Scaffolding refers to the various supports erected on the construction site for workers to operate and solve vertical and horizontal transportation. It is mainly for the construction personnel to operate up and down or the perimeter safety net enclosure and high-altitude installation components. There are many types of scaffolding, which can be divided according to the use, framing method, setting form, support method, connection method of scaffolding flat rod and vertical pole, and material.

Introduction to common types of scaffolding for construction projectsThe current main scaffolding classifications include fastener-type steel pipe scaffolding, bowl-type steel pipe scaffolding, portal steel pipe scaffolding, socket-type disc buckle steel pipe support, wood scaffolding, bamboo scaffolding, tool-type scaffolding, hydraulic lifting integral scaffolding, etc.

Fastener type steel pipe scaffolding

Fastener steel pipe scaffold is a kind of multi-pole scaffold widely used at present, which can not only be used as external scaffolding, but also as internal scaffolding, full scaffolding and formwork support. Fastener-type steel pipe scaffolding consists of steel pipes, fasteners, and bases. The steel pipe is a welded steel pipe with an outer diameter of 48mm and a wall thickness of 3.5mm, and the fasteners are malleable cast iron or marble steel fasteners

Bowl buckle steel pipe scaffolding

Bowl buckle steel pipe scaffolding is a versatile tool-type scaffolding. It is composed of three categories: main components, auxiliary components and special components, and the whole series is divided into 23 categories and 53 specifications, which can be used as general single and double row scaffolding and support frame, and can also be used as support columns, material hoisting frames, cantilever scaffolding, climbing scaffolding, etc

Gantry steel pipe scaffolding

Gantry scaffolding, also known as "scaffolding" and "frame scaffolding", is a form of scaffolding that is widely popular in the international civil engineering community. A series of products have been formed, with a complete range of varieties and more than 70 kinds of accessories, which can be erected inside and outside scaffolding, full house red frame, support frame, working platform, well frame, etc

Attached lifting scaffolding

The basic principle of attaching the lifting scaffold is to use the bearing capacity of the concrete that has been poured into the building to fix (attach) the scaffold and the specially designed lifting mechanism on the building structure respectively, when the restraint of the scaffold and the building is untied and fixed on the lifting mechanism when lifting, the lifting of the scaffold is realized through the lifting power equipment, and after the lifting is in place, the scaffold is fixed on the building again, and the constraint of the scaffold and the lifting mechanism is relieved

gantry

The gantry frame is a portal frame composed of columns and wheel beams. Pulleys (sky wheels, ground wheels), guide rails, hanging plates, safety devices, lifting cables, and wind ropes are added to the gantry to form a complete vertical transportation system. The safety device of the gantry frame should include automatic leveling, anti-top (limit position), overload power-off alarm, anti-falling device (broken rope protection), frame body stabilization device (attached wall device, cable wind rope, counterweight).

Socket type disc buckle steel pipe bracket Socket type disc buckle steel pipe bracket is composed of vertical rods, horizontal rods, oblique rods, adjustable bases and adjustable brackets and other structural accessories. The upright rod is connected by casing or connecting rod socket, and the horizontal rod and the oblique rod are snapped into the connecting disc by the rod end buckle joint, and quickly connected with a wedge-shaped bolt to form a steel pipe support with a structural geometric invariant system, which can be divided into two categories according to its use: scaffold and formwork support

Standard practice of scaffolding at the construction site: 1, floor-type external scaffold 1, floor-type external scaffold foundation should be flat and tamped, and a backing plate should be set along the length of the outer scaffold on the foundation, and the backing board material can be made of wooden scaffold board or channel steel, etc.;
2. A longitudinal and transverse sweeping rod is arranged at 150mm at the lower part of the vertical rod, and the longitudinal sweeping rod is on the ground, and the transverse sweeping rod is below, all of which are connected with the vertical rod;
3. Drainage ditches are set around the scaffolding, and organized drainage is adopted;
4. When the foundation of the scaffold pole is not at the same height, the longitudinal sweeping rod at the height must be extended to the low place by two spans and fixed with the pole, the height difference is not more than 1m, and the distance from the shaft of the pole above the slope to the slope should not be less than 500mm.

Elevation of floor-mounted scaffolding

Sectional view of floor-mounted scaffolding

2. Outside the scaffolding inside protection 1, a special construction plan should be prepared, and approved, steel pipes, fasteners, etc. should be inspected for their certificates when they enter the site, and samples should be re-inspected;
2. The steel pipe of the scaffold should be horizontal and vertical, the large crossbar at the transfer position should not exceed the corner of 200mm, and the exposed part of the small crossbar should be uniform in length;
3. The scaffold pole should be evenly distributed, generally 1500mm, the large crossbar should be kept horizontal, generally 1800mm, and the railing waist bar should be set up for each step of the scaffolding, which is generally 600mm and 1200mm high;
4. The outside of the scaffold is full of dense safety nets, the surface of the scaffold is brushed with yellow paint, and a 200mm skirting board is set up every other group or two groups of scissor supports, which is fixed on the outside of the vertical pole, and the surface of the skirting board is brushed with yellow and black warning paint;
5. The main node must be provided with a transverse horizontal rod, which is buckled with a right-angle fastener and it is strictly forbidden to dismantle;
5. Accept before use, and hang the acceptance plate.

