The seismic support "Code for Seismic Design of Building Electrical and Mechanical Engineering" GB50981-2014 has been implemented for several years, but when I chatted with you, I still feel that there are still many clear things. Combined with the factory inspection and the understanding of various brands, today's mechanical and electrical contacts hvac -Mu Zili will talk about his understanding and opinions on the issues that everyone cares about based on his own knowledge.

1. What is a seismic support?

2. Which systems do seismic supports?

3. What are the materials of the seismic support itself? What are the advantages and disadvantages?

4. How to install the seismic support?

5. Will the seismic support affect how to deepen cooperation and optimize the net height project at the same site?

6. How to check the correctness of the design calculation? How to investigate and deal with the tricky calculations?

7. How deep is the manufacturer's deepening? Is there a fee for cooperation?

8. How to distinguish the mixed products on the market?

9. Which department is the local area for the acceptance of seismic supports? What is the acceptance method? Which systems do you need?

1. What is a seismic support?

Definition: It is firmly connected with the building structure, and the seismic force is the main load. It is composed of anchor solids, reinforced booms, seismic components and seismic braces.

2. Which systems do seismic supports?

According to the relevant standards of GB 50981-2014 Code for Seismic Design of Building Mechanical and Electrical Engineering:

1. Domestic water supply system, fire piping system, air conditioning and heating system:

Metal pipes with a pipe diameter ≥ DN65 shall be designed for seismic support and hanger.

2. Air duct system:

Anti-fume exhaust ducts, accidental ventilation ducts and related equipment should adopt earthquake-resistant supports and hangers, and all anti-smoke and accident ventilation ducts should be designed with anti-seismic supports regardless of their size. (Strong bar)

Air-conditioning ventilation duct: Rectangular duct cross-sectional area ≥0.38 square meters or circular duct diameter ≥700 should be designed for seismic support and hanger.

3. Electrical system:

Electrical piping with an inner diameter of not less than 60mm should be designed for seismic support

The bridge frame and bus duct with gravity not less than 150n/m (15KG/M) should be designed with seismic support.

4. Gas system:

Gas pipelines with an inner diameter greater than or equal to 25MM should be designed for seismic resistance.

(For example, there is a conflict with the specification, and the specification is limited)

3. What are the materials of the seismic support itself? What are the advantages and disadvantages?

Q235B is usually used in the market. There are cold galvanizing (electroplating) and hot-dip galvanizing. The thickness of the cold galvanized galvanized layer is thicker, and the thickness of the hot-dip galvanized galvanized layer is thicker. Hot-dip galvanizing (the thickness of the galvanized layer is usually 70~80μm), and the accessories are electroplated (the zinc layer is usually a few μm). Some manufacturers also use other materials for the brackets. For example, we investigated a manufacturer recommends using zinc-aluminum-magnesium profiles. It is said that this material has better anti-corrosion performance, but the price is also cheaper.

4. How to install the seismic support?

The seismic support and hanger system is modified to consist of C-shaped finished channel steel, special seismic connectors, pipe clamps, and expanded bottom anchor bolts for cracked concrete. The seismic connectors and channel steel can be mechanically connected to adjust the size of the seismic support and hanger. ,height. The seismic support and hanger should never be welded on site, and the anchor bolt and the original concrete structure should be reliably connected. The steel structure adopts prefabricated bolts or beam clamps.

Note: Later, the expanded bottom anchor bolt is used to grip, which is said to be more and more credible.

The following provides a few typical installation instructions for seismic support:

1. Double-line support for air duct

2. Bridge one-way support

5. Will the seismic support affect all living beings? How to deepen cooperation and optimize the project on the same site?

Looking at the installation diagram below, everyone first feels that the appreciation at the integrated pipeline will affect the height of the pipeline arrangement. If the site construction unit does its own work, the final span cannot be controlled, so later seismic support must be deepened and optimized. Especially for integrated pipelines, integrated seismic supports should be used.

How to cooperate on site and when will the seismic support deepening enter the site? At present, many tender sections are placed in the electromechanical general contractor, or in the professional subcontracting tender section. The electromechanical general contractor needs to arrange the integrated pipelines uniformly and consider the deepening of the seismic support. The following is the cooperation provided by a manufacturer Process.

Note: The current design institute of anti-seismic brackets does not actually do any design. The design description is missing a word and the manufacturer will deepen it instead.

Since everyone does not understand the design ideas of seismic support, especially without strict review standards, Party A, consultants, and design institutes can never professionally judge whether the deepening design is appropriate based on calculations. For example, winning the bid will reduce the number of earthquake-resistant supports; therefore, after winning the bid, the deepening needs to increase the support for various reasons. How to control it? I personally think that we can discuss a mode of referring to intelligent design. The seismic support is divided into design bids and supply bids. In the construction drawing design stage, the seismic support design is involved, and the pipeline is optimized with the construction drawings. It can also get better and better in the later period. Control the span immediately.

6. How to check the correctness of the design calculation? How to investigate and deal with the tricky calculations?

It is mentioned below that the current seismic support is usually deepened by the manufacturer. There may be a trap in the deepening. It is disadvantageous, or it may be over-designed or difficult to design. For you who are not very professional, how to judge the basic rationality? ?

Generally, when bidding, we need the professional seismic support calculation software with the copyright of the seismic support manufacturer. The software needs to be certified by a third-party authority to ensure the reasonableness and correctness of the calculation. The load value of the seismic support accessories requires a third party. Test report, etc.

7. How deep is the manufacturer's deepening? Is there a fee for cooperation?

Usually, after bidding, provide project quotation and preliminary design plan; after winning the bid, provide detailed construction drawing plan; including seismic support location map, seismic support node detailed map, seismic support material list, seismic support calculation book, on-site installation guidance.

Under stable conditions, the winning bidder will never charge a fee, but the wool is on the sheep and the quotation should be considered comprehensively.

8. How to distinguish the mixed products on the market?

Because the seismic support requires a relatively long implementation time, the current developers and consulting companies do not have a very clear brand library. In the later stage, it is important to use some brands of standard compilation units, which also led to the extremely low prices of these domestic brands in the past.

Many manufacturers in the market see business opportunities and are rushing to join the production and supply of seismic supports. How to identify the mixed products on the market?

You can refer to the basic idea of consultant brand storage.

The first step: product exchange. Provide exclusive calculation software, test 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 the production process, factory management and annual output to ensure product quality and supply capabilities.

The third step: project inspection. Conduct on-site inspections of projects that have been implemented, inspect on-site installation quality and on-site feedback.

Note: For a horizontal comparison of a number of different brands, a recognized brand can also be used as a measurement standard for confirmation.

9. Which department is the local area for the acceptance of seismic supports? What is the acceptance method? Which systems do you need?

At present, the acceptance department serves as a quality inspection station!

Acceptance method: It is based on the design drawing and the specific installation situation on site. Certain projects will require destructive testing. At present, most of the specific systems for the project are: ventilation, water supply, fire hydrant, sprinkler, electrical system to prevent smoke and exhaust accidents. (The gas is usually changed to the gas company).

The ventilation to prevent smoke and exhaust accidents is in boldface. Some projects only did this part in the past, but there were feedbacks that other systems were also added at the final acceptance site, which must be limited by local requirements.

Thanks to many professional manufacturers for providing relevant information and support, personal views, such as the wrong place or not mentioned in the article, welcome everyone to leave a message, and I will have the opportunity to discuss it again!