The full name of MDC is"MONDU DA CASA (home world)", which is constructed by Qingdao Xinguang Zheng Steel Structure Co., Ltd. This is a comprehensive shopping center centering on the theme of "happy home". This theme is the same as the enterprise mission of "benefiting the society, achieving employees and making customers happier". In addition to "home world", she has another interpretation of "modern decoration Center".
MDC is located in KIKUXI section of Luanda expressway, surrounded by Angola national stadium, high-end residential villa area, Brazil nursery garden, and Luanda commercial pedestrian street under planning, with superior geographical environment and convenient transportation.
"MDC home world" shopping center covers an area of about 30000 square meters. Relying on the global procurement network, it has gathered kipor generator 4S shop, furniture store, building materials store, home furnishing store and home appliance store. The categories include building materials pipe fittings, wood, floor tiles, paint and coating, decorative lamps, kitchen and bathroom equipment, hardware tools, electrical and electrical materials, gardening supplies, cloth furniture, home appliances, etc., and also auxiliary It is one of the most comprehensive "one-stop purchasing" centers for home furnishings in Luanda with public service facilities such as business office, catering, leisure and entertainment, bank, etc.
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.
Industrial steel building is a great invention. All components are prefabricated in the factory, and the site only needs to be assembled simply, thus greatly shortening the construction period. For a building of 6000 square meters, the basic installation can be completed in only 40 days.
What should I pay attention to when using Industrial steel building?
What are the reasons why Industrial steel building is used more and more widely?
What are the steps involved in the general process of Industrial steel building installation?
1. Industrial steel building construction has strict requirements for construction measurement. When the steel structure workshop stops the structural calculation, the mechanical model is very clear, and the size change has an obvious influence on the model. Therefore, during the manufacturing and installation stages, construction measurement is a more important issue. For example, inaccurate blanking will result in deformation of components; failure to be placed in place during installation will affect the load-bearing effect of the environmental characteristics of the construction site welding of steel structure workshops.
2. The steel of Industrial steel building has the characteristics of thermal expansion and contraction, and it is sensitive to weather, temperature and other conditions during the installation process. Industrial steel building welding has its own special technical requirements. In practice, when natural conditions cannot meet the work requirements, manual measures are often taken to create conditions for construction, such as preheating of welding rods and preheating and heating of steel plates. If the size of the steel structure factory building changes greatly during the construction process, the temperature is too high or too low will affect the accuracy of the device.
3. The Industrial steel building is easy to rust and has poor fire resistance, so it needs to be painted and maintained. Paint the steel structure factory building fireproof coating on the exterior of the Industrial steel building to play the role of fire protection and heat insulation maintenance, to prevent the steel from rapidly heating up in the fire and reducing its strength, and to prevent the steel structure factory building from losing its support ability and causing the building to collapse.
The grid structure of Industrial steel building has the advantages of reasonable stress, large stiffness, light weight, single member and convenient fabrication and installation. In recent years, it has been widely used in public and industrial buildings with large span and large column network. It can be used not only for roof structure, but also for floors, walls and special structures.
1. The main structure hoisting of Industrial steel building,
2. Secondary structure installation of Industrial steel building,
3. Installation of roof panel and insulation layer of Industrial steel building,
4. Wall maintenance and installation,
5. Finally, the detailed structure of Industrial steel building.
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Ⅰ. Steel column installation for steel structure construction
1. Installation sequence of steel column:
① Foundation setting out → ② binding → ③ hoisting → ④ correction → ⑤ final fixation
2. Installation method of steel column:
(1) Setting out:
A. Elevation control:
In this structural steel construction project, iron parts and "middle bars" are controlled according to the depth of concrete cup mouth, the elevation of steel column bottom and the embedded elevation in the center of the bottom of the cup mouth during the construction of concrete foundation (φ30 steel bars), the elevation of top surface of "middle reinforcement" is based on the elevation of steel column bottom, and the elevation error of iron parts is controlled in ± Within 1mm.
To ensure the steel column is embedded in the foundation accurately and firmly φ On the 30 "middle reinforcement", weld a steel plate with thickness of 20 at the bottom of H-shaped steel column, as shown in the figure below.
