The specific reasons are as follows: steel scaffold The foundation of pipe scaffold was not hardened or tamped with concrete; when pouring on site, it violated the requirements of symmetrical pouring in the special construction scheme, adopted asymmetrical pouring on the sloping roof of the portal building, and the support system collapsed due to uneven stress; after pouring the vertical structure on site, it failed to pour the horizontal component after the vertical structure strength reached 50% in the scheme According to the requirements of the project, the beam and slab pouring was started immediately; some materials were unqualified, resulting in the bearing capacity and stability of the scaffold lower than the design expectation of the special scheme; some steel pipes fell during the erection or dismantling of the scaffold; the scaffold step distance was inconsistent with the scheme, and no special design calculation and expert argumentation was carried out when it was more than 50m; butt fastener was not used for the lengthening of the scaffold pole; the shear strength of the scaffold The knife bracing should not be set continuously from bottom to top, the width of cross bracing should be less than 4 spans and less than 6m, and the inclined angle between the diagonal bar and the ground should not be between 45 and 60 degrees as required; in the construction of steel structure of the plant, the inter column support and roof horizontal support were not installed, the manufacturing and installation position of roof horizontal tie bar did not meet the design requirements, and the steel beam with span greater than 6m was not provided with temporary support, which led to the failure of steel support in the plant The out of plane stiffness of structural system is insufficient
. 
1
.
5
.
Before the construction of the project, the scaffold design should be carried out and the construction technical scheme should be prepared
.
The common problems of scaffold materials in construction site include: insufficient diameter or wall thickness of steel pipe, poor fastener material, insufficient strength of connecting bolt, uneven base deformation, insufficient thickness of steel (wood) scaffold board, etc
.
There are some potential safety hazards in the process of installation and dismantling of this kind of scaffold, which may cause different degrees of safety accidents
.
As one of the major hazard sources of construction engineering, scaffolding engineering needs the relevant units to strengthen supervision
.
Therefore, it is very important to strengthen the protection of safety net and scaffold board to reduce the accident damage
.
The statistical analysis of the data in 2020 is as follows: as can be seen from the above figure, relatively few scaffold collapse accidents are major accidents, accounting for 30.43%
.
Each special construction scheme shall be strictly reviewed to ensure feasibility and safety before implementation
.
Prevention and control measures Ruijie classified and analyzed the causes of scaffolding collapse accidents in 2020, which can be roughly divided into five categories: safety protection, safety awareness, scheme, design, material problems and site management
.
3
.
4
.
Strictly implement the erection and dismantling work according to the design and scheme, strengthen the training of construction personnel, strengthen the supervision of government departments and mobilize social forces to jointly manage, which will effectively reduce or even avoid the occurrence of such accidents! Data source: Ruijie knowledge base and Ruijie database review in the past! How can Ruijie leverage the development of enterprises with talent “fulcrum”? Let the building “pass” the temperature, the good house of 100 billion real estate enterprises was built like this! Choose the right building waterproof method and say goodbye to leakage!.
.
At the same time, combined with Ruijie database, in the 5944 times of safety assessment conducted by Ruijie in 2020, the scores of the national average safety score of the whole project and the average safety score of the scaffold are as follows: from the above figure, it can be seen that the safety assessment score of the scaffold project (0.75) is 0.1 points lower than the overall safety assessment score of the bid section (0.85)
.
It can be seen that more attention should be paid to the construction according to the design scheme and the supervision of the erection and demolition process strictly according to the scheme
.
Standardize the scaffold scheme design and the audit mechanism of special construction schemes such as erection and demolition
.
Strengthen the safety net, scaffold board protection, scaffold board, safety flat net, cross bar, anchorage and other key nodes in the erection process are loose and not tightly connected, which is easy to cause personnel falling accidents
.
However, according to the analysis of the number of deaths in each accident, it can be seen that the probability of death in the accident is relatively high, up to 69.57%
.
In recent years, the domestic construction engineering accidents caused by the collapse of scaffolding occur frequently
.
Statistics of casualties and missing persons in the 23 collapse accidents in the whole year, a total of 108 people were killed or missing, especially in the scaffolding collapse accident in Longchuan, Heyuan on May 23, which resulted in 8 deaths and 1 injury, with heavy casualties
.
Through the application of public opinion monitoring in knowledge base, Ruijie combed the relevant information reports of scaffolding collapse in 2020, and reviewed them one by one
.
Strengthen the construction site management, scaffold and support frame erection and demolition scheme must be approved, and safety technical disclosure shall be conducted to the operators before implementation
.
2
.
The scheme design includes the strength calculation, structural measures, material category and specification selection of the supporting system itself and the floor and ground supporting the formwork
.
Conclusion according to the above accident statistical analysis, scaffolding collapse accident seriously endangers the lives of construction personnel, especially for super high-rise, large-span, high-tech construction projects, the occurrence of scaffolding collapse accident will bring immeasurable losses to relevant enterprises, units and society
.
Accident cause analysis at present, most of the construction sites in our country adopt fastener type steel pipe scaffold
.
Strengthen the management of scaffold materials, and strengthen the quality control of scaffold components and accessories by all parties involved in the construction of the project
.
In 2020, a total of 23 scaffold collapse accidents occurred in China, resulting in 48 deaths, 57 injuries and 3 missing persons, 69.57% of which were fatal
.
The operator shall carry out the construction in strict accordance with the design and construction technical scheme of the formwork, and shall not change the requirements of the formwork design at will
.
Improve the safety awareness of employees, improve the safety awareness of management personnel, carry out detailed safety technical disclosure or safety education for construction personnel, and scaffolders can work only after professional training
.
Five prevention and control measures combined with the five accident cause types analyzed above, the specific prevention and control measures can be improved from the following directions
.
Ruijie found that the scaffold occurred in 2020 basically belongs to this category after analyzing the collapse accident cases
.
In this paper, through the analysis of the relevant data of scaffolding collapse accidents in 2020, we can understand the situation of this kind of accidents in China, and put forward the corresponding preventive measures for the causes of the accidents
.
The scaffold erection calculation sheet and design drawings shall be attached to the scheme
.
The results are as follows: among the problems, the score of safety awareness is relatively high (0.86), while the score of scheme and design is the lowest (0.69), followed by site management (0.76)
.
According to the statistics of monthly accidents in 2020, except February and July, such accidents occur in other months, which is a major “stubborn disease” in the field of construction engineering
.
Accident area distribution from the perspective of accident cases, it is mainly distributed in East China, South China and central China, especially the economically developed, large-scale construction and intensive engineering areas in East China and South China, accounting for 64% of the total, as shown in the figure below: accident type distribution the judgment of Engineering accidents in China follows the following principles (extract part): major accident: causing more than 3 people and 10 people The following accidents are caused by death, or serious injury of more than 10 people and less than 50 people (including acute industrial poisoning, the same below), or direct economic loss of more than 10 million yuan and less than 50 million yuan; general accidents are caused by death of less than 3 people, or serious injury of less than 10 people (including acute industrial poisoning, the same below), or direct economic loss of less than 10 million yuan
.
The formwork can only be put into use after passing the acceptance
.
