











The beam-column joints of Prefab House are mainly connected by bolt welding. However, bolted joints are recommended for fabricated steel structures. The advantage of bolted connection (weld-free connection) is that the installation speed is fast and the construction quality is easier to control.
1. The construction period is short. Generally, the first floor of Prefab House can be built in three or four days, and it only takes one or two days. Steel structure residential systems are mostly manufactured in factories and installed on-site. The amount of on-site work is greatly reduced. Therefore, the construction period can be greatly shortened, and the noise and dust generated during the construction, as well as the consumption of on-site resources and various on-site expenses are correspondingly reduced. Compared with reinforced concrete structures, the construction period can generally be shortened by one-half, the investment benefits can be brought into play in advance, capital turnover can be accelerated, and construction costs can be reduced by 3%-5%.
2. Good seismic performance. Because the steel of Prefab House is an elastically deformable material, it can greatly improve the safety and reliability of the house. The steel structure has high strength, good ductility and light weight, which can greatly improve the mechanical performance of the structure, especially the seismic performance. Judging from the situation after the earthquake at home and abroad, the number of collapsed steel structure residential buildings is very small.
In line with the development direction of building energy efficiency. Prefab House uses steel as the frame and thermal insulation wallboard as the enclosure structure, which can replace clay bricks, reduce the amount of cement, sand, stone, and lime, and reduce the damage to non-renewable resources. On-site wet construction is reduced, and the construction environment is better. At the same time, steel can be recycled and reused, and the environmental pollution during construction and dismantling is small, and its energy saving index can reach more than 50%, which belongs to the green building system.
The application of steel structure in Prefab House has opened up a new application market for my country's steel industry. It can also drive the research and application of related new building materials.
Steel-finished house is generally a residential building constructed with factory-made, economical steel profiles as a supporting work and new lightweight, heat-conserving, heat-insulating and high-strength wall materials as a home. The industrialisation of the steel building house refers to the use of steel construction houses as the final product. Through socialized mass production, the process of investment, development, construction, construction and customer service of steel dwellings is centralised and unified into an overall organisational form. The industrialization of the steel building house is the development trend of the steel building house.
Knowing this, do you also need to order a Prefab House? Qingdao Xinguangzheng Steel Structure Co., Ltd. is committed to providing various Prefab Houses with high quality for all customers from all over the world.
1. The positioning axis and supporting surface elevation of the foundation are out of tolerance:
The positioning axis of the foundation and the elevation of the supporting steel cylinder exceed the allowable deviation.
The reasons are as follows:
There are errors and deviations in foundation survey control network, foundation survey setting out and elevation finding.
The foundation formwork is not firmly set up, the pouring concrete blanking is too high, and the concrete is vibrated and impacted, which makes the formwork displacement and causes the datum line deviation.
Or the use of steel ruler, theodolite, level without calibration, there are errors.
Or construction wrong drawings, axis wrong, without strict inspection.
Or if the foundation bearing surface is not plastered and leveled twice, the concrete will shrink and sink.
Or the embedded steel plate (or support) is not fixed.
Because the foundation positioning axis and bearing surface are out of tolerance, the column installation axis and bearing elevation will be out of tolerance, which will affect the quality of the whole structural steel construction installation project.
Avoiding measures:
(1) The accuracy of basic survey control network, instruments and measuring tools used for basic survey setting out and leveling shall be accurate. Before use, they must be checked or verified by the measurement department. If problems are found, they shall be adjusted in time to prevent errors or accumulated errors, resulting in axis and elevation exceeding the allowable deviation.
(2) The foundation formwork for steel structure construction must be firmly supported with sufficient strength and rigidity. When pouring concrete, cutting and vibrating, it is necessary to prevent from striking the formwork and causing displacement. In the process of concrete pouring, the positioning axis and elevation shall be checked regularly with measuring tools or suspension lines. If any deviation is found, the pouring and vibration shall be stopped, and the work shall be carried out after reinforcement and adjustment. Before the final setting of concrete, the surface of foundation concrete shall be plastered and leveled twice. For the embedded steel plate or bearing, the elevation and levelness shall be aligned twice, and the concrete at the bottom shall be dense. The steel plate or support of foundation support column shall be provided with necessary fixing devices to ensure correct position and elevation.
