Major casualties caused by the collapse of fastener scaffolding will be repeated and inevitable. The reasons can be summarized as follows:
First, the quality of fastener steel tube scaffolding in my country is seriously out of control. Table 5.1.7 in specification JGJ130-2001 stipulates that the anti-skid bearing capacity of butt fasteners is 3.2KN, and the anti-skid bearing capacity of right-angle and rotary fasteners is 8KN. Some experts found from on-site inspections that it is difficult for products in actual applications to meet this requirement. After a major accident occurred at a construction site, the fasteners were inspected and the pass rate was 0%.
Second, the quality of steel pipes is seriously out of control. A large number of steel pipes without effective anti-rust treatment have flowed into the market. Since they have not been confirmed by an effective quality inspection system, the products cannot provide quality assurance of safe standard loads, which seriously violates the principle of zero quality defects. In addition, in reality, due to unfair Competition has caused construction units and leasing companies to use substandard steel pipes, and some projects even use scrap steel pipes for scaffolding. This has objectively caused the safety of fastener steel pipe scaffolding to be completely out of control. Some experts inspected steel pipes after a major accident in a certain project, and the pass rate was only 50%.
Third, there are issues with on-site erection and construction safety management. The flexible and diverse application characteristics of fastener-type steel pipe scaffolding also bring huge uncertainties in the on-site erection and construction process. The various safety hazards caused by the lack of management, lack of training, lack of unified design command, and lack of responsibility caused by layered subcontracting are simply too numerous to enumerate.
Fourth, wrong application. Based on the experience of developed countries, fastener-type steel pipe scaffolding can only be used for auxiliary connections and scissor braces in other scaffolding and support system applications such as portal frames, bowl-type scaffolding, and disc-type scaffolding. It must not be used to erect any large-scale scaffolding. The scaffolding system cannot be used for support systems with higher load-bearing requirements. As far as the author knows, none of the fastener-type steel pipe scaffolding that accounts for about 10% of our company’s export volume is used to erect large-scale scaffolding or support systems. In the United States, even the construction and maintenance of common two-story villa houses use portal frames. We have never seen the use of fastener-type steel pipe scaffolding to build construction platforms. The reason is simple. If applied in this way, even the quality of American standard fasteners and steel pipe scaffolding fully meets safety requirements. However, because the erection plan is difficult to standardize, the erection process is uncontrollable due to too many manual details and safety cannot be guaranteed. At the same time, compared with portal or bowl-buckle scaffolding, the amount of labor and steel used is doubled. , resulting in a sharp increase in the total cost of the project and a loss of application significance in terms of economic efficiency.
Fifth, wrong standard orientation. The “JGJ130-2001 Safety Technical Specifications for Fastener Steel Pipe Scaffolding in Construction” approved by the Ministry of Construction of the People’s Republic of China on February 9, 2001, and implemented on June 1, 2001, is an earlier industry-standard promulgated by my country. It regulates the erection and dismantling of scaffolding in my country. The design and construction had a profound impact. Technical personnel from many design and construction units carry out system erection and construction design based on the methods and specifications provided by this standard. Many published papers are based on this standard to discuss how to correctly check whether the load of the scaffolding application system is reasonable, whether the erection is correct, and even analyze the causes of scaffolding collapse accidents based on this standard. It is worth noting that after many collapse accidents, the review calculations of load calculations based on these standards are still qualified. In other words, the collapse accident that has occurred should not have happened theoretically. This embarrassing phenomenon itself is caused by the wrong guidance of standards on the application of modified products. “5. Design Calculation” and “6. Construction Requirements” in the standard tell us how to calculate and erect large-scale scaffolding application systems. The “6.8. Formwork Support” section in the standard tells us how to use fastener-type steel pipe scaffolding to erect a support system. These fundamental misdirections stem from the fact that, as mentioned earlier in this article, we still have a lot of vague understanding of common sense that has been confirmed by the application experience of developed countries.
Construction safety authorities across our country have long been aware of these problems and have introduced management measures many times to try to standardize the application and product quality of these products, but these efforts have not been effective. Because fastener-type steel pipe scaffolding has objectively caused many unavoidable threats to construction safety that are difficult to correct in ordinary ways, the practical application of these products must be eliminated, and safety measures such as wheel buckle frames and disc buckle frames should be used instead. and a more efficient system will be an effective means to solve the problem. It is also an inevitable trend in the future construction application of building supports in my country.
Post time: Apr-30-2024