When installing structural steel column, clean the foundation cup mouth first, and check the embedded elevation control "middle reinforcement" in the foundation（φ The actual height of 30 steel bars) is not necessary because the elevation embedded in the foundation construction has been controlled precisely, and no additional iron pad is needed. The method is simple, fast and efficient for the treatment of steel column feet. The construction is fast and the force is reasonable. When the column is lifted, it can be adjusted freely in several directions when the elevation is unchanged.
B. Before installation, the vertical and horizontal axis reference lines of the foundation plane shall be placed on the top of the cup mouth by woodworking ink bucket as the installation and positioning line of steel column.
(2) Column binding and hoisting:
A. after the steel column enters the site, the steel column shall be arranged according to the position of the lifting plan, and the model and number shall be checked to see if they are correct. The plane position of steel column after entering the site is shown in the following figure.
B. Before the column is lifted, a horizontal line shall be drawn with red oil paint 2300mm upward from the bottom of the column, so as to recheck the plane elevation datum before and after the installation and fixation.
C. the column installation belongs to vertical hoisting. In order to keep the suspended column drooping and facilitate the positioning, the binding point is determined at the lower part of the bracket. In order to prevent the sharp edges and corners of the column edge from damaging the lifting rope during hoisting, the rubber belt of the old car is used to separate and cover the edge and corner lifting rope. Pay attention to binding firmly and easy to remove.
D. temporary steel ladder and high-strength bolt installation fixture of working platform shall be bound on the steel column.
E. in order to avoid the free swing of the suspended column, hemp rope should be used to tie the upper part of the column bottom as a restraint rope and adjust the direction.
F. according to the site conditions, the rotation method is adopted for hoisting
After the preparations before hoisting are ready, the trial hoisting shall be carried out first. When the height of the steel column is 200 mm above the ground, the hoisting shall be stopped to check whether the rigging is firm and whether the crane is stable. After confirming that there is no problem, the crane can be directed to slowly lift, rotate to the top of the cup mouth, and then slowly descend. When the distance between the bottom of the column and the design position is 40-100 mm, adjust the two datum lines of the column body and the foundation to reach the accurate position, direct the crane to descend to the position, and temporarily fix the column with steel wedge (or wood wedge) and wind rope to remove the hook.
• Key points of rotation method:
The method of lifting the column by rotating the column around the column base is called rotation method, as shown in figure a below. When the column is hoisted by rotation method, in order to improve the hoisting efficiency, when the steel column enters the site, the binding point of the column, the center of the column base and the center of the cup foundation should be placed on the arc with the crane stop point as the center and the distance from the stop point to the binding point (i.e. the turning radius of the column), as shown in Figure B below.
The steel column hoisting is shown in the figure below:
(3) Preliminary correction of column:
The column should be corrected on the side with large deviation first, and then on the side with small deviation.
A. The correction of column generally includes plane position, elevation and perpendicularity.
B. When the steel column is hoisted in place, it is one-time alignment, and generally it does not need plane re correction. For the elevation of the column, it has been used before hoisting φ The embedded "middle reinforcement" can accurately control the elevation. Generally, it only needs to be checked, and it does not need to be corrected. Therefore, the steel column correction is mainly to correct the verticality and recheck the elevation.
C. In this project, the perpendicularity of the column is observed, and two theodolites are used for measurement and correction.
• First, place the theodolite on one side of the column, align the longitudinal center wire with the baseline of the column base, and then fix the screws of the horizontal plate.
• Measure the center line of the column and observe from bottom to top. If the vertical center line is aligned, that is, the column is vertical. If it is not aligned, the column shall be adjusted until it is aligned with the longitudinal center line of theodolite.
• Measure the horizontal line in the same way so that the center line of the other side of the column is perpendicular to the horizontal axis of the baseline. After the column is accurately positioned, the column can be fixed.
• Verticality correction of steel column: distance adjusting screw rod and steel wedge are used. Due to the small contact surface of the long side of the column, the base plate is set during the construction. The details are as follows.
The manufacturing dimension of steel wedge is shown in the figure below:
(4) Final alignment and fixation of steel columns:
After the steel column is hoisted in place, the column correction mainly involves the adjustment of elevation and the correction of verticality; The correction method can use tools such as wind rope, Jack, crowbar and steel wedge (or wooden wedge) to apply vertical force and lateral force of pulling, jacking, supporting and prying to the steel column.
