kgf/cm 2 , E = 2-10 6 kgf/cm 2 .

Loads: dispersed q = 200 kgf/m2, reduced P - 200 kgf, maximum per stand ku R p = 1200 kgf.

Checking the longitudinal connection according to (1) is equal to:

R A = 200 70/100 = 140 kgf.

Maximum bending moment in longitudinal connection according to (2)

M max = 140/2 200/2= 7000 kgf cm.

According to formula (4)

s ps = 7000/3.6 = 1944 kgf/cm2.

The strength of the longitudinal connection is ensured, since

s ps = 1944 < [ s ]= 2100 kgf/cm2.

Checking the rack

Maximum bending moment at standstill ke according to (3) is equal to:

M max = 140 7 = 980 kgf cm.

Highest voltage according to (5)

s Sun = 1200/5 + 980/5.44 = 240 + 180 = 420 kgf/cm 2,

which is less [ s ] = 2100 kgf/cm 2, i.e. the strength of the rack is ensured.

Checking the stability of the rack

The flexibility of the rack is:λ = 1,200/1.57 = 127.

Conditional flexibility according to (8)

Relative eccentricity m = 7 5/5.44 = 6.4.

The reduced relative eccentricity is e/ = 1.05 6.4 = 7.0.

According to table 2 with valuesλ y = 4.1 and m ef = 7 φ e ~ 0.13.

Stability of the rack according to (6) is ensured:

1200/0,13 5 = 1846 < 0,95 = 1995 кгс/см 2 .

Checking the flooring

Moment of resistance of a pine board GOST 8486-86*, for example with dimensions b = 50 cm and t = 2 cm, equal to:

W H = 50 2 2 /6 = 33.3 cm 3.

Maximum voltage according to (9)

s n = 140 30/33.3 = 126 kgf/cm 2< [ s s] = 150 kgf/cm 2,

those. the strength of the flooring is ensured.

Checking the scaffolding to the wall

Dowel pressure force at dimensions d = 3 cm, e= 4 cm on a sand-lime brick wall (s cm = 50 kgf/cm 2)

N = 50 3 4 = 600 kgf.

The force of pulling a dowel with two petals out of the wall, with the coefficient of friction f = 0.35 according to (10) is equal to:

Q = 0.35 2 600 = 420 kgf.

Parameters α are determined by (12) and p by (13) medium diameter screws d =10.8 mm, step S = 1.75 mm, half the profile angle screw (β = 30° and friction coefficient f p = 0.25:

α = arc tg (1.75/3.14·10.8) = 2°56";

R = arc tan (0.25/cos 30°) = 16°4".

The optimal torque on the 5 cm screw nut according to (11) is equal to:

M cr = 420 10.8/2 tg (2°56" + 16°4") = 84 kgf cm.

With a screw handle length of 10 cm, the force does not exceed 9 kgf, which is quite acceptable.

Ras even confirms the correctness of the choice of parameters ditch for dowel fastening of scaffolding to the wall.

5.2. Calculation of suspended scaffolding produced at the strength of attachment to the building and the strength of the frame from the load and its own weight.

The calculation diagram is shown in

Scaffolding is hung behind the wall opening at points A And IN and rest on the wall at a point D.

The strength of the wall in the opening is checked for a load equal toR A And RB, and

R a =R D =Pe /h,

R B= P

Where R- load on the scaffolding, attached on distance e from the wall;

h - the distance between the load-bearing crossbars of the scaffolding.

Figure 6 - Design diagram of suspended scaffolding

The bending strength of the frame is checked in sections passing at points B And G. From the diagram it can be seen that the corresponding bending moments are determined by:

M b =R a a;M D =R B

Effective and permissible stresses are defined similarly to those described above for rack scaffolding.

6. INSTALLATION AND TESTING OF SCAFFOLDING

6.1. Rack scaffolding installed on a planned compacted soil surfaceone equipped with drainage.

Under the shoes of each pair of racks there areweave a lining in the transverse direction from boards with a thickness of at least 50 mm. It should be ensuredbake the lining horizontally, but without relics of bricks, stones and scraps of boards.