(3) When the elevation and levelness of the steel plate or support on the vertical and horizontal axis of the foundation and column bearing surface are out of tolerance, measures shall be taken according to the degree of deviation. When the out of tolerance is not serious, it can be solved by shifting the column base, reaming and packing the base plate. If the deviation is serious and cannot be adjusted, it should be studied with relevant departments to work out a feasible correction scheme before treatment.
2. Foundation anchor bolt thread damage:
The foundation anchor bolt thread is damaged, and the nut cannot be screwed and tightened during the column installation.
The causes of bolt thread damage are as follows:
Anchor bolts are impacted or improperly kept during transportation, loading and unpacking, resulting in serious thread corrosion.
Or the bolts were not protected after burying and were damaged by outside.
Or the bolt is used as electric welding zero line on site, and the thread is damaged due to arc burn.
Or the bolt is used as the binding point of the pulling force of the traction rope.
Due to the damage of bolt thread, it is impossible to screw in nuts to fasten steel columns and other components, which affects the transmission and stability of structural force.
Avoiding measures:
(1) When the anchor bolts are transported, packed and unpacked, the thread protection shall be strengthened. After being smeared with industrial vaseline oil, they shall be wrapped and bound with plastic film to prevent thread damage and corrosion. And should be stored separately, should not be mixed with other parts and components, so as to avoid mutual impact damage thread.
(2) After the anchor bolt is embedded, it shall not be used as the fulcrum of bending processing, the neutral line of electric welding machine, or the binding point of traction force. When lifting components, proper operation shall be carried out to prevent the thread from being damaged by horizontal lateral impact force.
(3) The screw thread of the bolt has been damaged, and the following treatment methods can be adopted: when the damaged length of the screw thread does not exceed its effective length, the steel file can be used to trim the screw thread, so as to smoothly screw in the nut. When the length of thread damage of local foot bolt exceeds the specified effective length, the length of original thread section can be cut by gas cutting; Then, with the same material and specification as the original bolt, one end of the bolt is processed into thread, and the butt end section is made into 30º-- 45º. After butt welding with the lower end of the groove, the corresponding diameter specification and length of the steel casing sleeve into the joint, welding reinforcement. After casing reinforcement for steel work in construction, the diameter of the bolt will be larger than that of the base plate, which can be solved by appropriately enlarging the diameter of the base plate.
3. The setting of mortar base plate of column base does not meet the requirements:
The mortar base plate of column base is set randomly, and the elevation, levelness and position do not meet the design and specification requirements.
The reasons are as follows:
The surface of the foundation is not treated and leveled, so that the base plate can not bear the force smoothly, and the surface is uneven and uneven;
The base plate is not reasonably arranged according to the stress requirements, so that the base, base plate and foundation can not bear uniform pressure, so that the settlement of base slurry is uneven, and the elevation and levelness can not meet the requirements.
If the setting of open base plate does not meet the requirements, it can not transfer the load evenly, which will reduce the mechanical performance of the column and affect the stability of the superstructure.
Avoiding measures:
(1) In order to make the base plate group transmit the force to the foundation smoothly, the base plate should be closely combined with the base slurry on the foundation surface. The uneven foundation surface shall be chiseled and leveled.
(2) The location and distribution of the base plate should be correct. Generally, according to the stress area of the steel column base plate, the base plate, the base plate and the foundation should be arranged in the center of the steel plate and the stress concentration position on both sides or near the two sides of the anchor bolt, so that the base plate, the base plate and the foundation can fully bear the pressure load, and bear the force uniformly together to avoid partial bias Concentrated stress or deformation of the base plate occurs when the anchor bolts are tightened.