Adjust the verticality, positioning axis and elevation of the column. After confirming the correctness, the gap between the steel column and the foundation cup mouth shall be poured with C40 fine stone concrete. The expansive high strength grouting material is preferred.
Ⅱ Protection of site components:
1) The unloading of components shall be careful to prevent damage and prevent collision and extrusion between members.
2) The members shall be stacked in order at the designated site, and the number of layers stacked by steel beams shall not exceed 3 layers to prevent the members from squeezing and deformation.
3) Before hoisting, oil, sediment and dust on the surface of the components shall be cleaned.
Ⅲ The placement of components and the requirements for the site
1) When unloading, the components are unloaded directly near the installation position and within the radius of rotation of the crane. Mark the number clearly with a clear color pen to facilitate lifting.
2) The components are placed in order in the site, and a certain gap is reserved between adjacent components to facilitate binding.
3) The site shall be solid and flat, and the components shall not be polluted due to rain and snow, and the vehicle with 30 ton level can be walked.
Ⅳ Steel structure building installation
Preparation before hoisting of steel column:
Before hoisting the steel column, the cable wind rope shall be tied to the column body. The lifting point shall be at the bracket position, and the double wire rope shall be set up and down, and the snap ring can be checked to be qualified before entering the next work. Before hoisting the steel column, the positioning axis, foundation axis and elevation, cup opening size and the height of the bottom standard of the steel column must be inspected and handed over and accepted. The number, outline dimension, screw hole position and diameter of the steel column shall be comprehensively reviewed. After confirming that it meets the requirements of design drawings, draw out the installation center line and the lower end elevation line of the steel column.
Ⅴ Steel column hoisting
(1) installation method of steel column
Before lifting the steel column, the wooden board shall be fixed at the column foot to prevent damage to the column foot and other structures.
Special hoisting steel wire rope is used for steel column binding. Wood or rubber sheet shall be used to prevent damage to the steel column.
The steel column is installed by a 25t truck crane. When the steel column is lifted, the crane shall hook and rotate the arm while lifting the steel column to make the steel column vertical away from the ground.
(2) positioning adjustment and temporary fixation
When the steel column is lifted to 200mm above the base cup mouth, it will be stable, and it will fall slowly at the base cup mouth. Avoid hitting the concrete edge of the foundation cup mouth during falling. After implementation, use special angle ruler to check, adjust the steel column to make its positioning line coincide with the foundation positioning axis. Three people are required to operate the adjustment, one person moves the steel column, one person helps to stabilize and the other person conducts the test. The positioning error is controlled within 2mm.
(3) when adjusting the elevation of the steel column, place the pad iron at the bottom of the cup foundation, use the level to super level the bottom plate elevation of the steel column as the top elevation of the pad iron, so that the elevation after the steel column is in place can meet the design elevation requirements, mark the elevation datum point on the column body, and then use the level to measure the installation elevation after it is installed in place.
(4) the verticality of the steel column shall be preliminary adjusted by the level ruler. Then two theodolites are used to observe from both sides of the column at the same time, and the adjustment is carried out by relying on the cable wind rope. As shown in the figure below:
Diagram of verticality adjustment of steel column
(5) after the adjustment, use eight iron wedges to position the gap between the bottom of the steel column and the base of the cup mouth, and then spot weld the column to make it stable.
Ⅵ Steel beam installation
Steel beams must be stacked in order on site for this steel work in construction. Sleepers must be placed in the middle of each layer of steel beams. Two lifting points for steel beam hoisting are selected on both sides of the center of gravity of the steel beam. The two lifting points should be 800mm away from the support and the middle of the span, and the distance between the two lifting points should be increased according to the length of the steel beam.
To ensure safety and prevent the sharp edge of the steel beam from cutting the steel wire rope, the steel wire rope shall be protected, the angle of the sling shall not be less than 450, and the steel beam shall be directly tied and rolled with the steel wire rope or lifted with a special fixture.