The scaffolding is equipped with adjustable screwswith supports to ensure horizontal tee. The horizontality of the forests can be ensured This was accomplished by installing a special temporary support structure.

6.1.1. Vertical elements of scaffolding (racks and frames) are installed using a plummet gauge, and horizontal elements (braces and flooring) are installed using a level gauge.

When building racks and frames from pipes onto pipes, the gap between the pipes and pipes should not exceed 3 mm.

When installing hollow (box-shaped, tubular) structures, measures are taken to prevent water from entering and accumulating in them.

6.1.2. Forests located near the passage vehicles are protected with fender bars so that they are located at a distance of no closer than 0.6 m from the vehicle’s overall dimensions.

6.1.3. When laying the flooring, check the strength of the fastening and the absence of possible shifts. Gaps between deck boardsaccept no more than 5 mm. The protrusions of the boards behind The surface of the shield should not exceed 3 mm. Flooring panels can be connected along the length overlapped, the joints are placed on a support and not cover it by at least 200 mm in each side, the thresholds are beveled (from straight possible - up to an angle of 30°). The flooring must be worn tripled with a side fence at least 150 mm high.

6.1.4. The scaffolding is equipped with a fence with a high If the railing is at least 1.1 m, the fence must have an intermediate horizontal support or mesh.

The places where the scaffolding is attached to the wall are indicated in the work plan.

In the absence of instructions, fastening scaffolding to load-bearing wall buildings with anchors (dowels) produced in at least one tier for extreme racks, two spans for the top tiers and one fastening for every 50 m 2 about projections of the scaffolding surface onto the façade of the building. At coincidence of fastening points with openings in the wall scaffolding is attached to load-bearing structures(walls, columns, ceilings) with inside buildings using various devices and devices.

Scaffolding should not be attached to balconies, cornices, or parapets.

6.1.5. The gap between the building wall and the flooring is set to no more than 50 mm for stone and 150 mm for finishing works Oh.

6.1.6. Scaffolding must be equipped with a ladderprone with non-slip supports for the feet movement of workers between tiers. Stairs of a hundredhang in working position at an angle of 70-75° tohorizon. The design of the stairs should be suitable let createrequirements GOST 26887-86.

6.1.7. Forests must be equipped withlack of protection.

The scaffolding grounding resistance should be no more than 15 Ohms.

During the installation and dismantling of electrical scaffoldingelectrical wires located closer than 5 m from the scaffolding are de-energized.

During a thunderstorm and wind force of more than 6 pointsScaffolding is not installed or dismantled.

6.1.8. Forests are allowed to be used aftertests. When testing scaffolding to standard load, their strength and stability, the reliability of the flooring and fences are assessed,

grounding. Forests must be under controlroll load for at least 2 hours.

6.1.9. The fence railings must withstand apply a concentrated static load of 70 kgf applied to them in the middle and perpendicularly.

All load-bearing horizontal connections must we can withstand concentrated static load 130 kgf applied in the middle.

6.1.10. Scaffolding is dismantled in the village research, the opposite of montage. Descent de assembled parts are carried out by crane or using lifting devices.

During scaffolding dismantling, all doorways on the first floor and exits to balconies on all floors must be closed.

6.2. Canopy scaffolding mounted usinglifting cranes (tower, jib)with slinging like a regular two-way ropewith a webbing sling, and with the help of specialtraverse.

6.2.1. When installing scaffolding on a monolithic ora brick building must have openings in the wall measuring 200-300 mm into which support brackets are installed,fixed with wooden wedges. One of the options for attaching scaffolding to the wall is shown in Figure 7.

For panel or frame buildings Scaffolding is installed by hanging it on horizontal load-bearing elements(crossbars, lintels, etc.).

6.2.2. Walls in which openings are made must be checked for load from scaffolding according to the diagram in Figure 6, taking into account their load materials, tools and workers agree but the work production project.

