Techniques and details of high-altitude bulk loading of space frame roof structures

The space frame roof structure installation adopts high-altitude bulk, so it is necessary to set up an installation platform. In order to improve the construction progress, a scaffolding platform is adopted. The platform surface should be between 0.3 and 0.8m from the bottom chord of the space frame, and the space frame steel bar should be placed on the ground according to the construction sequence, and hoisted to the installation platform in sequence. Each lifting should not exceed 0.5 tons, and the lifting equipment should be hydraulic crane on site. After the components are lifted to the platform, they should be placed according to the installation position immediately to prevent the components from being stacked together. Before the installation of the grid, Before installation of each space frame,in addition to the careful inspection of the steel bar and bolt balls during production, the number check of the steel bar and the bolt balls and the inspection of the external dimensions should be carried out to match the positive and negative deviations of the steel bar and bolt balls.

Generally speaking, there are two main ways to install the space frame roof structure, one is the direct splicing of steel bar, and the other is a small unit installation. During the installation process, the above two methods can be combined and constructed at the same time, and the high-strength bolts must be in place when tightening. The multi-pass tightening method is adopted. After the bolts are tightened, the set screws are tightened. Finally, all the joints and the redundant bolt holes on the node ball are filled tightly with an oil brush, and two coats of anti-rust paint are applied.

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How to Control the Installation Deviation of the Bolt Ball Space frame

        There are generally deviations in the installation of the bolt ball space frame. How to reasonably control deviations during installation and avoid deviation accumulation? SAFS steel structure Engineering Company has organized three ways for your reference:

1. The embedded parts should be leveled and the axis of the spring should be leveled to ensure that the rubber bearings meet the installation requirements under the design standards. Properly dispose of embedded parts that do not meet the conditions.

2.  Prevent the overall space frame from settling before forming. Give enough grid support points on the actual operating platform.

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3. After each unit or multiple units are installed, the grid must be checked and recorded step by step to prevent deviations in the processing and production process from accumulating during installation. If it is found that the deviation accumulation is too large in the whole process of the installation, which affects the subsequent installation, it is necessary to stop the installation, analyze the reasons, and make rectifications in time.

For large-span space frames, when installing a single-span, the bolts cannot be tightened at one time, so as to adjust the deviation of the rubber bearing caused by the accumulation of deviations or the insufficient support of the scaffolding platform in the later stage. Adjusting the height of the platform support can be adjusted with a jack, but the strength and stability of the scaffolding must be ensured.

The design and material of the steel structure carport must have corresponding requirements

 If we want the large steel structure carport we build ourselves to be of good quality, then we must have corresponding specifications in the design and selection of materials. How to do it? Here are five points to share with you.

First of all, when we design, we must consider the toughness of the SAFS steel structure carport. When designing, we cannot because the plasticity of the steel is better and ignore the effect of force, so that after the construction is completed, there is only aesthetics.

Second, after the construction is completed, we must also regularly repair it, especially with the increase of use time, there will be some problems on the surface of the steel structure carport, we must repair it as soon as possible.

Third, when we choose steel, we must choose good toughness, so that when we use it, we can reduce the cracking situation.

Fourth, when we are processing, we must choose the appropriate processing technology according to the state of the steel, otherwise it will have a great impact on the strength and toughness of the steel structure carport.

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Fifth, the material used in the steel structure carport must have good durability, so that it can have a good life when it is used. Otherwise, we need to replace or repair it regularly when we use it.

Precautions of space frame construction in rainy period

In the rainy period, the construction of the space frame structure project must be considered carefully, pay attention to the influence of various factors, and make the correct treatment method according to the actual situation.

1. For the earthwork piled up on the construction site, measures should be taken to prevent rain erosion around the site. For example, put strip stones around to prevent the earthwork from being washed into the excavated foundation groove or pipe trench by rainwater. Or bury some infrastructure that has already been completed. After the foundation construction is completed, the backfilling work around the foundation pit should be carried out as soon as possible. When artificial precipitation is stopped, the anti-floating stability of the box-shaped foundation and the buoyancy of groundwater on the foundation should be checked, and the anti-floating stability coefficient should not be less than 1.2. Stop construction when the impact of rain is great. What is being excavated is mainly supported by slowing down edge breaking.