(3) The area of the base plate directly bearing the load should meet the needs of the stress, which should be determined by calculation, and the area should not be too large or too small. Too large will cause waste, too small will cause local concentrated overload of foundation and affect the overall and uniform stress of foundation. The thickness of the base plate is generally within the range of 4 ~ 25 mm, each group is no more than 3 pieces. The base plate has a 10 ~ 12 mm thick steel plate, the length of the base plate is 100 ~ 300 mm, and the width is 50 ~ 120 mm. When setting the mortar, use non shrinkage cement mortar with strength not lower than 30MPa. As the steel column is mainly installed with cushion plate to adjust the elevation and levelness, the elevation and levelness shall be found when grouting, and the allowable deviation shall comply with the specification, and the supervision shall be strengthened. Before the base plate is grouted, the rust, oil stain and burr on the surface of the base plate shall be cleaned, so that the base plate can be firmly combined with the concrete when grouted and grouted; The length of the base plate group exposed to the outside of the base plate edge is about 10 ~ 20 mm.
4. Before the installation of steel column, the foundation is directly installed without inspection:
Before the installation of steel column, the axis and elevation of the foundation, the position and elevation of the anchor bolt and the concrete quality of the foundation are not checked in advance, so the installation is carried out directly. In this way, there may be out of tolerance without repair, which will cause structural installation difficulties, increase the steel column installation stress and affect the installation accuracy, and even cause quality hazards.
Avoiding measures:
Before the installation of steel column, the positioning control line, foundation axis, elevation, anchor bolt position, elevation and concrete quality of foundation shall be pre checked. If the deviation is found, measures shall be taken to correct and adjust to the allowable deviation range of the specification. For elevation inspection, the measured data shall be compared with the pre inspection data of steel column size and elevation, and the error of the two shall be eliminated when the support base slurry pad or anchor bolt nut is adjusted. The allowable deviation of foundation support surface, anchor bolt position and base slurry pad shall meet the requirements of the specification. The quality of foundation concrete shall be dealt with in accordance with relevant regulations.
5. Don't check the dimension of steel members, deal with deformation and quality defects before installation
Before the installation of the structure, the external dimensions of the steel members are not checked, and the deformation and quality defects of the members are handled.
Although the steel components have passed the quality inspection before they are processed in the factory, they may fail to be inspected, or new deformation and damage may occur in the transportation and stacking of the components. If the review is not carried out before the installation, these problems can not be dealt with in time before the installation, which will affect the installation quality of the steel structure and cause installation difficulties or permanent quality defects.
Avoiding measures:
Before the installation of steel members, the steel members shall be carefully checked in advance:
It includes checking the model and quantity of the component, the overall dimension of the component, the relevant dimensions between the supporting surfaces and the installation holes, and marking the datum line of the axis of the component. Check whether the component is deformed, and correct and repair the deformation error if there is any.
Whether the connecting plate, splint and other accessories of the component are complete and whether the position and size are accurate. Inspect whether the surface quality of the welding area of the component and the friction surface of the high-strength bolt connection meet the requirements and whether it is polluted.
Whether the member nodes are complete and whether the center of gravity of main components is marked.
Whether the surface of the component is polluted, whether the paint falls off, etc.
Pre inspection records of components shall be made; For the components with deformation and defects exceeding the allowable deviation, they shall be corrected and repaired on the ground before installation, and can be installed after they are qualified.
6. The perpendicularity of steel column installation is out of tolerance:
The verticality deviation of steel column exceeds the allowable value in design or code
When the steel column is manufactured, the deformation control measures are not taken or the bending deformation is not straightened.
Or the length of the column is large, the rigidity is poor, and the elastic or plastic deformation occurs under the action of external force.
Or due to the unreasonable hoisting technology and procedure, the roof panel is bent and deformed under the action of temperature, wind and external force.
Or there is deviation in the span size of the roof truss, the external force is used to force the connection during the installation, resulting in the over deviation of the verticality of the steel column.
This will lead to the deflection of the steel column and affect the bearing capacity and stability.
