Features of the space frame structure

Space frame engineering is gradually increasing in people's daily life. As we all know, it is a space frame structure composed of several rods connected according to a certain network space. According to the appearance design of the product, there are flat space frame and inclined spherical space frame, showing the characteristics of the space frame structure of the interior space.

 

The spherical space frame has the characteristics of triple stress, and can bear various stress functions. Generally, the internal structure can be adjusted according to the force standard of the spherical space frame, and has a high safety factor. For the spherical space frame, this is the The rods at the intersection of the upper sky not only bear force but also have the function of pillars, ensuring the comprehensiveness of the space frame project, and the product has good stability, high rigidity and good seismic performance during use.

 

The space frame structure building project can realize the large-span structure of small rods to build large-scale projects. At the same time, the space occupied by the structure is relatively small, and the interior space can be used with greater efficiency.

 

The structure of the spherical space frame has very unique characteristics. It can carry out various stresses by changing the stress state, which greatly stimulates the strength of materials and reduces the consumption of materials. In addition, The raw material of the rods for manufacturing the space frame structure is relatively simple, which is conducive to transportation and storage, and is conducive to improving productivity and ensuring the quality of the project.

What regulations should be complied with when lifting or jacking the space frame structure

 When lifting or jacking the space frame structure, the following requirements should be met:

The construction shall be carried out in accordance with the regulations of the construction organization design.

Steel pipe welders on the construction site shall pass the all-position welding procedure qualification and welder examination of the welded ball joints and steel pipe connections before they can participate in the construction.

The hoisting method should be determined comprehensively according to the stress and structural characteristics of the space frame, under the requirements of quality and schedule, and combined with the local construction technical conditions.

 

The selection of the position and number of lifting points for the hoisting of the grid shall comply with the following requirements:

It should be consistent with the force condition when the space frame structure is in use or the members must meet the force requirements after checking;

The reaction force at the lifting point should be less than the load capacity of the lifting equipment;

The load of each lifting equipment should be close.

After the hoisting method is selected, the reaction force of the hoisting point, the internal force and deflection of the members, the stability of the supporting column and the horizontal thrust of the space frame under wind load should be checked separately during the construction phase of the space frame, and reinforcement measures should be taken if necessary. .

All welds of the welded joint space frame shall be visually inspected and recorded. For the butt welds of the tie rods and balls of the large and medium-span steel pipe space frame, non-destructive inspection shall be conducted, and the number of samples shall not be less than 20% of the total number of welds. The quality standards shall comply with the current national standard "Code for Acceptance of Steel Structure Engineering Construction Quality" 》(GB50205) the requirements for level 2 welds.

Picture taken from: https://www.safsteelstructure.com/

The key factors and solutions that affect the success of the overall installation and construction of the space frame with soil method

The overall installation and construction of the space frame earth method requires relatively high requirements for the construction plan and the operating staff. In terms of safety management, the preparation and approval of the construction plan, safety technical disclosure, staff training and education, and safety inspection and acceptance must be done carefully. In particular, the overall improvement and installation of the grid must be refined and improved in advance from the plan, all possible problems must be considered, and corresponding preventive measures must be taken.

The unified coordinated command and the overall cooperation of all operators are critical, and targeted training and exercises are required before the process is implemented.

The overall improvement plan for space frame processing requires technically perfect measures to address the difficulties and hazards of the construction process. The main points are as follows:

(1) Choose the appropriate number of lifting brackets: According to the space frame weigh, select the appropriate number of lifting brackets to lift the space frame processing project as a whole after calculation.

(2) Fair arrangement of lifting brackets: The arrangement of lifting brackets is very important. If it’s not fair, it will cause uneven forces on the lifting brackets and cause large deformation of the space frame. By checking the overall weight of the space frame and the weight distribution, the position of the lifting bracket is determined, so that the bracket basically divides the space frame weigh. In addition, pay attention to the influence of the position of the hanging points on the force of the space frame members and nodes to avoid deformation or even damage beyond the permitted range.

(3) Correctly erect the hawser cable: the angle of hawser cable erection is controlled between 30 and 45 degrees, and it is tensioned with a 5t hand chain hoist. During the lifting process, the grid members may interfere with the hawser cable. At this time, the spare hawser cable must be erected and fastened first, and then the original cable wind rope should be loosened.

(4) Choose a suitable lifting bracket: Considering the installation height and stability of the bracket, we chose the standard section of the QTZ125 tower crane as the lifting bracket. The lifting bracket composed of the standard section of the tower crane is far more satisfactory in terms of strength and bending performance. The lifting needs of the grid. It is simple and safe to ensure the stability of the lifting bracket.

(5) The ground endurance of the foundation of the lifting bracket should meet the requirements to avoid uneven settlement after the force is applied, and the foundation should be determined by calculation.

2. The chain hoist breaks

The chain hoist is the key facility of the whole process, and it is necessary to ensure that there are no problems in the hoist during the lifting.

To this end, take the following measures:

The position of the gourd is reasonably arranged to ensure that the force of the gourd is even.

Choose an appropriate number of hoists to ensure a certain safety factor when hoisting.

Choose a gourd of fair tonnage to ensure that the gourd is not damaged when it is lifted.

The gourd should be strictly inspected and carefully maintained before use, and it has normal conditions of use.

Always check the quality changes of the gourd during the lifting process to ensure the smooth lifting.