2. The working surface of the space frame during the rainy season should not be too large, and should be completed segment by segment and segment by segment; when the rainfall is heavy, the earthwork construction should be stopped in a large area; For the foundation soaked by rainwater, necessary work such as excavation and backfilling should be done to restore the bearing capacity of the foundation; important or special projects should be completed before the rainy season.

3. To prevent the slope from being washed away by rainwater, nail wire mesh can be added to the slope, and 50cm of fine stone concrete can be applied; the slope can also be covered with plastic sheets;

4. In order to prevent the foundation pit from being soaked, drainage ditch and water collecting well should be made in the foundation pit and necessary drainage force should be organized during excavation; the pool and basement located at the bottom should be carefully considered during construction. If the pre-consideration is not careful, after pouring and pounding, in the event of heavy rain, it will often cause the basement and pond to float up. ​​

5. When excavating foundation trenches or pipe trenches in rainy period, attention should be paid to the stability of the slope. If necessary, slow down the side slope or set up supports. The inspection and control of side slopes and supports shall be strengthened during the construction of space frame engineering; supports shall be provided for excavated foundation trenches or pipe trenches. ​​

6. The earthwork backfilled before the rain should be rolled in time to form a certain slope on the surface, so that the rainwater can be automatically discharged.

To sum up, in the construction of space frame structure, we must pay attention to the influence of the unique influencing factors in the rainy period, so as to solve unique problems in the rainy period, and strengthen the safety and stability of the space frame structure.

Space frame industry knowledge: https://www.safsteelstructure.com/news-center/

Instability analysis of steel space frame structure

 1. The steel space frame structure is divided into overall instability and local instability. Most of the overall instability is caused by local instability. When the slenderness ratio of the compression part or the bending part exceeds the allowable value, the stability will be lost. It is affected by many objective factors, such as load changes, initial defects of steel, and different supporting conditions etc.. Support is often ignored by designers or builders, which is also one of the reasons for the overall instability.

2. Due to the different positions of the hoisting points, the force of the pipe of the steel truss or space frame structure may change, resulting in instability; the overturning, collapse or deformation of the scaffold is mostly caused by insufficient connecting rods and no support.

Therefore, when designing the steel space frame structure, it should be designed by technical personnel with rich work experience. It should not be taken lightly and try to avoid the above-mentioned hidden dangers. Our company has more than 10 years of rich experience in the field of steel structure, professional and technical personnel, professional equipment, and won the trust of many customers.

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How to avoid deformation of bolt ball space frames

   The bolt ball space frame uses the bolted ball as the node between the steel rods, which plays the role of support and leverage. The bolted ball space frame is usually used outdoors, and it will be deformed due to some external factors. So how should we avoid the deformation of the bolt ball space frame?

1. The front page needs to be tied up during transportation, and some more support points should be added. Try to choose wood for padding, so as to avoid deformation of columns, beams, tie rods and other connecting parts during transportation.

2. Use two-point hoisting when loading and unloading the bolted ball net frame. If the bolt ball net frame is too long, a pole can be used and the lifting point can be appropriately increased.

3. When the bolted ball space frame is stacked, the number of stacked layers can be reduced. At the same time, it is necessary to appropriately increase the supporting points to prevent the bolted ball space frame from being deformed by compression.

Connectors such as bolted ball space frames often experience extrusion and deformation. In order to reduce the occurrence of these situations, you can learn more about the above information. Only in this way can the deformation of the connecting parts be avoided and reduced, and the utilization rate of the bolted ball space frame can be improved.

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7 advantages of space frame structure

 Most of today's industrial warehouses are built with a space frame structure. Why does the space frame structure have such magic to attract these owners? I have summarized 7 advantages to share with you:

1. Anti-earthquake disaster and anti-storm: the anti-seismic level is above level 8, and it can withstand level 11 storm (wind force 140km/h).

2. Anti-rust treatment and anti-corrosion: light steel structures generally use hot-dip galvanized steel plates and V-type connectors as the frame. Good rust resistance, high compressive strength and long service life. No distortion, no deformation, no erosion, firm structure. The design scheme of the steel structure has a service life of 50 years.

3. Safety and fire prevention.

4. Thermal insulation: The thermal insulation function is further improved. Building environmental protection and energy saving can reach 65%, exceeding the national regulations on building environmental protection and energy saving.

5. Protect the ecological environment.

6. Good sound insulation performance: meet the sound insulation requirements of workshops.

7. Space frame steel structure industrial warehouse are widely used in outdoor spaces: power plants, cement plants, clinker plants, etc. will build coal storage, cement or clinker warehouses.