Avoiding measures:
(1) Anti deformation measures shall be taken for assembly and welding of steel column, and the deformation during fabrication shall be corrected in time. When transporting and stacking steel columns, the supporting points should be appropriate to prevent bending deformation under the action of self weight. The out of plane stiffness of long column is poor, so the lifting point should be selected at 2 / 3 of the total length of the column to prevent deformation. If the span size of steel roof truss exceeds the deviation, it should be corrected before installation to prevent forced connection and bending deformation of column body.
(2) When the steel column is hoisted to the foundation plane in place, the vertical and horizontal axis above the column base plate should be aligned with the foundation line, so as to prevent the deviation of span size, which will lead to the horizontal tension or thrust when the column head is installed and connected with the roof truss, so as to make the column body bending and deformation, and carry out appropriate control.
(3) When the roof slab is hoisted after the connection and installation of the steel column and the tail-stock, it should be carried out symmetrically and synchronously from the edge of the two slopes in the center of the top chord to the middle, so as to prevent the bending deformation of the steel column caused by the lateral concentrated pressure generated by the one slope. Without the permission of the design, the steel column and other connected components shall not be used for horizontal dragging or vertical hoisting of heavy components and equipment, and the column bending deformation or damage to the connecting structure shall be prevented.
(4) If the bending steel column is elastic deformation, it can be restored to its original state after the external pressure is removed; If it is plastic deformation, it can be corrected by adding temporary support above or at the top of the bending part of the steel column before correction, so as to reduce the load-bearing gravity, and then fixing one side reaction frame at the bending part, and using jack for correction. If the rigidity of the steel column is large, it can be corrected by heating the bending convex surface with oxyacetylene flame, and then applying jacking force.
7. Steel column installation height is out of tolerance:
Height dimension or relative position of steel column after installation (±) The elevation dimension is out of tolerance, which makes the difference between the total height of each column and the height deviation of the bracket.
The reasons are as follows
Foundation elevation is incorrect or deviation occurs.
The length and dimension of steel column during the production stage are out of tolerance.
Or when the foundation elevation is adjusted and treated during installation, it is not combined with the actual length (height) of steel column, which will cause the positive or negative difference of the height dimension or elevation dimension of the steel column after installation.
Because of the over tolerance, it is difficult to install and adjust the components connected with it, which makes it difficult to correct and takes time.
Avoiding measures:
(1) During the foundation construction, the elevation size should be strictly controlled to ensure the accuracy of elevation. The elevation dimension of the upper surface of the foundation shall be adjusted according to the actual length of the steel column or the elevation dimension of the bracket supporting surface, so as to make it consistent with the height and elevation dimension of the steel column after installation.
(2) During the manufacturing process of steel column, the length and size (including the total length and the length of each position specified in the design, the length and size within the allowable positive and negative deviation range, and the positive excess value not allowed) and the correct size of the total length and bracket of the steel column without contact point shall be strictly controlled. The latter can be adopted to weld the column body first, and the column base plate and column head plate shall not be welded temporarily, In case of out of tolerance, adjust before welding the base plate or upper column head plate of the column, and finally weld the base plate and column head plate of the column.
Introduction of Qingdao Jiaodong International Steel Structure Building Airport
Qingdao Jiaodong International Airport (comprehensive transportation center and parking building) project is constructed by open cut method. The buried depth of the structure bottom is about 2.5m, and the wall wrapping surface is about 3.5m * 0.85m.
The column is made of Φ 850 * 25 / φ 700 * 16 straight seam concrete-filled steel tubular column, and the upper and lower columns are welded by variable diameter (φ 850 ~ φ 700). The total height is about 30 meters, and the total weight is about 20 tons. It is transported to the construction site in 17m + 13m sections. Each steel pipe column is made of 25 mm or 16 mm thick steel plate.
Factory processing assembly with an error of ± 2mm to meet the requirements, the construction site using a 250t crane for installation.
Prefab House refers to a building where parts and components produced in a factory are assembled and connected at the construction site. Steel structure prefabricated buildings refer to steel structure components produced in factories and assembled and connected at the construction site.
