Introduction of Pakistan Prefabricated Steel Structure Construction Chemical Factory
Project Area: 4225 ㎡
Project Finished Time: Built in 2019-2020
Project Location: Lahore
Project Detail: Multi-story steel structures
Project Total Steel weight: 600 tons.
Company information of Pakistan Prefabricated Steel Structure Construction Chemical Factory
A brief introduction to you about our company first, then you can contact me if there is suitable project in the future.
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.
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.
Due to the increase in steel production in the world, many new factories have begun to introduce industrial steel buildings which can be divided into factories for light and heavy steel structures. Steel structures are industrial and civil engineering installations made of steel.
What are the reasons why people opt for industrial steel building?
What are the advantages for people who opt for industrial steel building?
What is the order of installation of industrial steel buildings?
The industrial steel building uses a highly efficient and energy-saving system, has a respiratory function and can regulate the dry humidity of the inner air; The roof has a ventilation function that can form a flowing airspace over the house to ensure the ventilation and thermal drainage requirements within the roof.
The industrial steel building is completely dry and is not affected by the environmental season. With a building of about 300 square meters, only five workers and 30 working days can complete the entire process from foundation to decoration.
The material of the industrial steel buildings can be recycled to 100% which is really green and free of pollutants.
All industrial steel buildings use high-efficiency energy-saving walls that have good heat storage, thermal insulation and sound insulation and can achieve 50% energy-saving standards.
1 industrial steel building has a wide range of applications: it can be used in factories, warehouses, office buildings, stadiums, hangars, etc. to be used. It is suitable not only for single-storey and wide-stretched buildings, but also for the construction of multi-storey or high-rise buildings.
2 The construction of the industrial steel building is simple and the construction time is short: all the components are pre-fabricated in the factory, the construction site only needs to be simply assembled, which greatly shortens the construction time. For a 6000-square meter building, the basic installation can be completed in just 40 days.
3 The industrial steel building is durable and easy to repair: the steel building constructed by universal computers maintains rough weather conditions and requires simple maintenance.
4 industrial steel building is beautiful and practical: steel construction has simple and smooth lines with a modern sense. The coloured wall panels are available in a variety of colours, and the walls can also be made of other materials, making them more flexible.
5 The cost of industrial steelmaking is reasonable: the steel structure has a low weight, reduces the cost of the foundation and is fast in construction. It can be completed and put into service as soon as possible. The overall economic benefits are much better than those of concrete construction.
Installation procedures for industrial steel buildings:
Steel column installation → installation of support between columns → temporary installation of steel crane beams → roof beams, roof supports → correction and fixation of steel crane beams → maintenance of structural installation.
Qingdao Xinguangzheng Steel Structure Co., Ltd. strives to provide top-quality industrial steel buildings with reasonable prices, efficient production time, and the most professional customer service.
Industrial steel building mainly refers to that the main load-bearing components are composed of steel. Including steel column, steel beam, steel structure foundation, steel roof truss (of course, the span of the plant is relatively large, and they are basically steel structure roof truss now), steel roof. Note that the wall of steel structure can also be maintained by brick wall.
What should be taken into account in the day-to-day maintenance of industrial steel buildings?
What are the arrangements for the planning of industrial steel buildings?
What should be taken into account when selecting industrial steel building?
After the installation of our industrial steel building, the owner is not allowed to change its structure privately, not to remove screws and other parts, and not to increase or reduce the partition wall. If you need to change a part, you need to negotiate with the manufacturer. It is up to the manufacturer to decide whether it can be changed. After approximately three years of use, the steel structure must be maintained with colour to give the building beauty and safety. industrial steel buildings are connected by steel construction components, so electrical devices such as wires should be insulated by cable channels in order to avoid accidents involving electric shocks.
The maintenance of industrial steel buildings is closely linked to the durability of the steel structure. That is why the industry pays enough attention to it. If you have problems with maintenance and maintenance, you should contact a professional steel construction manufacturer for help.
1. Insurance: Avoid rain water from the outside entering the metal roof of the industrial steel building. Rainwater enters the metal roof mainly through overlapping joints or knots. In order to achieve the function of the centrifuge, it is necessary to use a sealing disc at the screw connection and to make a concealed fixation. Use sealants or welds on the top of the plate. Best use a long board to remove the overlap. Close water-tight treatment for bleeding.
2. Fire protection: The metal material does not burn in the event of fire and the flame does not penetrate the metal roof plate.
3. Wind pressure resistance: industrial steel building can withstand the maximum local wind pressure and the metal roof plate is not removed by negative wind pressure. The wind resistance depends on the strength of the metal roof plate and the fixing seat and the density of the fixing seat.
Sound protection: industrial steel building prevents sound transmission from the outside to the inside or from the inside to the outside. Fill the metal sheet with sound insulation material (mostly insulated cotton) and the sound insulation effect is expressed by the sound intensity difference on both sides of the metal sheet. The sound insulation effect depends on the density and thickness of the sound insulating agent. Note that sound insulating agents have different locking effects on sounds of different frequencies.
After reading these words, do you also want to order an industrial steel building? If necessary, you can contact Qingdao Xinguangzheng Steel Structure Co., Ltd., which is an advanced industrial steel manufacturer.