Before hoisting the steel beam, install the safety rope on the steel beam. When hoisting, hang two sliding ropes at both ends of the steel beam. Two people pull two sliding ropes respectively. The hoisting speed of the steel beam must be slow. In order to ensure safety, personnel should not stand directly under the beam. The cloth bags specially used for placing high-strength bolts are put on both ends of the steel beam. When the steel beam is hoisted above the position, the steel beam is put in place. The falling speed of the steel beam is controlled at 3m / min. two installers are arranged at both ends of the steel column head to prepare for the installation of the steel beam. When the steel beam is close to the in place position, two installers should hold the upper flange of the steel beam with their hands respectively, drag the steel beam to the in place position, and prepare to install the high-strength bolts.
Ⅶ Installation of retaining structure and support corner brace
1) Installation of roof purlin: when the main structural steel forms a frame section, the roof purlin is hoisted to the main beam of the roof with a crane and installed manually. The purlin can also be manually pulled onto the roof with a white synthetic rope for installation. After the installation of purlin, the purlin support is installed in time.
2) Wall purlin installation: when the main structure forms a frame section, the construction personnel stand on the scaffold platform and pull the wall purlin to the installation position with white comprehensive rope.
3) Corner brace installation: after the main body is welded, the corner brace is connected.
Ⅷ Measurement and correction of steel column
Verticality correction of steel column
When the steel column is installed and corrected, two theodolites are set up on the control line with 90 degree translation of 1 meter each other, and the theodolite operators observe the small steel ruler on the top of the column, measure the deviation of the steel column and direct the correction.
A. Control the verticality of the steel column between the first hoisting joints.
B. Steel column calibration is divided into four steps:
initial calibration during initial tightening; Re-calibration before final tightening; Tracking and monitoring during welding process; Final result measurement after welding.
The perpendicularity can be roughly controlled with a long level before the initial tightening, and it can be accurately corrected after the frame is formed. After welding, retest shall be carried out, and the measurement results shall be compared with those at final tightening, so as to be the basis for the next construction.
C. Verticality measurement method of C steel column
Initial correction: the perpendicularity of the steel column is preliminary adjusted with a level ruler.
Accurate correction of steel column perpendicularity: one column grid is used as an installation section for the hoisting of the main frame until the hoisting of three continuous complete sections is completed
After the whole is formed, the measurement correction can be inserted. Two theodolites are used to observe from both sides of the column at the same time, and the wind rope is used for correction and adjustment.
Ⅸ Steel structure survey
2) Elevation control of steel column
Based on the elevation reference point of the plane layer where the steel column is located, the deviation value of the horizontal elevation of the steel column is measured with the level gauge and the correction is directed.
3) Steel beam measurement
After the steel column is hoisted and corrected, the +1.00m control point shall be measured to each steel column according to the site level as the basis for vertical transfer of elevation and the elevation of beam installation; Pop up the center line of the steel beam on the surface of the steel beam.
The control axis is measured to the column body to control the beam position offset; The accuracy of beam elevation is controlled according to the control point of column elevation. Set up theodolite on the floor platform, and then look at the cross angle to the axis of the corresponding beam. Aim at the center line of the upper surface of the beam to the other end with theodolite to see if the number coincides with the axis of the beam.
Calculation of survey and lofting data
In this project, the computer automatic query method is used to calculate the survey and lofting data. The specific steps are as follows:
1) The establishment of data model
Firstly, according to the design coordinates and the dimension relationship of each building in the design drawing, the building, building axis, control line to be lofted and so on are drawn in AutoCAD according to the proportion, and the data model is established.
2) Survey and lofting data query
After drawing the survey loft data model, the survey loft data such as the angle and distance between the known basis (axis control pile, lofted axis, etc.) and the control line to be lofted are queried by using the command of dist of AutoCAD.
3) Advantages of computer automatic query
The method of computer automatic query is used to obtain the required measurement and positioning data. It is not only convenient to calculate, but also has high precision. The distance precision can be set to 0.1mm, 0.01mm, and the angle precision to 0.0 ", 0.00" or higher according to the actual situation.
Ⅹ Construction of high strength bolt
1. Preparation before installation
1) Test and inspection of high strength bolt
Anti slip coefficient test
The project adopts class 10.9 large hexagon high-strength bolts. The anti slip coefficient test of high-strength bolts shall be conducted by taking the most representative thickness of the plate in the project for test, and three groups shall be made.
