The seismic support code, "Seismic Design Code for Construction Mechanical and Electrical Engineering" GB50981-2014, has been around for several years now. Then, on December 28, 2018, the National Standardization Committee officially released the second industry national standard, GB/T 37267-2018 "General Technical Conditions for Building Seismic Support Hanging". However, even after discussing it with you, I still feel like there are quite a few unclear aspects. Today, the editor has summarized the concerns everyone has:
1. What exactly is a seismic bracket?
A seismic bracket is a facility firmly connected to the building structure, primarily loaded by seismic forces. It includes an anchor, reinforced boom, seismic connection member, and seismic diagonal brace.
2. Which systems require seismic supports?
According to the relevant standards and regulations of the seismic design specifications for construction mechanical and electrical engineering:
Article 1.0.4 (Strength Strategy) states that construction mechanical and electrical engineering projects in areas with seismic design intensity of 6 degrees or above must undergo seismic design.
Article 3.1.6 specifies the contents that need to be seismically reinforced: â‘ Equipment with gravity greater than 1.8kN in suspended pipelines; â‘¡ Domestic water supply and fire protection pipeline systems with DN65 or above; â‘¢ Air duct systems with rectangular cross-sectional area greater than or equal to 0.38 square meters and circular air duct systems with circular diameter greater than or equal to 0.7m; â‘£ Electrical conduits with inner diameter greater than or equal to 60mm and cable ladder frames, cable duct boxes, and busbar ducts with gravity greater than or equal to 150N/m.
Article 3.1.8 stipulates that building electromechanical engineering pipelines passing through the seismic insulation layer should adopt flexible connections or other methods, and seismic supports should be installed on both sides of the seismic insulation layer.
Article 4.1.2.1 states that when the straight length of water supply and drainage pipes in high-rise buildings in 8 degrees and 9 degrees is greater than 50m, anti-vibration measures should be taken; when the straight length is greater than 100m, anti-vibration measures should be taken.
Article 4.1.2.3 states that when indoor water supply, hot water, and horizontal pipes with diameters greater than or equal to DN65 that need to be forged are fixed with hangers, brackets, or brackets, earthquake-resistant support should be set up as required.
Article 5.1.2.4 states that the pipelines in boiler rooms, refrigeration machine rooms, and heat exchange stations should have reliable lateral and longitudinal seismic supports. For multiple pipes, a door-type seismic support bracket or a single pipe support bracket with a pipe diameter of more than or equal to 300mm should be used.
Article 5.1.3.3 states that air ducts with a rectangular cross-sectional area greater than or equal to 0.38 square meters and a circular diameter greater than or equal to 0.70m can use a seismic support hanger.
Article 5.1.4 (Strong Article) states that smoke-proof air ducts, accident ventilation ducts, and related equipment should use earthquake-resistant support and hanging frames.
Article 5.1.5.4 states that air conditioning units, fans, and other equipment with gravity greater than 1.8kN should not be lifted and installed. When lifting is necessary, it should be avoided above the positions of personnel activities and evacuation passages, but earthquake-resistant support hangers should be installed.
Article 6.1.1 states that gas pipelines with an inner diameter greater than or equal to 25mm should be designed for earthquake resistance, and the installation of pipeline earthquake resistance support and hanging frames should comply with regulations.
Article 6.2.8 states that in buildings with a building height greater than 50m, gas pipelines should be equipped with seismic support at appropriate intervals according to the building's seismic requirements.
Article 7.1.2 states that electrical conduits with an inner diameter of not less than 60mm and cable ladder frames, cable duct boxes, and busbar ducts with a gravity of not less than 150N/m should be seismically protected.
3. What are the materials of the earthquake-resistant brackets themselves? What are the advantages and disadvantages?
Q235B is generally used on the market, including cold galvanizing (electroplating), hot-dip galvanizing, and dacro. The thickness of the cold galvanized galvanized layer is relatively thin, while the thickness of the hot-dip galvanized galvanized layer is relatively thick. Currently, the brackets are mostly hot-dip galvanized (the thickness of the galvanized layer is generally 70~80μm). The age of hot-dip galvanized in general environments can reach more than 30 years. The neutral salt spray test is between 300-500h, and its price is much higher than cold galvanized, which also has certain pollution to the environment. Dacro is a zinc-chromium coating process with a film thickness of only 4-8μm, but its rustproof effect is 5-10 times that of traditional electro-galvanized galvanized, hot zinc, or paint. The neutral salt spray test is more than 1,200 hours, and it has no pollution to the environment. Fanzu's VZ-MASK super anti-corrosion coating has super anti-corrosion properties, and its rustproof effect is more than 10-20 times that of traditional electro-galvanizing or coating methods. The support hanger treated with the Musk coating process can withstand neutral salt spray tests for more than 3000 hours without red embroidery, and its service life can reach more than 100 years, and it is pollution-free to the environment.
4. How to install earthquake-resistant brackets?
The seismic support and hanger system consists of C-type finished channel steel, special seismic connections, pipe clamps, and rear-end expansion anchor bolts for cracked concrete. The seismic connections and channel steel can be mechanically connected to the size and height of the seismic support and hanger. The seismic support and hanger should not be welded on site, and the anchor bolts should be reliably connected to the original concrete structure. The steel structure is fixed by prefabricated bolts or beam clamping clamping.