6.2.3. Testing of suspended scaffolding before extrusionoperation is carried out in the same manner, as well as attached scaffolding. Canopy scaffolding should be under a control load twice the nominal load for at least 15 minutes.

1- wooden wedge; 2- scaffolding bracket; 3- wall.

Figure 7. – Mounting point for hanging scaffolding to the wall.

7. ENSURING SAFETY WHEN OPERATING FORESTS

7.1. Commissioning of scaffolding is allowed after acceptance by a commission appointed by the head of the construction organization, and is registered in the accounting journal according to GOST 26887-86.

If the scaffolding has not been used for a month, then it is allowed to be used after acceptance by the mentioned commission.

Forests should be operated in accordance withwith manufacturer's instructions and requirements SNiP 12-03-2001.

7.2. Technical condition of forests control is checked before each shift and periodically inspections every 10 days. Resultyou mention periodic inspections chickpea magazine.

The strength and reliability of the crepe is checkedlines, floorings, fences, fixing devices protecting detachable connections concerns from spontaneous separation, condition of welds, deflections of racks and crossbars.

Before the start of the shift, the flooring is cleared of snow and ice.

After the end of the shift, the flooring is cleaned from debris and remnants of construction materials.

7.3. Forests are subject to additional inspection ru after rain or thaw, which may reduce the bearing capacity of the foundationthem, as well as after mechanical influences. In case of deformation, the scaffolding must be repaired and accepted by the commission again.

7.4. Workers must be familiar with rules for working on scaffolding, with load diagrams containing information about permissible loads zakh and the order of their placement.

Arrangements should be made to ensure the safe disembarkation of persons from the work area.hundredin the event of an emergency.

7.5. If there are people or trans port near scaffolding and when performing work at a height of 6 m or more, there must be at least two floorings: working (upper) and protective (lower).

The workplace on the scaffolding must be protected from above by a flooring located at yourplace no more than 2 m from the working floor.

Installed above the entrances and entrances of buildingsThe protective visor is leaking.

7.6. Supply of materials to scaffolding produces using cranes (winches) from above, also through windows and other openings in the wall of the building.

If the scaffolding is located in the crane's operating area, then the crane's operations, for example, lifting a load and turning the boom, are not combined.

The load is moved by a crane above the top pointscaffolding at a height of at least 1 m. The load is lowered by crane onto the flooring at minimum speed, smoothly and without shocks.

7.7. Marking of scaffolding on load-bearing elementstach must be maintained and restored whennecessary throughout the entire service life. The label must contain informationabout the manufacturer, scaffolding designation, batch number and date of manufacture.

8. STORAGE STORAGE

8.1. IN During periods between exploitation, forest storage is organized.

Scaffolding parts are stored in sorted form(posts, crossbars, braces, frames) in a container rah and packages. Small parts (anchors, pipe ki, clamps, etc.) are stored separately in containers.

8.2. Scaffolds should be stored in a closed roomshelter or under a canopy on pads, except anticipating contact with the ground.

Containers, packages and containers can be stacked, but not more than three tiers.

Rack-mounted wedge scaffolding is a universal rigid structure. It is easy to install and dismantle. Can be used multiple times. This type of scaffolding is a frame structure.

Rack-mounted wedge scaffolding is used for construction work outside and inside the building. Also, attached rack scaffolding is used not only in construction work, but also for organizing stages and stands, as well as formwork for buildings and covered pavilions. Wedge rack attached structures are used in the following cases:

• bricklaying and plastering;
• repair of structures utilities and industry;
• support for formwork;
• restoration work.

Certificates of conformity and regulatory documents

This type of scaffolding must meet the requirements of GOST 24258-80. Attached wedge scaffolding must be produced strictly in accordance with the initially approved design documentation.

When producing rack wedge scaffolding, steel pipes are used various diameters and different wall thicknesses. GOST provides for differences between different scaffolding elements in the same structure. In the manufacture of wedge scaffolds of this design, the use of aluminum is not allowed due to the fact that its price is quite high, and difficulties arise during welding; because of this, the scaffold cannot be used repeatedly. Parts of the instructions are coated with a durable powder coating for greater safety.

