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.
(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.
(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.
(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.
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.
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.
(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.
(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.
Residential steel building is lightweight and high-strength. For buildings of the same weight, the steel structure has a small cross-section and a large net height, which can save building height. The number of layers of steel structure is more than that of concrete, which not only increases the building area, but also brings good economic benefits.
What are the advantages of Residential steel building?
What raw materials should be used for the walls of Residential steel building?
What is the roof system of Residential steel building?
1. Superior seismic performance
Compared with traditional residential structures, Residential steel building is a flexible structure and has a lighter weight. Therefore, buildings with the same fortification intensity and the same site will bear less seismic force, and the earthquake disaster caused by them will be weakened accordingly. The use of steel in the earthquake zone Structural housing will reduce casualties and property losses, with considerable comprehensive benefits.
2. Flexible layout and increased effective use area
Residential steel building adopts steel structure, which can realize large span under the premise that the cross-section is not too large, which makes the building function very flexible and can be flexibly arranged according to the needs of residents, which is conducive to meeting the needs of modern homes and adapting The needs of the modern housing market. Moreover, the steel structure is adopted, the cross-section of the beams and columns is small, and the use area of the residents is increased at the same time.
Residential steel building's steel frame system, steel frame-support system, steel frame-concrete core tube (shear wall) system outer walls can be filled with small concrete block walls, autoclaved lightweight aerated concrete slabs, and prefabricated reinforced concrete walls Board, steel wire mesh frame polystyrene sandwich panel, fiber cement external wall hanging panel, polyurethane composite external wall panel, metal surface embossed composite panel, etc. The inner wall can be made of glass fiber strong gypsum hollow board, fiber cement board infusion (foam concrete) wall, light composite wall board, etc.
1. The flat roof of the Residential steel building adopts steel beams (I-beam, C-shaped steel), prefabricated reinforced concrete roof panels, and thermal insulation and waterproof layer.
2. The sloping roof of Residential steel building adopts portal frame, truss, light steel keel truss (bracket), I-shaped (or C-shaped) and steel purlin, colored cement tile, colored steel plate tile and colored asphalt tile roof. Thermal insulation and waterproof layer should also be used in the slope roof. The thickness of the insulation layer is determined by thermal calculation and meets the requirements of energy-saving design standards.
It is an important choice in residential building construction. A good Residential steel building starts with the best engineering staff, and Qingdao Xinguangzheng Steel Structure Co., Ltd. is always ready to help you meet your technical and practical requirements.
Steel building accessories include steel components such as steel wall trusses, steel trusses, steel windshields, steel roof trusses, steel beams, steel columns, steel supports, etc.; specific requirements are corresponding to the quota sub-items, which are calculated separately, and different sub-items are set.
What are the advantages of using Steel building accessories to build houses?
What are the common Steel building accessories on the market?
Why do Steel building accessories need to be fireproofed?
1. The total weight of the building using Steel building accessories is light, which is about half of the concrete structure. At the same time, it can greatly reduce the foundation cost of the house.
2。 The construction speed of Steel building accessories is fast, and the construction period is at least one third shorter than that of the traditional residential system. A 1000 square meter building can be completed in only 20 days and five workers.
3. The house with Steel building accessories has good environmental protection effect. This is because the consumption of sand, stone and ash is greatly reduced during the construction of the residential buildings built by Steel building accessories. The materials used are mainly green, 100% recycled or degraded materials. When the buildings are demolished, most of the materials can be reused or degraded without causing garbage.
4. Steel building accessories is welcomed by everyone for its flexibility and abundance. Large bay design, indoor space can be divided by multiple schemes, which can meet the different needs of users.
5. The use of Steel building accessories meets the requirements of housing industrialization and sustainable development. The steel structure is suitable for mass production in the factory with a high degree of industrialization. It can integrate advanced finished products such as energy saving, waterproof, heat insulation, doors and windows, and apply them in a complete set, integrating design, production and construction, so as to improve the level of construction industry.
1. u-shaped bracket
The u-shaped bracket is also one of the important accessories of Steel building accessories. The bracket is used for the connection between the ground and the main material. In addition to the fixing function, the u-shaped bracket can also balance the overall bearing force.
2. Fishing rod bracket
The fishing rod bracket of the steel structure frame is a single-unit fixing device accessory, which is used for the initial fixing of the single-unit room.
The temperature resistance of steel is poor, and many of its properties change with the rise and fall of temperature. When the temperature reaches between 430-540℃, the yield point, tensile strength and elastic modulus of the steel will drop sharply, and the load-bearing capacity will be lost. Steel building accessories must be maintained with refractory materials.