Different countries have different understandings and practices of the housing system, but Prefab House generally refers to the main project of the house. Different residential products are formed due to the selection of different structural materials, structural types and construction methods, and constitute a number of corresponding residential products ranging from design to The complete technology of construction. The steel structure residential building system uses the steel structure form as the basis for the classification of the building system and becomes a branch of the building system.
The material of Prefab House has good homogeneity and isotropy, which is an ideal elastic body, which is most in line with the basic assumptions of general engineering mechanics; the material has good plasticity and toughness, can have large deformations, and can well withstand dynamic loads; construction period is short ; It has a high degree of industrialization and can be used for specialized production with a high degree of mechanization; it has high processing accuracy, high efficiency, and good airtightness, so it can be used to build gas tanks, oil tanks, and transformers.
In the future, the steel structure of Prefab House should study high-strength steel to greatly increase its yield point strength; in addition, new types of steel should be rolled, such as H-shaped steel (also known as wide flange steel), T-shaped steel and profiled steel plates, etc. The needs of large-span structures and super high-rise buildings.
(1) Light weight and high strength. Due to the use of steel as the load-bearing structure and new building materials as the enclosure structure, Prefab House generally uses steel structure to build residences that weigh about one-half of the weight of reinforced concrete residences, which reduces the weight of the house and reduces the cost of basic engineering. Since the building area occupied by the vertical force-bearing member is relatively small, the use area of the house can be increased. At the same time, because the steel structure residence adopts a large bay and large depth column network, it provides residents with a large space that can be flexibly separated, which can meet the different needs of users.
(2) The degree of industrialization is high and meets the requirements of industrialization. Most of the structural components of Prefab House are made in factories, which are easy to install and suitable for mass production. This has changed the traditional way of housing construction and realized the transformation from "building houses" to "manufacturing houses". Promoted the transformation of the housing industry from extensive to intensive, and at the same time promoted the development of productivity.
Qingdao Xinguangzheng Steel Structure Co., Ltd. has worked on the production of Prefab Houses for several years. You can find the best Prefab House in this company.
The project of steel structure hangar for African market constructed by Xinguangzheng Group has been completed smoothly. The Niger hangar project need comprehensive consideration, and a severer designing demand. The client has also a higher requirement for the portal.
Given the strictly demand for portal, Xinguangzheng has offered the most specialized blue print as well as installation services, and has finished the project excellently. We have thus gained our clients' trust and support.
Xinguangzheng will continuously seek for technical breakthroughs and new products, offer integrated settlements, and provide our clients with best products and best services, to give our clients more happiness.
Qingdao Activa Group is the largest outdoor leisure products R & D and production enterprise in the world. It has established factories and branches in 14 countries and regions. Currently, it has five hundred year brands in its industry, and 1820 patents at home and abroad. The first phase project of Qingdao Activa Group, which is contracted by our company, has a total construction area of over 80000, which is the general contracting project.
Agricultural steel building has low cost, short construction time, and less pollution. Therefore, it has become the best choice for new-style construction.
Structural parts: material, surface roughness, tolerance, surface treatment, straightness (or radian)
Connection: hole position deviation, bolt grade; welding method, welding standard, welding material; air tightness, non-destructive testing, liquid penetration testing, etc. are required
Overall structure: verticality, horizontality, etc.
Packaging: packaging materials, packaging methods
Storage: ambient temperature, ambient humidity
Transportation: loading and unloading, placing in vehicles, placing in containers, etc.
Fire protection technology. One of the most critical issues in agricultural steel building is the application of fire protection technology. The fire resistance rating of light steel structure houses is level 4. For light steel structure residential buildings, fire-resistant gypsum boards are pasted on both sides of the wall and the ceiling of the floor. For ordinary firewalls and household walls, 25.4 mm thick (1 inch) gypsum boards are used to protect them to meet the 1-hour fire protection requirement. The glass fiber filled between the wall columns and the floor joists also plays an active role in protecting fire and heat transfer.
Sound insulation technology. The agricultural steel building is filled with glass wool between the inner and outer walls and the floor joists, which effectively prevents the audio part transmitted through the air. For the impact sound transmitted through the solid, the following construction is performed: the partition wall is composed of two wall columns. There are two walls with intermediate spaces; for the small keel used to fix the gypsum board for the suspended ceiling, an elastic structure with small cut grooves is used to effectively reduce the transmission of structure-borne sound between floors.