Along with the fact that wedge rack scaffolding is manufactured according to GOST standards, the design of the scaffolding is developed in accordance with the technical specifications. Besides, scaffolding undergo mandatory certification. Such a procedure is necessary not only for reporting, but also for quality control, both in development and in manufacturing and assembly of the structure. The reliability and strength of the attached wedge rack scaffold is verified by a high load test carried out at the time of certification. Each scaffolding structure has a passport, where absolutely all parts of the structure are registered, which makes pre-construction installation much easier. Using the product passport, you can check the presence of all parts of the structure during installation and dismantling.

Specifications

A jack will be needed to place the verticals on it. Using a jack, you can adjust the level, in other words, the height of the horizontal belts of the scaffolding. This part of the structure must be installed under each vertical part of the scaffolding.

Essential elements

• Thrust bearing needed to place verticals. It should also be under each part of the verticals.
• Start element placed on a footrest. Serves to simplify the scaffolding installation process. This element also carries vertical parts. The starting element also has a flange, which helps to secure it horizontally with other similar parts.
• Vertical stand- This is the main load-bearing element of any type of scaffolding design. It has flanges, which are made in increments of 50 cm or 100 cm. They are secured with flanges by self-braking wedges with horizontals and diagonals. The vertical racks have parameters of 1.5; 2; 3 meters. The vertical stand is made of steel pipe 48 mm in diameter, 2 mm wall width.
• Horizontal connection Available with a locking bracket, which has a self-braking wedge. It is secured with a clamp lock and a wedge to the vertical posts. The horizontal elements are also made of steel pipes, the length of which reaches 3 m, the diameter is 48 mm, the wall width is 3 m. The distance between the vertical posts can be different: 1 meter, 1.2 meters, 1.5 meters, 2 meters, 3 meters.
• Diagonal element necessary for the stability of the scaffold structure. The tiers at the end and at the beginning must have diagonal ties. The diagonal is set so that it tilts in different directions. If the tilt is carried out in different directions, the scaffolding may topple. Diagonal elements have standard parameters: 1×2, 1.2×2, 1.5×2, 2×2, 3×2.
• Flooring is important element scaffolding. It serves to ensure the reliability and safety of forests. It spreads on several tiers. have a width of 45.2 cm. The decks must have guards.
• Wall support necessary in order to attach the scaffolding structure to the wall of the building. When purchasing scaffolding, wall supports are determined by the customer.

Installation and dismantling of wedge rack-mounted scaffolding

Before installing scaffolding, you need to carefully prepare. First of all, an assembly diagram for wedge-mounted scaffolding must be drawn up. Everyone who will work on the scaffolding must be familiar with this diagram and instructed in the work procedure. The site for scaffolding must be planned and prepared: the surface must be leveled, construction and other debris must be removed.

Installation procedure

1. It is necessary to install thrust bearings on the previously prepared surface. Their width must strictly correspond to horizontal connections (1; 1.2; 1.5; 2; 3 meters).
2. The starting elements are put on the thrust bearings themselves.
3. Along the perimeter of the installed starting elements you need to connect them using horizontal connections.
4. It is necessary to install into the existing holes of the vertical elements vertical racks(1.5, 2, 3 meters).
5. Vertical posts are also connected to each other by horizontals.
6. Next, the floorings are laid on the resulting tiers.
7. To give the forest the necessary rigidity, you need to secure the diagonals with the appropriate dimensions.

The scaffolding structure must be attached to the wall using anchors and wall supports. The scaffolding load must also be calculated according to special scheme. Without these manipulations, it is impossible to fully install attached wedge rack scaffolding.

Dismantling is carried out in reverse order, starting from the upper tier of forests. The extension ladder is used taking into account the wishes of the customer.

To ensure safety at a construction site, it is necessary to make special canopies.

