Scaffolding safety

Just coming to the construction site, looking at the works has seen the slogan: Safety first; Safety is you, accidents are enemies or like: production must be safe, safe for production; there are places that say “Safety first” in English. Everyone is assured that the occupational safety issue at the construction site is very focused.

Scaffolding is one of the key occupational safety issues in construction. Scaffolding is a temporary structure serving in construction to withstand the temporary impact of the above load while the structure itself is not able to bear the load enough or has no other bearing structures to replace. Scaffolding system supporting the load above and transmitting down should be carefully calculated, fabricated and installed in accordance with the new design to ensure safe use.

Scaffolding requirements: Scaffolding should be designed for each use case: According to Circular No. 22/2010 / TT-BXD on occupational safety in construction: “Before starting construction The construction method must have the approved construction method design, the construction method must show solutions to ensure occupational safety for workers and construction machinery and equipment for each job “. Construction contractors, including the general contractor, main contractor and subcontractor on the site, are responsible for: preparing and approving the design of construction measures, clearly specifying the safety measures. for people, machines, equipment and projects. Periodically or irregularly inspect the site developments to adjust construction measures and labor safety measures accordingly. To recruit and arrange technical workers on the construction site with the right expertise, qualified practice, and healthy as prescribed by law. At the same time providing a full range of personal protective equipment for employees.

This provision in Circular 22/2010 / TT-BXD can be understood that before using the scaffolding as a formwork support system or using the scaffolding as a means of accessing the construction site, the Contractor should make an argument. construction method and organization of approval for this construction method. The construction method approved by the contractor must be approved in writing by the investor and allowed to be used for the construction of the work.

Requirements when designing scaffolding construction measures:

There are two important criteria used when designing and constructing scaffolding:

• Enough bearing (guaranteed in intensity)
• Ensuring the stability of the scaffolding structure

To ensure that the criteria meets the strength requirements, it is necessary to:

• Calculate enough loads related to scaffolding

The loads for calculation of formwork scaffolding refer to Appendix 1 of TCVN 4453: 1995 full-block reinforced concrete and concrete structures – construction and acceptance codes.

• In addition, for structures with very heavy loads, such as scaffolding supporting formwork systems for chain beam structures in the construction of high-rise buildings, all impact loads related to scaffolding must be included. will lead to the malfunction of the scaffolding system that is not able to carry enough load, so the bar material is damaged and damaged.
• When calculating the intensity of scaffolding, to check the bearing capacity of each bar in the scaffolding system and the bearing capacity of bars when joining the bars into the scaffolding system.
• Care should be taken when connecting short to long bars, it is necessary to check the strength at the joint between bars.
• Scaffolding materials are good enough to be used. It is necessary to strictly check the quality of materials used as scaffolding. Bamboo, wood, rotted, termite or defective due to human mechanical impact, cannot continue to be used. Metal bars and pipes in steel scaffolding, if corroded, rusted or deformed due to impact, dented or crushed, shall not be used.

To ensure the stability of the scaffolding system must check:

• Check the stability of each bar according to the criteria of the slenderness of the bar.
• Check the system’s stability when joining bars into flat or space truss.
• Measures to ensure the friction (face pressure) of the head on the truss bars with the above load impacting on the scaffolding.
• Need to ensure absolute safety for supporting structures under scaffolding. This supporting structure must have sufficient load capacity, not be displaced by slippery or other forced displacement.
• The scaffolding system must be anchored, attached to the project to prevent displacement of the whole system due to horizontal loads such as wind, whirlwind or earth vibrations for different reasons (near blasting, near large trucks. , other reasons for vibrations…).
• Pay special attention to the links between the scaffolding bars: must ensure the correct alignment of design conditions for export. The bonding materials must be new, ensuring design criteria and the bonding positions must be constructed well, tight and durable.

Scaffolding material to expose the sun and rain should be checked periodically and regularly. Examinations should be 10 days in the dry season and 7 days in the wet season.

• It should be very careful when designing, testing and erecting the scaffolding system which are bracing bars, bracing structure. Bracing bar and bracing structure create stability for the scaffolding system, prevent deformation and instability.

Risk of unsafety: falling high while working on scaffolding (construction, repair, cleaning …) due to collapsing, collapsing, slippery … Falls high when moving, climbing on scaffolding roads, walking on scaffolding. High falls due to violations of safety procedures without using safety belts, high falls due to working on scaffolding that are not properly installed, scaffolding has no working floor or not ensuring safety, due to fracture or collapse working platform. Russia moved, climbed up, down the scaffolding. Falling high due to the effect of welding, causing dazzling, due to insufficient night light, startling during work.

Therefore, to ensure safety, people working at high altitude must meet the following requirements: from 18 years of age and older, with a certificate of health assurance by the medical authority. Every 6 months, you must have a health check-up. Pregnant women, people with heart disease, blood pressure, deaf ears, and poor eyes are not allowed to work on high. Having a certificate of learning and testing to meet occupational safety requirements confirmed by the Director of the unit. Equipped and instructed to use protective equipment when working at high altitude: safety belts, clothing, labor helmets. Workers must absolutely obey the discipline and labor safety regulations working on high. Well implementing the rules of discipline and occupational safety when working at high altitude: it is necessary to wear seat belts in the prescribed places. The travel and relocation of the workplace must comply with the right place, right route, prohibit climbing to get up and down an elevated position, prohibiting walking on the top of walls, girder tops, beams, roof trusses and other constructing another structure. At night, heavy rain, high winds, thunderstorms or strong winds of grade 5 or higher are not allowed to work on high scaffolding, chimneys, water towers, towers, pillars or girders, 2-storey roofs or more.

Scaffolding for workers working at high altitude, as well as scaffolding and improving scaffolding must be done by technicians in charge.

Scaffolding must be sure. Handrails must have a height of 0.9-1.15m above the floor surface. The distance between the rig and the ship is not more than 200mm.

• Scaffolding must be fixed to avoid swaying (if it is a hanging truss).
• Husband scaffolding must ensure firmness and certainty.

Gantry cable cars must meet technical requirements, must be checked once a month if replacement is not guaranteed. The overlapping scaffolding heads must be firmly fixed with steel wire and cable. Ensure no break, slip between 2 rigs together. All materials used as scaffolding, pedestals must be periodically checked with a period not exceeding 6 months to determine the quality, including the quality of welds. Everyone must wear seat belts when working at a height of over 2 m. In addition, depending on each specific case, if there are many obstacles below: sharp objects, electricity, moving objects that can endanger workers’ lives, seat belts must be worn when working. at an altitude of 0.5m or more.

Comply with the regulations on occupational safety while working at high altitude. There is a lightning protection system for high scaffolding. High scaffolding made of metal necessarily has its own lightning protection system. When checking and checking scaffolding must consider the following issues: is the scaffolding diagram correct in design, is the column vertical and the foot of the column placed on the wooden plate to prevent settlement? Are there enough bracing systems and scaffolding anchor points to the structure to ensure firm and stable rigidity? Are the linkages strong? Are the working floor edges, openings and staircases fitted with sufficient safety guardrails. For mobile scaffolding (chair scaffolding), when standing in place, the wheels must be firmly fixed. The way to move scaffolding must be flat. Moving the mobile scaffolding must be done slowly. It is forbidden to move mobile scaffolding if there are people, materials, trash cans … Working floor must be sturdy, ensure to withstand calculated load, not slip, the gap between floor boards must not exceed. 10mm. The material selected for the floor must be of sufficient strength, meet practical requirements, be free from chemical corrosion and resist atmospheric erosion.