The lateral seismic support hanger is used to resist the action of lateral horizontal seismic forces.
Longitudinal seismic support hangers are used to resist longitudinal horizontal seismic forces.
The single-tube (rod) seismic support hanger is a seismic support hanger composed of a load-bearing hanger and a seismic oblique brace.
5. Will seismic stents affect net height? How to deepen cooperation and optimization of projects with the site?
Look at the installation diagram above, everyone feels that the height of the pipeline layout will definitely affect the comprehensive pipeline. If the on-site construction units do their own things, the net height in the later stage will not be controlled, so the early seismic support must be deepened and optimized, especially for the comprehensive pipeline, comprehensive seismic support should be used.
How to cooperate on the site and when will the seismic support deepening be launched? At present, many sections are placed in the general contractor of electromechanical and electrical conscription, or in the sections of professional subcontracting. The general contractor of electromechanical and electrical conscription requires the unified arrangement of comprehensive pipelines and considering the deepening of seismic support.
Given that everyone does not understand the design ideas of earthquake-resistant brackets and especially does not have strict review standards, it is impossible for Party A, consultants, and design institutes to professionally judge whether the deepening design is reasonable based on the calculation book alone. If you want to win the bid, the number of seismic stents will be reduced; and if you deepen the bid after winning the bid, you need to add the stent, etc. How to control it? I personally think that a model of reference intelligent design can be discussed. Seismic support is divided into design standards and supply sections. During the construction drawing design stage, seismic support design will intervene and cooperate with the construction drawings to optimize the pipeline, so that the net height can be actively controlled in the early stage.
6. How to check the correctness of design calculations? How to investigate and deal with the tricks in calculations?
As mentioned above, the current earthquake-resistant brackets are generally deepened by the manufacturer. There may be tricks in deepening, which are beneficial to it, or more or less designed. For you who are not very professional, how can you judge its basic rationality?
Generally, during bidding, the manufacturer of earthquake-resistant brackets needs to have their own copyrighted professional earthquake-resistant bracket calculation software. The software needs to be certified by a third-party authoritative organization to ensure the rationality and correctness of the calculation. The load value of earthquake-resistant bracket accessories requires a third-party inspection report, etc.
7. How deep has the manufacturer achieved? Is it charged for cooperation?
Before the general bid, the project quotation and preliminary design plan are provided; after winning the bid, detailed construction drawings are provided; including seismic support position diagram, seismic support node details, seismic support material list, seismic support calculation book, and on-site installation guidance.
Under normal circumstances, the winning bidder does not charge a fee, but the wool comes from the sheep, so the quotation should be comprehensively considered.
8. How to distinguish between products that are mixed in the market?
Due to the short execution time required by seismic brackets, developers and consulting companies do not have a clear brand library. In the early stage, some brands from standardized compilation units were mainly used, which also led to the extremely high prices of these domestic brands. Many manufacturers in the market have seen business opportunities and have joined the production and supply of earthquake-resistant brackets. How to identify products that are mixed in the market?
You can refer to the basic ideas of consultant brand inventory.
*Step: Product communication. Provide exclusive computing software, testing reports, third-party certification materials, and appropriate project cases, etc., to understand and verify the basic situation of the brand.
Step 2: Factory inspection. Understand production processes, factory management, and annual output to ensure product quality and supply capacity.
Step 3: Project inspection. Conduct on-site inspections of implemented projects to inspect on-site installation quality and on-site feedback.
Fanzu not only participated in the drafting and editing of the National Building Standard Design Drawing Collection 16D707-1 and the seismic installation industry standards of building electrical facilities but also specially set up a new product model research and development center, a new material mechanics development center, and introduced special earthquake testing instruments and mechanical performance experimental instruments to continuously make breakthroughs and innovate, and provide you with the best support and hanger system products.
9. Which department is the acceptance of earthquake-resistant brackets in various places? What is the acceptance method? Which systems should be done?
Currently, the acceptance department is a quality inspection station!
Acceptance method: Comparing the design drawings with the actual installation situation on site. Individual projects will require disruptive testing. Currently, most of the projects actually do systems: ventilation, water supply, fire hydrant, spraying, and electrical systems for anti-smoking accidents. (Gas is generally made by gas companies).
Among them, the ventilation of smoke and exhaust accidents is bold. Previously, there were projects that only did this part, but there were also feedbacks that other systems were added to the later acceptance site. The specific requirements shall be subject to local requirements.
Architecture is a business card of the city. "Safety, wisdom, and energy saving" are the direction and future of architectural design. Guangzhou Fanzu Construction Technology Co., Ltd., as a high-tech enterprise integrating the design, production, research and development and sales of installed seismic support and hangers, will rely on its industry's best production and R&D technology to ensure the safety of people's lives and property with its excellent product quality.
Chinese Red Shingle Tile,Blue Black Shingle Tile,Coffee Black Shingle Tile
Shandong Yahong New Materials Technology Co., Ltd , https://www.okrooftile.com