Operating rules

Wedge drainage scaffolding can only be used after the installation of the structure has been completed. Acceptance must be carried out by the person responsible for safety precautions at the site.
Upon acceptance, the following is checked: the set level of the scaffolding, the correct assembly of the components, the fastening of the structure to the wall, the presence of canopies and appropriate fences.

1. Every day the master must check the structure before starting work.
2. Ice and snow, as well as construction debris, must be regularly removed from decks.
3. The load on the decking should not exceed those specified in technical passport options.
4. When working with a tower crane when feeding materials to upper tiers scaffolding must take into account safety precautions.
5. Do not lift loads near scaffolding.
6. The operation of the crane must be regulated by a signalman located on the scaffolding.
7. When working with a stationary lift, you need to take into account that it must also be attached to the building itself.
8. When lifting a load, the crane boom must be at least 1 meter above the fence. The load should be lowered onto the decking at the lowest speed.
9. Canopies should be built over the passages between tiers, as well as over the passages.

Mandatory Security Measures

1. The frame of the structure must be secured with brackets. The brackets must not be removed arbitrarily.
   Access by unauthorized people is not allowed to the area of ​​assembly and disassembly of attached wedge rack scaffolding.
   Installation and disassembly of the structure at height must be carried out by workers who have special fastening belts.
2. During the installation of scaffolding, openings and passages on the first floors, as well as balconies, must be closed.
3. Power lines that are located at a distance of up to five meters from the scaffolding structure must be removed or de-energized.
4. Before removing the flooring or moving it from one tier to another, you need to clear it of debris and containers. It is not allowed to dump all this from the scaffolding.
5. Horizontals and verticals that are located near passages must be protected from impacts from vehicles.
   During a thunderstorm or strong wind work on scaffolding, as well as installation and dismantling of scaffolding must be stopped.
   The scaffolding must be grounded to safe work in a thunderstorm.
6. To work at heights exceeding 15 meters, workers with a permit to work at heights must be allowed.
7. The load on the deck should not be higher than that specified in the project.
   Cluster large quantity people are not allowed in one place.

Forests can be transported using any transport that can ensure safe transportation of forests. Structural elements must not be dropped from a height, as this will cause damage. Storage of the disassembled structure should be carried out under a canopy; it is best to use gaskets that prevent the scaffold elements from coming into contact with the ground.

Attached wedge rack scaffolds from trusted manufacturers, as a rule, have a warranty of one year.

GOST 27321-87

INTERSTATE STANDARD

ATTACHED RACK SCAFFOLDINGS FOR
CONSTRUCTION AND INSTALLATION WORK

TECHNICAL CONDITIONS

IPC PUBLISHING HOUSE OF STANDARDS
Moscow

INTERSTATE STANDARD

Date of introduction 01.01.89

This standard applies to rack-mounted attached scaffolding made of steel pipes used in the construction, reconstruction and repair of buildings and structures to accommodate workers and materials directly in the area of ​​construction and installation work.

1. TECHNICAL REQUIREMENTS

1.2.2. The following structure is established for the symbolic designation of forest brands.

Table 1

Dimensions in meters

Example of a symbolrack-mounted attached clamp scaffolding with a standard value of surface load of 2000 Pa and a maximum height of 60 m:

LSPH 2000-60 GOST 27321-87

The same, rack-mounted attached pin scaffolding with a standard surface load of 2500 Pa and a maximum height of 40 m:

LSPSH 2500-40 GOST 27321-87

1.3. Characteristics

table 2

Previously, in more ancient times, for the construction and repair of buildings, disposable scaffolding was used, made of beams and boards, which did not provide the necessary reliability of the system. This is where the general name of the structure came from – scaffolding. Nowadays, several types of prefabricated scaffolding have been developed and are produced by industry, which are characterized by high reliability and ease of use, which can be used repeatedly.

All attached scaffolding is installed near the working wall and must be secured to it using anchors. As a rule, these are self-propping bolts that are placed into holes punched in advance in the wall. Fastenings are installed at the rate of one point per two sections of scaffolding.