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Roof panel installation steps of steel structure space frame

1. Check whether the purlins are installed correctly, and whether the steel prefabricated components are sprayed or not;

2. Before installation, according to the layout diagram of corrugated steel plate, classify and stack according to the type and specification. The corrugated steel plate faces upwards, the lap edge faces the installed roof edge, and is placed along the steel roof truss beams and laid manually;

3. The steel structure grid roof panel is laid at the eaves of the roof. In the whole process of installation, the straightness of the cornice line is used as the benchmark, and the positioning of the pull line is checked. The dislocation difference between the ends of the two adjacent panels should not be greater than 8 mm, and the slope of the roof panel is perpendicular to the datum point of the cornice;

4. Start from one side of the roof,put the first piece of roof board installation and location line.Pave the first corrugated steel plate, and fix it with screws after inspection;

5. After the first corrugated steel plate is fixed in place, install the next corrugated steel plate. When installing, place its lap edge on the front corrugated steel plate accurately. In order to ensure the installation position is accurate, clamp it with the previous corrugated steel plate with a tooling fixture, fix both sides of the corrugated steel plate, and then fix it with screws;

6. The length of the longitudinal lap of the corrugated steel plate is not less than 250mm, the lap joint is located at the purlin of the roof, the lap joint is sealed with glue and a row of waterproof rivets, and then fixed with screws;

7. Install the corrugated steel plate in place using the above method. For every 4 pieces of corrugated steel plate installed, check the flatness on both sides of the profiled steel plate. If there is any deviation, adjust it immediately and accurately measure the total width of the fixed profiled steel plate. , measure it once on both the upper and lower sides to ensure that no fan shape appears in the installation part of the corrugated steel plate;

8. After installing a certain number of roof bottom plates, start the installation of roof panel supports, and fix the supports and steel purlins with screws. Then lay insulation cotton, and ensure that the insulation cotton is installed tightly;

9. The installation of the steel structure space frame roof panel is basically the same as that of the thermal insulation cotton. When a piece of thermal insulation cotton is installed, a roof panel is installed. The installation method of the roof panel is the same as that of the roof bottom plate.

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Precautions for installation of steel structure space frame in autumn and winter

 1. According to the average temperature specification, the data map of the installation sequence of the steel components is compiled, and the installation is carried out in strict accordance with the sequence during construction.

2. When assembling the space frame components, expand and assemble from the inside to the outside according to the order specified by the process, and do a test to determine the shrinkage value of the weld that needs to be reserved during the assembly at low temperature.

3. When the steel components are made at normal temperature and installed at low temperature, the shrinkage of the components should be fully considered according to the difference in ambient temperature, and technical measures to adjust the deviation should be taken during construction.

4. The columns and main beams installed at negative temperature should be corrected immediately. After the correct position correction, they should be permanently fixed immediately. The components installed on the same day should form a stable space system.

5. When the high-strength bolted joint is installed, the friction surface of the component shall not have snow and ice, and shall not be in contact with dirt, oil and other stolen goods.

6. When using steel cables to hoist steel components, anti-slip spacers should be added, and the gusset plates that are lifted at the same time as the components, and the fixtures and other items that the installer needs to use are securely tied with ropes.

7. When the steel structure space frame is installed on site, it is necessary to build a protective shed in case of rain and snow or when the wind speed is above 6m/s.

Installation steps of the lower chord of the flat steel space frame structure

 1. Familiarize with the drawings before installation, recheck the size and quantity of each component to be installed, and place each component in the order of installation to facilitate the installation of the steel space frame structure.

2. Before installation, check the quality of the threaded fasteners, clean the screw holes and threaded fasteners, and screw them in after they are clean. The high-strength bolts should be tightened in place to ensure that the downward deflection of the entire space frame structure is not affected.

3. According to the numbered positions of the rods and balls on the drawing, install the lower chord balls and rods in the first span to form a longitudinal plane grid, and tighten the high-strength bolts.

4. After installing the support in the first span, align the axis and centerline of the column top. Use a level to correct the elevation if there are errors.

5. Arrange the temporary fulcrums according to the required elevation of the bottom chord to ensure the elevation position of the bottom string.

The temporary fulcrum can be made of on-site scaffold steel pipes, so that the lower chord grid of the first span can pass through the temporary fulcrum.

SAFS Steel Structure Official Website: https://www.safsteelstructure.com/

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