3. Work at high altitude

Space frame installation work should be placed on the ground as much as possible to reduce high-altitude operations and increase the construction safety factor. When the space frame is lifted, the lift area should be set up to prevent unrelated staff from entering the work area.

What kind of construction works is the space frame suitable for?

   Space frame is a space structure made of multiple members connected by nodes in the form of grid, adopt the construction method of factory manufacturing and site installation, which can shorten the period, reduce cost, improve economic performance. A more professional company can supply better Space frame, and choosing better materials can reduce the cost, which will lead a more prominent performance in the durability and aesthetic. 

   Space frame company can be used in the construction of the station roof, the stadium, the stands, the gas station, the theater the exhibition hall and so on. In addition, the dome structure of Space frame company is suitable for large-span roof, because it has the advantages of space force, big stiffness, saving in material, good seismic performance, low building height, attractive appearance. At present, the roof of large stadiums, exhibition halls, cinemas, theaters, industrial factories, warehouses and other construction projects adopts dome structure.

The top chord assembly and welding steps of the space frame

The top chord assembly and electric welding of steel structure space frame work steps:

1.Put in the longitudinal bars of the upper chord plan space frame to check whether the longitudinal parts and specifications of the top chord ball are appropriate.

2.Put in the transverse bars of the top chord plan space frame to check whether the longitudinal parts and specifications of the top chord ball are appropriate.

3. According to the proper adjustment of the diagonal web member of the three-dimensional small assembly module, the longitudinal and transverse bars of the top chord and the electric welding ball are properly in place. The way to adjust the oblique web members to not only laser cut too long bars, but also to open the angle of view of the transverse bars with inverted chains, so that the rods are properly in place. Ensure the proper size of the top chord grid.

4. Adjust the gaps, and weld the upper chord members after the gap foundation reaches the standard.

5. After the upper chord is fixed, weld the lower chord ball and the transverse bar to make the connection strong.

6. Check space frame specifications and push forward gradually.

The installation of web member and upper chord should be carried out in coordination with each other.

7.After the completion of the installation of the space frame pavement, the project acceptance shall be carried out according to the general specifications of the strips or blocks for the installation of the space frame.

8. The space frame to be hoisted must be hoisted (lifted) after the welding process is finished, the welding appearance quality and the welding ultrasonic flaw detector are reported to reach the standard.

The causes of paint loss during the processing of steel space frame structure

The space frame steel structure is sanded and painted according to the requirements of anti-corrosion. The amount of paint is largely related to the thickness of the dry film, as well as the construction method and coating system.

Paint loss caused by the surface roughness of the workpiece.

When painting the spray-treated surface, the film thickness at the peak of the steel plate should be less than the waves film thickness. In order to meet the anti-corrosion thickness requirements at the peak (to avoid pitting corrosion), the paint "hidden" in the pits of the waves is equivalent to being wasted, which is the "steel plate roughness consumption loss". The following table shows the paint loss caused by different spraying methods (expressed in dry film thickness):

Paint loss caused by uneven film thickness distribution

After the film thickness reaches or exceeds the specified film thickness during the acceptance of the paint film after construction, the technical service representative, the supervisor or the owner will sign as normal, but the part that does not meet the specified film thickness will be required to recoat, so it will inevitably cause "excessive thickness" loss. The specific factors leading to uneven distribution of paint film thickness mainly include: worker proficiency, construction environment, simple or complex construction work piece (flat work piece), and construction method (no air spraying, air spraying, brushing, rolling).

Processing and construction waste

Space frame steel structure processing and construction waste refers to the waste of paint that is lost to the surrounding environment or the ground without reaching the surface of the construction workpiece. If there is no air spraying, the loss of paint is about 10-20%, if there is air spraying, the loss of paint is more than 50%, and the loss of rolling is about 5%. When the brush is well controlled, it is relatively less. Bridge spraying in high wind environment can cause more than 100% waste.

Waste of paint remaining in the container. After the paint is applied, the average loss of the paint remaining on the inner wall of the paint bucket and the rubber tube is about 5%.

In summary, the paint loss coefficient during construction is mainly caused by the loss of surface roughness of the workpiece, the loss of uneven paint film thickness, the waste of construction, and the waste of residual paint in the container.

Is the Steel Structure Sound Proof?

 In the case of steel structure, the first elements must be considered, but there are a lot of, especially sound insulation and noise reduction, we should pay great attention to it, then the application of steel structure can really play the actual effect of sound insulation and noise reduction?

(1) After adding the glass fiber cotton, it can reasonably block the circulation of goods in the middle of the gas. Because the sound can be spread, when a sound is blocked by an object as it travels, it can play a relieving effect, so it can reduce the decibel level.

(2) After adding the glass fiber cotton, it can change the actual effect of the audio in the whole sound transmission process. If you change the frequency problem of the audio, you can reduce it. In addition, it can also change the direction of the audio, so it can be solved between each other 

(3) In view of the steel structure, two walls can be applied to the design proposal, and after that have two walls, can give a voice two solutions on top, so a lower than before, and for the steel structure, it can change the malleability, reasonably reduces the solid state fast propagation in the middle of the building, the decrease in speed means that the quality of the sound is just beginning to diminish.

The above content is my detailed introduction of the application of steel structure can really play the actual effect of sound insulation and noise reduction, I hope can help you.