Scaffolding catalog

Price: from 140 rub. per sq.m

Price: from 160 rub. per sq.m

Types of attached scaffolding

All types of attached scaffolding are united by the way they are installed near the working wall - they are placed close to the outer or interior wall buildings or structures. Scaffolding varies in the way the elements are connected.

• Attached rack wedge scaffolding ; are highly durable and are often used for masonry work. The connection of structural elements is carried out using a special “wedge-flange” type fastening. The height of the scaffolding is increased as the walls are raised. The scaffolding is securely attached to the wall with brackets along the entire height of the structure.
• Attached rack-mount clamp scaffolding ; used for installation and finishing work, they are considered universal in construction, since they are installed against walls of any configuration. The elements are fastened with clamps.
• Construction frame scaffolding ; used for finishing and repairing large straight sections of walls. The main prefabricated elements are horizontal frames, to which the remaining components of the frame are attached using flag locks fixed on them.
• Attached construction pin scaffolding ; They are used on straight facades, but in combination with clamp scaffolding they are also quite suitable for complex facades. The system is based on pin fasteners, which are located on rack elements. Such scaffolding is attached to the working wall using special hooks.
• Rack-mounted cup-type scaffolding ; they are also called "Cup-Lock", which translated from English means "cup-lock". This spatial design from racks that are connected to each other by crossbars, giving the scaffolding rigidity and stability. Special connections in the form of a cup, placed on the racks and sliding freely along it, make it possible to securely fasten all structural elements. The supports can be either adjustable – for uneven surface, and non-adjustable - they are installed on a flat surface.

Prices for components for scaffolding

Tier pitch, m: 2.0. Frame pitch along the wall, m: 2.3. Passage width, m: 1.1.

Advantages of using scaffolding

Despite the name preserved from ancient times, today scaffolding is made from metal pipes. The big advantage is the relatively low weight of the structure and the speed of assembly and disassembly. The great advantage of attached scaffolding is the possibility of their gradual assembly, moving upward as the wall is laid, or vice versa, the ability to dismantle the upper tiers after a given section of the wall is completed, and the work front gradually moves down.

Scaffolding is an indispensable attribute of construction or facade reconstruction multi-story building. Frame-type structures enjoy well-deserved recognition among builders due to their reliability and ease of assembly. Frame scaffolding is manufactured in a modular design, so that it can be easily modified and expanded as needed.

Design and execution

In many branches of technology, it is generally accepted that simplicity is always a symbol of reliability. Frame scaffolding is extremely simple. They are a horizontal frame made of steel pipes, the rigidity of which is enhanced by ties. Such connections also serve as fencing for personnel working on scaffolding. Individual sections of frame-type scaffolding are connected to each other using locking locks, mostly of the flag type. Naturally, according to its purpose, wooden flooring is provided on each horizontal frame tie. The deck is often equipped with hatches to allow vertical communication between the individual sections.

The reliability of frame scaffolding is ensured by its supports. They can be unregulated, on a regular welded bearing made of thick sheet construction steel. Modern designs are equipped with height-adjustable supports, the main part of which is screw mechanism using thrust thread according to GOST 10177-82 or trapezoidal thread according to GOST 24737-81. Thrust threads are used more often because they allow balancing not only axial, but also radial loads that inevitably arise during the operation of scaffolding.

Classification of frame scaffolding can be made according to the following parameters:

1. By frame type. There are walk-through frames tubular type(the thickness of the pipe wall depends on the height of the scaffolding and the maximum permissible load on it) and frames with stairs designed for the movement of production personnel. In this case, the main ones are the walk-through frames, and the stair frames are designed in the form of inserts located at a certain interval.
2. By type of connections, which can be horizontal and diagonal. Despite some restrictions on the actions of workers, diagonal frames are used more often because they provide increased rigidity and safety.
3. On the execution of fastening scaffolding to the facade of a building or structure. Fastening brackets can be disposable, using massive dowels that are aimed at the surface, or, more often, anchor brackets that can be easily removed when reinstalling the scaffolding to a new place of use.
4. By type of flooring boards. When moving massive loads through forests or construction tools perforated steel flooring is used; in other cases, pine or spruce boards are preferable, without structural defects and with moisture-proof impregnation. Sometimes they are ordered combined types floorings, where wooden elements adjacent to metal ones.