Qingdao Xinguangzheng Steel Structure Co., Ltd., as a Chinese pioneer in producing Steel building accessories, can ensure the products’ quality and the after-sales service
Introduction of Zhongjie era Steel Structure Frame Overpass Project
Zhongjie Times Square overpass project is the first Cross Street overpass project in Pingdu. The whole project is composed of three overpasses. The length of the straight overpass on the east side is 56.3 meters and the width is 5 meters. The length of the straight overpass on the west side is 49 meters and the width is 5 meters. The diameter of the main bridge surface of the central circular overpass is 56 meters. The narrowest part is 6.5 meters and the maximum width is 12 meters. The construction of the overpass on Hongqi Road can avoid the interference of people and vehicles To improve the road capacity, and effectively solve the problem of efficiency and safety of a large number of people crossing the street.
After completion, it will become the most characteristic commercial block with urban flavor in the main urban area of Pingdu City, as well as the landscape landmark and cultural landmark of Pingdu.
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.
Plant Introduction of Sri Lanka Prefabricated Steel Structure Material for Power Plant
Project Brief Description: Lakvijaya power plant, the largest power plant in Sri Lanka, is the company that undertakes the steel structure materials of wind barrier project. Designed and fabricated by Qingdao Xinguangzheng Steel Structure Co., Ltd. in 2019.
Qingdao Xinguangzheng steel structure Group is a public company with 1200 workers, 360000 ㎡ non-dust workshop, 25 years experience, CE, ISO9001, ISO9712, ISO3834, BV, SGS certificated, one hour reach Qingdao port, our company, as a manufacture, this is how we keep good quality and competitive prices for global valued customers.
We provide steel building design, farm house design, manufacture and installation service.
The China Flower Fair, which was founded by our company in 1987, is the largest, highest-grade and most influential national flower event in China, and is known as the "Olympic" in the Chinese flower industry. Nowadays, there are many characteristic flower and tree fairs all over the country, such as China (Xiaxi) flower and tree Festival, China Flower Trade Conference, Zhengzhou International Flower and horticulture exhibition, Xiaoshan flower and tree Festival, Shuyang flower and tree Festival, etc.
Qingdao Xinguangzheng Company suppiler of Steel Structure Conference center of China flower Expo.
1200 workers, 360000 ㎡ non-dust workshop, 25 years experience, CE, ISO9001, ISO9712, ISO3834, BV, SGS certificated, one hour reach Qingdao port, our company, as a manufacture, this is how we keep good quality and competitive prices for global valued customers.
We provide steel building design, farm house design, manufacture and installation service.
As the strategic decision to develop energy-saving and land-saving housing and construct a conservation-oriented society is further deepened and housing industrialization has become a new growth point for the world’s economic development, the development of residential steel building will be the only way for housing industrialization.
1. residential steel building's structural system is diversified
Many structural systems that can be used for steel structure residences have been developed, steel frame structure, steel frame-support structure, frame-tube structure (steel frame, concrete internal simplified), frame-shear wall structure (shear wall can be steel plate, concrete Or concrete with built-in steel support), light steel structure and staggered truss structure system can all be used as the structural selection of residential steel building.
2. The project cost of residential steel building is slightly higher than that of concrete or equivalent
The cost of steel structure material is higher than that of concrete, but its construction period is short, the use area is large, and the number of floors can be increased under the same conditions. The project cost of residential steel building is slightly higher or equivalent to concrete, and the actual economic benefits are significant, making residential steel building It has become the first choice for high quality and low price, and the best choice for replacing masonry structure houses in the future.
residential steel building has a high technological content. The structure itself is often the architectural expression. The performance and craftsmanship of the steel structure is not only a necessary means to realize the image conception, but also has a significant impact on the architectural image, which determines that the structural conception is the success of the image conception. The key is whether or not. The progress of science and technology and the change of aesthetics will inevitably make steel structure buildings continue to expand their expression vocabulary and seek development. residential steel building sets aside the elements of style, starts from structural rationalism, and absorbs the essence from modern and traditional styles. In the future, it will be possible to create high-quality steel structure buildings with organic integration of technology and art.
The residential steel building of the design structure and the stability calculation of components must cooperate with each other to make them consistent. The consistency between structural calculation and structural design has always been a problem that everyone pays attention to in structural design. For the joint connection requiring to transfer bending moment and not, sufficient stiffness and flexibility shall be given to it respectively, and the eccentricity of members shall be minimized for frame joints, which are often considered by designers when dealing with structural details. However, when it comes to stability, there are often structural requirements or special considerations different from strength. For example, in terms of flexural strength of simply supported beams, the requirement for fixed hinge support is only to prevent displacement and allow rotation in the plane. However, the above requirements are not enough when dealing with the overall stability of the beam. The support shall also be able to prevent the beam from twisting around the longitudinal axis, and allow the beam to rotate in the horizontal plane and the beam end section to warp freely, so as to meet the boundary conditions adopted for stability analysis.
Qingdao Xinguangzheng Steel Structure Co., Ltd. has been committed to providing customers with residential steel buildings and perfect after-sales service so that customers can invest easily, use them with confidence, and have no worries.