If an agricultural steel building is damaged, we must immediately recognise and remedy the problem. The main factors of steel structural damage are:
(1) the structural viability of agricultural steel buildings is insufficient due to changes in load, overdue service and changes in rules and regulations;
2) The components of agricultural steelworks are deformed, twisted, damaged, deformed, etc., due to various accidents; which results in a weakening of the cross-section of the component, a twisting of the rod and a tearing of the connection;
(3) deformation, cracking and retardation of agricultural steel components or connections due to temperature differences;
4) The agricultural steel structure corrodes due to the erosion of chemical substances and electrochemical corrosion leads to a weakening of the cross-section of the steel structure;
5) Other include errors in design, production, construction and illegal use and operation during the service period.
There are three main technical reinforcement measures for agricultural steel construction:
1) Cross-section defences: Apply the element locally or over the entire length of the element with steel and connect it to a whole to carry the force together;
2) Change the calculation diagram: add additional supports, adjust load distribution, reduce cutting force level, force displacement of static indefinite structural support and reduce peak voltage;
3) Pre-tensioned cable method: use high-strength cables to strengthen the weak links of the structure or to improve the overall durability, stiffness and stability of the structure.
Qingdao Xinguangzheng Steel Structure Co., Ltd. has been developing agricultural steel buildings for many years, and is known as "the national brand leader in the Chinesesteel building industry". Therefore, customers can choose their products with confidence.
The light steel structure of commercial steel building is a structure composed of steel materials, and each component or part is connected by welding, bolts or rivets.
commercial steel building is mainly used for low-rise or multi-storey buildings: the prefabricated wall panels are transported to the construction site by special vehicles, hoisted by cranes, connected with the foundation by anchor bolts and connectors, and the wall panels are connected by screws and connectors, and then the light steel floor is installed. The light steel floor is composed of floor beams, profiled steel plates Steel wire mesh and concrete. The construction of the main structure can be completed by constructing the upper floor according to the construction method of one floor and finally installing the roof. The system is applicable to buildings with 6 floors and below. It has the advantages of high assembly rate, short construction cycle, earthquake resistance and typhoon resistance, thermal insulation, large use area in the sleeve, no exposed beams and columns, and recyclable materials.
1. The construction period is short. The construction period of commercial steel building can be shortened by more than 50%;
2. The project quality is stable. The quality of parts and components produced in commercial steel building factory is more stable, which solves many common quality problems of on-site construction technology and human errors in on-site construction, and ensures the project quality;
3. Energy saving and environmental protection, less construction pollution. commercial steel building adopts energy-saving technology, which greatly improves the performance of house thermal insulation and sound insulation, and improves the living comfort of the building. According to statistics, the prefabricated construction method can save about 50% water, 70% wood and 70% construction waste;
4. Integrated decoration, which is carried out simultaneously with architecture, structure and electromechanical design. commercial steel building completes the pre functional conditions, pipeline installation, wall decoration and component installation in place at one time, which not only ensures the decoration quality, but also avoids the repeated waste and secondary pollution of secondary decoration.
1. Variability
The construction quality problems of commercial steel building will continue to evolve and change with external changes and the extension of time, and quality defects will gradually manifest. For example, the welds of steel components cause cracks in the welds that did not originally have cracks due to changes in stress: delayed cracks can occur due to the activity of hydrogen in the welds after welding. In addition, if the component is subjected to long-term overload, the steel component will be bent and deformed under the arch, which will cause hidden dangers.
2. Frequent
When faced with the relatively unfamiliar construction and construction techniques of steel structures, managers and technicians engaged in construction must be very careful and trained before they can take up their posts.
Knowing this, do you also want to order a commercial steel building? Qingdao Xinguangzheng Steel Structure Co., Ltd., which has been a Chinese pioneer in commercial steel building for many years. Their skilled staff can use the best solution for anything, particularly when a custom product is required.