Nowadays, more and more industrial parks prefer to build workshop, warehouse, office and other buildings by steel structures. Why are steel structures so popular with the public? It is mainly due to the four excellent functions of steel structure "light, fast, good properties and economical".
1. Light: The steel structure has the characteristics of light weight and excellent stress function.
Steel has the smallest ratio of density to strength compared with concrete and wood. For example, the weight of steel roof trusses is only 30% or even 25% of the same concrete roof truss under the same load and strength conditions. The weight of the steel structure house is about 50% of the reinforced concrete house, but the usable area is about 4% higher than that of the reinforced concrete house.
The steel structure is prefabricated in the factory then bolts contacted installation on site. It has the characteristics of mass production of large pieces and high-level precision of finished products, which effectively shorten the construction period and reducing the cost to give high investment returen. Compared with the construction period of reinforced concrete structure engineering, the steel structure is only 1/3 to 1/2 of the reinforced concrete structure under the same conditions .
3. Good properties: The steel structure has good properties and high reliability.
Steel has uniform of texture, isotropy, large elastic modulus, good plasticity ,good resistance and is an ideal elastic plastic body. Therefore, the steel structure will not suddenly break due to occasional overloading or partial overloading, it can adapt to the oscillating load, and the calculation model can reflect the mechanical properties of the steel well, so the analysis is accurate and reliable.
The cost of steel structure is higher than concrete structure from the raw materials only, but the construction speed of steel structure is about 50% faster than concrete structure, which will save a lot of time and cost. The steel structure is more than 50% lighter than the overall weight of the concrete structure house, so that the cost of basic treatment and transportation will be reduced. Building is a systematic project includes many items, such as planning, manufacturing, transportation, installation, maintenance and management. Therefore, from the overall point of view, the steel structure is more cost saving.
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.
Step 1: Cutting
Cut steel plate into pieces and connections by flame cutting machines (CNC, Semi-automatic flame cutting machines). Long strips will be used as web and flange plate, connections will be used as connected, reinforced or stiffening plate.
Step 2: Assembly
Combine web and flange plate together through H-beams assembly machine, make tack welding. Keep the web plate in the middle line, do not be off the center line.
Step 3: Gantry automatic submerged arc welding
Make welding by gantry submerged arc welding machine. Make sure the welding sequence and reduce the welding deformation.
Step 4: Flange plate of straightening
Start straightening on welding-finished H steel beams by straightening machine.
Step 5: Connections process
Make holes on connected pieces by drilling machines. Make sure the hole size and precision.
Step 6: Welding
Welding with CO2. Make sure the weld quality without welding flaw.
Step 7: Shot blasting
Make shot blasting on steel profiles. Make sure the blasting grade and quality.
Step 8: Spray painting
Painting or other anti-corrosion surface treatment.
Step 9: Package & Loading
Pack steel structure profiles on steel pallet, which will be easy for loading, transportation and unloading jobs.
Industrial steel building is easy to move and recycle without pollution. These are stronger than traditional workshops, and the walls of the steel structure workshops can also be filled with bricks, which are completely load-bearing. All future plant constructions will be steel structure plants. Here we are going to introduce the steps of installing Industrial steel building.
What are the raw materials used in industrial steel building?
What is the main installation process of industrial steel building?
What is the production and installation process of industrial steel building?
In addition to iron and carbon, the raw materials of industrial steel building also contain other elements. Divided into permanent elements; occasional elements; hidden elements and alloying elements. The common elements are manganese, silicon, sulfur, and phosphorus. Incidental elements are due to the different origins of ore (there are intergrowth ore mixed with iron) and scrap steel as raw materials, such as copper, titanium, vanadium, rare earth elements, etc., are brought into steel during smelting and process operations. The cryptic elements refer to non-metal elements with a small atomic radius, such as oxygen and hydrogen. Alloying elements refer to elements specially added to change the composition, such as chromium, nickel, tungsten, molybdenum, vanadium, etc.
Carbon steel (referred to as carbon steel) is an iron-carbon alloy with a carbon content of more than 0.0218% and less than 2.11%. Because carbon steel has good mechanical properties and process properties, and is large in output and low in price, it is a metal material that is widely used in mechanical engineering. However, carbon steel also has some shortcomings, such as low hardening energy, poor temper softening resistance, and low yield ratio. The strength potential of carbon steel cannot be fully utilized even after heat treatment. In order to meet the continuous development of modern industry and science and technology, alloy steel was developed.
Foundation → production and installation foundation is divided into (foundation ground survey → foundation excavation → embedded screws → foundation casting → later foundation grouting → outdoor water dispersion → outdoor drainage ditch (some factory design indoor drainage ditch or cable ditch suggestion Completed simultaneously with installation)→Enclosure masonry→tiling tiles, etc.)
The production and installation are divided into (processing production→component painting→structural pre-assembly→steel component hoisting→main structure adjustment→purlin installation→door and window column installation→gutter downpipe installation→steel component painting (some are fireproof, some are Anti-corrosion, according to design requirements) → roof panel (some with steel mesh, some with insulation layer, completed at the same time) → wall panel installation → door and window installation → water supply and drainage installation → electrical equipment installation)
Qingdao Xinguangzheng Steel Structure Co., Ltd., as a Chinese pioneer in producing Industrial steel buildings, can ensure the products’ quality and the after-sales service.