There are many scaffolding collapse accidents in engineering construction. What is the main reason?

1. Analysis of the main causes of the accident

1. The scaffolding erection did not meet the standard requirements. During the construction of the scaffolding, the construction team did not strictly follow the safety measures such as checking the stress of the scaffolding, adding supports and anchor point reinforcements proposed in the design plan, and adding supports and anchor point reinforcements during the construction and construction. Since the approved scaffolding construction plan was changed, the structure of the scaffolding was arbitrarily changed in order to save trouble, illegal and risky construction, coupled with inadequate supervision, the construction quality was extremely poor, causing the scaffolding to collapse.

2. Product quality and market management issues. The material of the scaffolding does not meet the construction requirements. Among the scaffolds currently in use, inferior and expired substandard steel pipes account for more than 80%, and more than 90% of the fasteners are substandard products. The reason is that in order to participate in competition, small businesses and family-owned workshops have to reduce costs and prices to seize the market. The result of low-price competition will inevitably lead to increasingly poor product quality. Due to the chaos in the construction and leasing market, the lack of an open, fair and fair trading environment and strict quality supervision measures, many construction and leasing companies only seek cheap prices and ignore product quality, leaving some manufacturers with good equipment, strong technology and high quality in the interest of Without protection, companies have stopped production or changed production, and many low-quality and low-priced products from manufacturers with crude equipment and backward technology have flowed into the construction site, posing serious safety hazards to construction. To solve the above problems, the most critical thing is to have a safe on-site construction safety management system and an authoritative quality supervision agency, and implement corresponding functions, such as product quality certification, product standard formulation and implementation, product safety approval, etc.

3. Construction safety management issues. Although the workers in our team who perform scaffolding installation have put forward the qualification requirements for high-altitude operations, because most of our workers are migrant workers, their own quality cannot meet the operational requirements. In addition, our training is just a formality, resulting in This resulted in workers' weak safety awareness, insufficient ability to control operations, and insufficient depth of understanding of the product, which ultimately led to the inability to carry out construction in strict accordance with the requirements during the actual operation. Coupled with the subjective reasons of empiricism, it has laid great hidden dangers for safe production. Secondly, the construction site project department does not have a strong concept of the technical requirements for the implementation of the formwork support system specifications, and the operators are lax. Due to the use of many temporary workers, The work was not carried out according to the construction organization design and construction plan. During the inspection, it was often found that the distance between poles became larger; the operating procedures were simplified, the erection was not carried out according to the procedures prescribed by the company, and strict inspections were not carried out or the inspections were not thorough, resulting in weak links not being discovered in time. , and the inspection responsibilities are not in place. On-site management personnel change frequently, the quality of front-line workers at the construction site is low, and technical explanations and safety training are insufficient. Since construction companies have many projects and scattered locations, it is difficult to conduct comprehensive inspections. Especially for newly recruited migrant workers, migrant worker training and company safety responsibilities cannot be implemented in a timely manner, and safety measures are not in place.

2. Scaffolding safety protection measures

2.1 Scaffolding for structure and decoration should be erected in accordance with relevant regulations, with an outer diameter of 48~51mm and a wall thickness of 3~3.5mm without serious corrosion. Bent, flattened or cracked steel pipe.

2.2 The spacing between structural scaffolding poles shall not be greater than 1.5m, the spacing between longitudinal horizontal poles (large horizontal poles) shall not be greater than 1.2m, and the spacing between transverse horizontal poles (small horizontal poles) shall not be greater than 1m; scaffolding for decoration The spacing between poles shall not be greater than 1.5m, the spacing between longitudinal horizontal poles (large horizontal poles) shall not be greater than 1.8m, and the spacing between horizontal horizontal poles (small horizontal poles) shall not be greater than 1.5m.

2.3 The foundation of the scaffolding must be flat and solid, with drainage measures in place to meet the support requirements of the frame body and ensure that it does not sink or accumulate water. The frame must be supported on the base (support) or full-length scaffolding board.

2.4 The scaffolding construction working surface must be covered with scaffolding boards, and the distance from the wall must not be greater than 20cm. There must be no gaps, probe boards, or flying springboards. A protective railing and an 18cm high toe board should be installed on the outside of the operating surface

2.5 If the clearance distance below the scaffolding construction layer exceeds 3m, a horizontal safety net must be installed below, and the inner entrance of the double-row rack must be connected to the outer wall of the structure When the space cannot be protected, scaffolding boards can be laid.

2.6 The entire frame should be closed with a dense mesh safety net along the inside of the outer frame. The safety nets must be firmly connected, tightly sealed, and fixed to the frame.

2.7 Scaffolding must be connected according to floors and structures. The vertical distance between the connection points shall not exceed 4m, and the horizontal distance shall not exceed 6m. Rigid materials must be used for pull connections. Scaffolding must be equipped with continuous scissor braces to ensure that the overall structure does not deform. The width of the scissor brace shall not exceed 7 vertical poles, and the angle between the inclined pole and the horizontal plane shall be 45 to 60 degrees. Scaffolding taller than 20m should have unloading measures.

2.8 The erection of various types of scaffolding must have special design plans. For scaffolds above 20m tall and special scaffolding, there must be special design plans, and there must be approval and acceptance procedures by the chief engineer.

2.9 For structural internal and external load-bearing scaffolding, the load shall not exceed 270 kg/square meter. The load of interior and exterior scaffolding used for decoration shall not exceed 200 kg/square meter.

2.10 A safe operating distance should be maintained according to specifications between the outer edge of the scaffold and the edge of the external overhead line. Effective and reliable protective measures must be taken under special circumstances. The wire protection frame should be made of non-conductive material, and the foundation pole should be buried in the ground at a depth of 30 to 50cm. The overall wire protection frame should have reliable top-pull connections to ensure the stability of the frame.

2.11 The width of the pedestrian carriageway shall not be less than 1m, the slope of the ramp shall not be greater than 1:3, the width of the carriageway for transporting materials shall not be less than 1.5m, and the slope of the ramp shall not be greater than 1:6. A platform shall be provided at the corners, and Protect according to border protection requirements. The distance between anti-slip strips shall not be greater than 30cm.

2.12 The requirements for scaffolding used for edge, balcony, and foundation pit protection shall be implemented in accordance with the company's scaffolding safety management system.

3. Summary

Scaffolding collapse accidents seriously endanger the lives of construction workers, especially for ultra-high, overweight, long-span projects and special, complex, high-tech large-scale public buildings. *Construction, if an accident occurs, it will cause immeasurable losses. But as long as we first enter the site to check the rods and fastener materials, and effectively implement a series of guarantee measures such as the preparation, approval, inspection and acceptance of the special design and erection plan of the scaffolding, and at the same time strengthen the training of construction personnel, and government departments will increase supervision, And by mobilizing social forces to work together to control the accidents, such accidents will definitely be reduced or avoided.