Standard sizes of frame type scaffolding

Frame scaffolding is produced in accordance with technical standards and the requirements of GOST 27321-87, which systematizes the requirements relating to all types of attachments building structures vertical type. This standard contains instructions for the design of all fastening units and connections, as well as requirements for materials. In addition to GOST, manufacturers also develop their own specifications that relate to decking boards, as well as requirements for welded and enclosing elements.

The rational choice of the structures under consideration is determined by the height of the structure, the complexity of the work performed, as well as the calculated values ​​of operational loads. It should be noted that frame scaffolding is used when working on straight facades that do not have protrusions, bends, etc. When choosing, you should pay attention to specifications pipes (the presence of an anti-corrosion or hardening coating, and the method of production - cold-rolled pipes are preferable to hot-rolled or drawn pipes, since they better resist bending and tensile stresses).

The marking of frame-type scaffolding includes the letter abbreviation LRSP (or LSPR), which means (with permutations of individual words) “rack-mounted attached frame scaffolding.” This is followed by a number. It can indicate the maximum axial load on the scaffolding in kilograms (and then it will be three-digit: for example, LRSP-200 allows a load of no more than 200 kg), or it can also indicate the maximum height of the facade to which the structure can be attached (in particular, scaffolding LRSP-60 designed for a height of 60 meters).

Despite the differences in names, all sizes and types of frame scaffolding differ in the standard distance between individual racks (it is 950 mm), which often allows the installation of structures from elements from different manufacturers.

The remaining technical characteristics of scaffolding in the LRSP line are:

• Permissible loads per frame, kg – up to 200 kg (in the presence of reinforcing crossbars, the load can be doubled, as reported in the manufacturer’s instructions);
• Vertical size of each tier, mm – 2000;
• Length of each individual module, mm – 3000 (under individual order it is possible to manufacture modules with a length of 2000 mm);
• Width of each section, mm – 1000;
• Load limit on the frame until its irreversible deformation begins, kg – 600.

The main difference in the design of frame scaffolding is the dimensions (diameter and wall thickness) of the tubular elements. For example, for the production of scaffolding LRSP-30 a pipe of 30×1.5 is used, for LRSP-40 a pipe of 42×1.5 is used, etc. Based on the dimensions of the supporting part, minimum height installation of scaffolding is 2 meters.

How to assemble frame scaffolding?

The sequence of installation of frame-type scaffolding is as follows:

1. The site for installation is being prepared: the soil is planned and leveled, the site is cleared of stones, snow and construction waste, and then dried.
2. When installing newly purchased scaffolding, its completeness and availability of a certificate of conformity are checked.
3. Personnel involved in installation must have permission to carry out the work.
4. Direct installation begins from one of the corners of the building or structure. Wooden shoes with a height of at least 40 mm are installed on the prepared site, on which the supports are mounted. The support spacing should not exceed the values ​​​​established by the scaffolding manufacturer.
5. Adjacent vertical frames of the first tier are mounted on thrust bearings or screw supports and connected with ties. Control of parallelism and perpendicularity of the installation is carried out using a level.
6. All other horizontal modules of the structure are mounted similarly.
7. The tier is anchored or doweled to the wall (the installation step is regulated by the manufacturer’s instructions).
8. The crossbars and decking of the first tier are installed, during which the maximum permissible gaps, shifts and leaks are controlled. Side guards are installed.
9. The next tier is installed in a similar manner, with the stiffening connections being placed in a checkerboard pattern.
10. Check in progress finished design for strength. The flooring and fencing are tested, and the reliability of the closure of the flag connections is monitored.