The size of the specimen plate is as follows:
Axial force test
Randomly select the bolts to be installed at the construction site, and 8 sets of bolt pairs are selected for re inspection in each batch.
2) Transportation and storage of high strength bolts
The form, size and technical conditions of high-strength bolt connecting pair shall be manufactured and supplied by the manufacturer according to batch, with factory certificate and high-strength bolt connection pair, which shall conform to the provisions of national standards gb1228-1231-84 and gb3632-3633-83. High strength bolts with large hexagon for steel structure
The connecting pair consists of a bolt, a nut and two washers. The combination of use shall meet the national standards, and the high-strength bolt connection pair shall be supplied with storage and transportation in the same batch.
The high-strength bolt connecting pair shall be installed and placed lightly during loading, unloading, transportation and storage to prevent the packing box from being damaged or damaged.
Storage of high strength bolt warehouse
1. the high-strength bolt connection pair shall be cleaned according to the specification, batch number and supply date of the packing box, and shall be kept in the indoor warehouse, and the accumulation shall not be higher than 3 layers. The indoor moisture-proof, long-term dry, rust and dirt contamination shall be prevented, and torque coefficient shall be prevented from changing. The bottom layer shall be more than 300mm above the ground level.
2. when installing on site, the quantity of high-strength bolts required on the day shall be issued. The rest should be kept properly. Do not put it in disorder, damage the thread, and be contaminated with dirt.
3. before using the long-term storage high-strength bolt connection pair, a comprehensive quality inspection shall be conducted again. If any abnormal phenomenon is found after unpacking, the inspection standard shall be conducted according to the relevant provisions of national standards gb1228-1231-84 and gb3632-3633-83. It can be used after being qualified.
3) Construction management of high strength bolts
1. Construction Manager
When carrying out the construction of this high-strength bolt, the high-strength bolt manager shall be determined first to be responsible for the project management, quality management and guidance of the construction personnel.
2. weather management (climate conditions)
In principle, no operation shall be carried out during rainfall and snowfall. If rain or snow fall occurs during operation, the speed shall be accelerated to lock the unfinished ones
3. friction surface management
Before tightening, the friction surface shall be inspected first. If there are any attachments to reduce bearing capacity of friction surface, such as rust, oil, paint and residue, metal brush, sandpaper and oxygen acetylene flame shall be used for removal.
4) Construction of high strength bolts
1. final tightening of temporary bolts
Before inserting high-strength bolts, temporary bolts shall be used to tighten the connection tightly, if the materials of the connection parts are bent or warped, they shall be corrected.
If the difference of holes is within 2mm, it can be corrected by cutter.
If the difference of holes exceeds 2mm, reasonable treatment methods such as replacement of panel shall be adopted based on consultation with management personnel, and gas cutting and reaming are not allowed.
2. high strength bolt insertion
The nut and gasket of high-strength bolt shall pay attention to the installation direction, and install according to the following figure.
When inserting bolts, pay attention not to attach rust, dust, oil, etc. to the bolts. In addition, do not force into the bolt hole during construction to avoid damaging the thread.
3. initial tightening
After the temporary fixing bolts are locked, confirm the compactness of the components.
After initial tightening, mark with white marker through bolt nut, gasket and component.
When using the inspection wrench, although the torque value can be confirmed by the contact sound, it is easy to over tighten if the mechanism continues to apply force, so it should be noted.
4) Final tightening
After initial tightening, use special fastening wrench to lock until the neck is broken.
In principle, the bolts inserted on the same day shall be screwed out on the same day.
Qingdao Xinguangzheng Steel Structure Group completed Qingdao Haier Yungu Supporting School Project on August 31, 2022.
Agricultural steel building components or parts are usually connected by welds, bolts or rivets. Because of its light weight and simple construction, it is widely used in various fields of agricultural production. Steel structure is easy to rust. Generally, steel structure needs to be derusted, galvanized or painted, and it needs to be maintained regularly. Here we are going to know more about the Agricultural steel building.
What are the architectural characteristics of Agricultural steel buildings?
What are the appearance characteristics of Agricultural steel building?
What should be paid attention to when constructing Agricultural steel building?
1. Industrialization of the production process. The steel structure is only connected by high-strength bolts. It also has the advantages of quick installation and return on investment.
