Reasons for loosening of space frame bolts in gas station

A gas station is a place where gasoline is added to motor vehicles. The appearance must be more conspicuous and appealing to consumers.Gas stations with good appeal can attract a large number of customer resources and increase profits for gas stations.The shape design of the gas station using the space frame structure is generally very neat and simple. The canopy and the column constitute the main body of the structure.The area around the canopy is usually decorated with aluminum slabs and light box cloth. The upper plan is usually covered with color steel plates, and the lower plan is set for lighting fixtures. Ceiling are not required. If suspended ceilings are required, aluminum gussets are generally used. Many gas station space frame have loosening of space frame bolts during the installation period or a period of time after installation. There are many factors that lead to this type of situation.All of us must deal with it according to specific circumstances.

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

1. Installation by non-professional staff: The space frame construction team is still not professionally trained, and feels that it is caused by tightening the sleeve. Many non-professional staff, who have not undergone professional training, seem to be tightened, but in fact they are not tightened in time. Perhaps the construction site has not been able to deal with the problem in time, but it will loosen after a period of application, which is very dangerous.

2.  After the roof installation was completed, the sleeve was loosened after delivery, the rubber support was rusted, and the components were damaged. After this problem occurs, it will seriously harm the installation of the space frame design scheme. The bearing structure is changed. It is very easy to cause safety hazards and safety accidents.

If you have any of the above problems, I suggest to stop and repair it in all directions.Each component of the space frame is carefully inspected, and repairs are carried out purposefully. In serious cases, it must be disassembled and installed again, and painted again.

The space frame structure has a small steel content, and the parts are all prefabricated components of the factory. The installation is convenient and the construction period is very short, which is more suitable for rushing to the construction period.

What is the H-beam commonly used in steel structure workshops?

Steel structure workshop H-shaped steel is a kind of economical section and high-efficiency section with more optimized cross-sectional area distribution and more reasonable strength-to-weight ratio. Because the section and the English letter "H" is the same name. H beam has been widely used for its advantages of strong bending resistance, simple construction, cost saving and light structural weight. H-shaped steel is mainly used in industrial factory, civil construction, municipal engineering, etc., and light H-shaped steel is very suitable for the manufacturing of containers, mobile houses, and various garages.

1. The expression method of hot-rolled H-beam:

H-beams are divided into three types: wide-flange H-beams (HK), narrow-flange H-beams (HZ) and H-beam piles (HU).

 

The expression method is: height H width B web thickness t1 wing plate thickness t2, such as H-beam Q235, SS400 200200812, it is expressed as a wide flange H-beam with a height of 200mm, a width of 200mm, a web thickness of 8mm, and a wing plate thickness of 12mm. The grade is Q235 or SS400.

Advantages of hot rolled H-beam:

H-shaped steel is a new type of steel for economic construction. H-shaped steel has economical and reasonable cross-section shape and good mechanical properties. During rolling, each point on the cross-section extends more uniformly and has low internal stress. Compared with ordinary I-beams, it has the advantages of large section modulus, light weight, and metal saving, which can make buildings The structure is reduced by 30-40%; because the legs are parallel inside and outside, and the ends of the legs are right-angled, they can be assembled into components, which can save welding and riveting work by up to 25%. It is often used in large buildings (such as factory buildings and high-rise buildings) that require large intercepting capacity and good cross-sectional stability, as well as bridges, equipment foundations, and supports.

The Hot-rolled H-beams can reasonably allocate the height-to-width ratio of the cross-section size according to different purposes, and have excellent mechanical properties and superior use performance.

2. Welding H-beam production process

Steel plate-automatic slitting-assembly-automatic submerged arc welding-flaw detection-flange correction-web correction-end surface processing-sand blasting and rust removal-painting. The automatic submerged arc welding production line is controlled by a microcomputer to ensure the dimensional accuracy of the H-shaped steel produced, and the quality of the welds meets the national standards. The steel structure building has a simple and lightweight structure, which expands the internal space of the building, saves steel, and has a short installation period. The roof and walls are made of color profiled steel plates, which makes the building more beautiful.

H-beam weight (2*b*t2+h*t1-2*t1*t2)*7.85*L/1000000

H-beam surface area (4*b-2*t1+2*h)*L/1000

The above is the H-beam commonly used in steel structure workshops.

Five support methods of space frame structure

The support methods of the space frame structure include peripheral support, point support, combination of peripheral support and point support, two-sided and three-sided support, etc.

As the roof of a large-span building, the space frame structure should firstly meet the requirements of the building layout and the use function of the building. This structure has greater spatial rigidity and is more sensitive to the rigidity and stability of the supporting member. From a mechanical point of view, the support of the frame structure can be divided into two types: rigid support and elastic support.The former means that there is no vertical displacement under load, there can be horizontal displacement, or no horizontal displacement. It is generally suitable for the space frame to be directly placed on a column, wall, or reinforced concrete beam with greater rigidity;The latter generally refers to the situation where the free side of the three-sided support space frame is equipped with anti-beam support, truss support, and cable support.

When it is not allowed to set up columns on one or both sides of the space frame at the expansion end of industrial plants, hangars, hull workshops, gymnasiums, etc., the space frame needs to be designed in a form that supports three sides and one side is free. Mixed support is suitable for large steel column industrial plants, warehouses, exhibition halls and other buildings.

Reasons for bolt loosening after installation of space frame structure

When the space frame structure is installed, or a period of time after installation, the high-strength bolt sleeves of the space frame structure are loosened. There are many reasons for this situation, we need to analyze and deal with the specific situation:

1. Installation by undocumented workers: space frame workers have not received professional training, and they feel that they are tightening the sleeve. Many non-professional workers have not dealt with it well, and may not find the problem in time on the spot. However, it is very dangerous to loosen after a period of use.

2. After the roof panel was installed, the sleeve was loosened, the support was rusted, and the rod was damaged during use. These will seriously affect the carrying capacity of the space frame design, change the force structure, and cause hidden danger accidents.

For the above two problems, I personally suggest to stop using it and check and repair all aspects. In particular, each component of the space frame must be carefully checked and repaired in a targeted manner. The serious problems must be disassembled and reinstalled, and then repainted.

Picture from: safsteelstructure.com

How to inspect the steel structure space frame engineering coatings

In modern society, people's living standards have been greatly improved, and their tastes are getting higher and higher. There are also certain regulations for the aesthetics of engineering buildings. There are also certain regulations for common coatings for large-scale engineering buildings. Now let’s introduce how to test the construction coatings for steel structure space frame engineering. 

Inspection quantity: 10% of the number of prefabricated components shall be sampled for inspection, and similar prefabricated components shall not be less than 3.

Inspection method: check with a gray knife.

Do not miscoating, leakage coating, coating should not molt and rust.

Inspection quantity: all

Inspection method: vision inspection

                                          Picture from: safsteelstructure.com

Steel structure space frame inspection method: check the quality standard certification materials, Chinese label and test report of the product.

The types, specifications, characteristics, and quality of raw materials such as steel structure fireproof coatings, paints, paint thinners and epoxy curing agents should comply with the current standards of our country's product implementation standards and design plans.

The anti-rust treatment of the surface of the steel frame structure before painting shall comply with the relevant laws, regulations, specifications and design plans of the current standards. The surface of the treated stainless steel plate shall not have rust, weld bead, weld slag, oil stain, dust, water and burrs, etc. When the design scheme is not specified, the derusting grade of the steel frame structure surface should meet the requirements.