Exterior scaffolding elevation

3. Cantilevered scaffolding 1, a special construction plan should be prepared and approved, and experts should be organized to demonstrate the plan by erecting more than 20m in sections;
2. The cantilever beam of the cantilever scaffold must be made of I-beam above 16#, and the anchor end of the cantilever beam should be greater than 1.25 times of the length of the cantilever end, and the cantilever length is determined according to the design requirements;

4. The specific specifications and models of I-beams, anchor screws and cable-stayed wire ropes are determined according to the calculation of the design plan;
5. The bottom of the scaffold should be set up along the longitudinal and horizontal direction according to the requirements of the specification, and the upper surface of the cantilever beam should be welded with steel bars to fix the vertical rod, and square timber should be laid along the length of the scaffold above the crossbar, and the formwork should be fully paved for protection;
6. A 200mm high skirting board should be set on the inside of the pole at the bottom of the scaffold, and the bottom should be closed with hard materials;

Cantilever scaffolding elevation

Schematic renderings

Schematic diagram 1 of embedded parts

Schematic diagram 1 of embedded parts

Fourth, attached scaffolding 1, attached lifting scaffold user should sign a professional subcontract with a professional qualification unit, the first qualification can undertake all kinds of attached lifting scaffold design, manufacturing, installation and construction, secondary qualification can undertake the design, manufacturing, installation and construction of attached lifting scaffolding below 80m;
2. The special construction plan shall be prepared and approved by the professional contractor, and submitted to the user for review, and the span of the straight line section shall not exceed 7000mm, and the span of the broken line section shall not exceed 5400mm;
3. The product of the height of the frame and the span of the support shall not be greater than 110m2;
4. After the installation of the overall lifting scaffold, the installation unit shall conduct a self-inspection, and the representative of the supervision unit of the project, the technical person in charge of the construction unit and the installation unit shall form an acceptance group to jointly carry out acceptance, sign, and issue acceptance opinions;
6. After each lifting, the construction and installation unit must conduct a comprehensive inspection of the safety device, insurance facilities and lifting system, meet the requirements and repeat the signing procedures before it can be used.

Renderings of the attached climbing frame

5. Horizontal protection of external scaffolding 1. In the main construction stage, the construction layer, the demoulding layer, and the second layer must be fully paved with scaffolding, and the scaffold board must be paved to the building structure, and the probe board is strictly prohibited and fixed firmly;
2. From the second layer, a hard partition protection should be set up every 12mm, and a horizontal safety net should be hung in the middle of it;
3. The outer side of the frame should be closed with a safety mesh net, and the connection between the nets should be tight, and safety warning signs should be hung;

Horizontal protection of external scaffolding

6. Setting of external scaffold connecting wall pieces 1. The connecting wall members of the scaffold should be set close to the main node, and the distance from the main node should not be greater than 300mm;
2. Floor-mounted scaffolding with a height of less than 24m can be made of rigid or flexible walls;
3. Floor-mounted scaffolding with a height of more than 24m is a pick-up scaffold, and only rigid wall pieces can be used;
4. The two ends of the slotted and open frame must be provided with wall pieces.

Schematic diagram 1 of the connecting wall piece

Schematic diagram 2 of the connecting wall piece

7. Elevator shaft operator 1, no matter what method is used, the elevator shaft operator frame and subsequent protection methods shall prepare a special safety construction plan;
2. During the construction of the theme structure, reserve 180 * 180 square holes in the wall, use two 16# I-beams as the support of the operating frame, erect a segmented cantilever, the height of the frame is not more than 20m, and the step distance is not more than 1.6m;
3. Hang a horizontal net in the construction layer, and set up a horizontal protection every two layers and not more than 10m below the construction layer.

Elevator shaft operating frame eight, elevator shaft protection

1. After the elevator shaft steel platform is lifted away, the steel pipe is used to pass through the wall to set up a grid for protection;
2. Wear 2 Φ48.3*3.6mm steel pipes in the reserved hole, and the outer end of the steel pipe is connected and fixed with steel pipe fasteners to prevent slipping;
3. Lay 50*100 wooden fangs on the steel pipe platform, and lay hard materials on top for closed or hung safety horizontal net protection.

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