2. Use high-quality materials with high toughness and plasticity. The quality is safe and reliable.
3. It also has the advantages of flexible design and decoration, low cost, and various colors.
The Agricultural steel building has no beams and no purlins, wide space, large spanning capacity, and the span of 6-32 meters can be chosen at will. Low cost, low investment, economical. The design and construction period is short,
The roof construction of Agricultural steel building can be completed in 20 days. Colored galvanized steel sheet, mechanical seam connection, natural waterproof, no leakage.
The Agricultural steel building is beautiful in appearance, sturdy and durable, and requires no maintenance.
The Agricultural steel building is light in weight, the overall structure is scientific and reasonable, and the wind and seismic performance is superior. Wind resistance and snow load, can withstand strong winds of 160km/n per hour, and can withstand a snow load of 148kg.
The shape of Agricultural steel building is beautiful, colorful, novel and full of rhythm. Rich and diverse roof forms give the building a new appearance.
The Agricultural steel building has complete functions, the roof slab and beam are integrated, and it integrates multiple functions such as heat preservation, heat insulation, ventilation, and lighting.
1 Personnel engaged in high-altitude operations must hold a certificate to work, and earnestly abide by the safety construction regulations, wear flexible clothing, and it is forbidden to wear hard-soled and slippery shoes with nails;
2 Workers of Agricultural steel building wear safety belts;
3 A safety net is set under the working surface of Agricultural steel building;
4 Materials for high-altitude operations should be stacked steadily. They should not be placed on the edge or attached to the opening of the hole. If there is a possibility of falling, they should be withdrawn or fixed in time to prevent falling objects from injuring people.
The Agricultural steel buildings made by Qingdao Xinguangzheng Steel Structure Co., Ltd. feature attractive appearance, excellent performance, easy maintenance, and internationally advanced performance indicators, and are exported to more than 10 countries and regions.
Generally speaking, Steel building accessories include: steel column systems, steel beam systems, support systems, connection systems, purlin systems, and brace stairs. This is a part and an indispensable part of every steel structure project.
What are the advantages of using Steel building accessories?
How to paint Steel building accessories?
What may cause the deformation of Steel building accessories?
In the process of using Steel building accessories, dry construction is used to reduce the environmental pollution caused by waste. The Steel building accessories of the house can be 100% recycled, and most of other supporting materials can also be recycled, which is in line with the current awareness of environmental protection; All materials are green building materials, which meet the requirements of ecological environment and are conducive to health.
The wall is built by Steel building accessories, and the high-efficiency energy-saving system is adopted, which has breathing function and can adjust the dry humidity of indoor air; The roof has ventilation function, which can form a flowing air room over the house to ensure the ventilation and heat dissipation requirements inside the roof.
All dry operations shall be carried out without being affected by environmental seasons. A building of about 300 square meters only needs 5 workers and 30 working days to complete the whole process from foundation to decoration.
4. Environmental protection
Materials can be 100% recycled, truly green and pollution-free.
5. Energy saving
All adopt high-efficiency and energy-saving walls, with good thermal insulation, heat insulation and sound insulation effects, which can reach the energy-saving standard of 50%.
(1) Method of painting construction:
There are two commonly used methods in Steel building accessories maintenance engineering, namely, painting method and spraying method.
(2) Matters needing attention:
1) The base layer should be thoroughly cleaned before painting, and kept dry, and the first coat of primer should be applied as soon as possible within no more than 8h.
2) When applying the primer, choose an appropriate painting method according to the size of the area.
3) When painting the top coat, it should be painted according to the color and variety requirements of the design, and the painting method is the same as the primer painting method.
4) Painting environment
5) The thinner should be used correctly.
(1) The actual dynamic load of Steel building accessories exceeds the maximum load (commonly known as "overload") allowed during the design of the steel structure.
(2) Bearing the impact of dynamic load for a long time.
(3) The impact of natural disasters (such as earthquakes) or uneven settlement of foundations.
(4) Improper use and maintenance or breakage of Steel building accessories due to mechanical damage and withdrawal from work, resulting in an abnormal deformation of the steel structure due to unbalanced forces.
Qingdao Xinguangzheng Steel Structure Co., Ltd. is known for high precision Steel building accessories. And you can connect them.
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.