Plant steel structure hanging construction quality control knowledge

The construction quality control knowledge of the steel structure of the plant
The steel roof stand should check the straightness of the vertical string rod. The verticality of the roof can be tested with a vertical ball, and the flatness of the string can be tested with a tightened rope. The following is the knowledge of the construction quality control of the steel structure of the factory of the factory of the factory. Welcome to read and browse.

The preparation of preparation before hanging
1. Preparation of construction organization design
The main contents of the construction organization design include:
Select the lifting machine; determine the flowing program; determine the lifting method; formulate the progress plan; determine the labor organization; plan the steel component yard; determine quality standards, safety measures and special construction technology.
The choice of lifting machinery is the key to the installation of steel structure. The model and quantity of the lifting machinery must meet the lifting requirements and construction period requirements of the steel component; the area of ​​the single -layer industrial plant is large, and it is advisable to adopt a self -proclaimed lifting machinery. For heavy steel structure factories, CC2000-30T crane cranes can be selected and Ⅱ-Ⅱ1495-100T crane cranes.
Is when determining the lifting flowing program, first determine the work content of each lifting machinery and the mutual cooperation between the lifting machinery. The depth of its content must be reflected in a single part of the key component, the vertical component reflects the column, and the roof part is reflected in the interview. For heavy steel structure plants, the pillar weight is large, and it must be lifted in sections.
In determining the order of the lifting order, consider the installation component convenient and meet the order of production equipment.
1.2, preparation of the foundation of the steel column n The top surface of the steel column foundation is usually designed as a plane, and the steel column is connected to the basis through the ground foot bolts. Pay attention to ensure the accuracy of the base elevation and the position of the ground foot bolts. The deviation of the foundation support surface, support and ground bolts of the steel structure shall comply with relevant regulations.
In order to ensure the accurate position of the ground bolt, steel can be used as a fixed frame during construction, and the ground foot bolts can be placed on the fixed rack separated by the basic template, and then the concrete is poured. To ensure that the ground foot bolt is not damaged, you should apply butter and put it with a plastic sleeve.
In order to ensure the design requirements of the basic top surface, according to the form and construction conditions of the pillar, the following two methods can be used:
1.2.1 One -time pouring method
Pour to the design elevation at a time. In order to ensure the accuracy of the high elevation of the support surface, first pouring the concrete to about 20-30mm lower than the design elevation than the design elevation, and then the corner steel or groove steel guide rack at the design elevation, and then the elevation of its elevation. To the design elevation. The first pouring method can be used to avoid the second pouring work of the pillar.
1.2.2 Two -time pouring method
The pillar foot supporting concrete is divided into two times to the design elevation. For the first time, the concrete was poured to about 40-60mm lower than the design elevation. After the concrete reaches a certain intensity, place the steel pads and accurately calibrate the elevation of the steel pads, and then hang the steel column. When the steel column is corrected, pour the fine stone concrete under the pillar soles of the pillar. Although the second pouring method has an additional process, the steel column is easy to correct, so the heavy steel column is mostly used.
1.3. The inspection of the component and the bomb line
The shape and geometric size of the steel component can ensure that the structure installation is smooth. To this end, before the hanging, the shape and geometric size of the steel component should be carefully tested in accordance with the relevant provisions in the "Steel Structure Engineering Construction and Acceptance Standards". In addition, in order to facilitate corrected plane positions and verticality, high benchmarks of truss and crane beams, the axis of two directions is marked at the bottom and upper part of the steel column. Lalate the position of the tied point.
The components that are not easy to distinguish between up and down, left and right, should also be indicated in the component to avoid making mistakes when hanging.
.4. The stability of the decoration of the truss
When the truss is lifted, the minimum specification of the trussed and lower -string corner steel should meet the relevant regulations. Guarantee stability. If the specifications of string rod corner steel do not meet the relevant regulations, but by calculating the position of the proper hanging point (bundle point) position, it is still possible to ensure the stability of the trusses. Specific methods can refer to relevant literature.
2. Selection of the steel structure lifting machine
The choice of crane machine is an important problem of hanging project, because it is related to component installation methods, lifting machinery routes and shutdown positions, component plane layout and other problems.
2. 1. The type of crane type
The crane types for the installation of the structure are mainly determined based on the factory span, component weight, installation height, construction site conditions, and local existing lifting equipment. Generally, the structure of small and medium -sized factories is more reasonable. When the height and span of the plant structure are large, the tower -type crane can be used to install the lid structure. Where there is a lack of self -proclaimed cranes, mast cranes can be installed. Large -span heavy industrial plants often need to consider the installation of structural components in combination with equipment installation. The selected cranes must be installed not only the load structure of the plant and the installation of the equipment. , Large -scale cable -type mast cranes. For heavy components, when a crane cannot be lifted, two cranes can also be lifted.
2.2. After the length of the crane model and the length of the lifting arm
After the type of the crane is determined, the model of the crane and the length of the lifting arm need to be further selected. Three working parameters of the selected heavy machine: the requirements for the weight, the height of the lifting, and the lifting radius should meet the requirements of the structural hanging.
2. 3. The number of cranes. Determine the number of crane required for the required crane, according to the quantity, construction period, and crane output output quota. In addition, when the number of cranes is decided, the workload of component loading, unloading, assembly and emissions should be considered.
3. The craftsmanship of the steel structure component
The steel structure component of the factory, including columns, crane beams, roof frames, sky window frames, bars, support and wall frames, etc. They are different. Different lifting machinery and lifting methods should be adopted to achieve economical reasonable.
Part 2: Methods and precautions during the lifting process
3.1, the lifting of steel columns
3.1.1, the rising of the steel column n Steel columns are usually lifted with self -propelled cranes or tower cranes. The crane method of the steel column is similar to the prefabricated steel concrete column, and it is also a rotating hanging method and a sliding lifting method. Double -machine lifting can be lifted with a double -machine lifting. When hanging up, the dual machine hangs up the steel column at the same time, and then suspend it after a certain height from the ground. The flat car that transports the steel pillar is moved. Then the dual machine can also improve the rotary brakes at the same time. The tied steel wire rope under the auxiliary machine will insert the steel column separately into the anchor bolt by the host. The verticality of the first school, the deviation is controlled within 20mm before it can be loosened.
3.1.2, the correction of the steel column is tested by the latitude and weft meter with fixing
The deviation of the verticality of the steel column. In the process of correction, observe whether the bottom of the pillar and the elevation control block at any time are available to prevent the error caused by the horizontal elevation during the correction process.
The correction of the position of the steel column. For heavy steel columns, you can use a spiral jack and a chain cover to hold the seat, and the steel column is topped along the horizontal direction. This method is first adopted in Shanghai Baosteel's construction. The effect is ideal. The displacement accuracy after correction is within 1mm.
It to prevent displacement of steel columns after correction, use 10mm thick steel plates on the four sides of the column, and fix it with electric welding. After the steel column is resumed, the anchor bolt is fixed, and the upper and lower dots of the load -bearing block are fixed to prevent walking around
3.2. The hanging of the crane beam
After the steel column is lifted, the crane beam can be lifted. The crane beams in the industrial plant are divided into three types: light, medium and heavy according to the lifting capacity of the lifting equipment. The light weight is only a few tons, the heavy span is greater than 30m, and the weight can reach more than 1000kn.
The steel crane beams are all in the form of simplicity, and there is a gap of about 10mm between the two ends. There is a gap between the beams and the beef legs and a steel plate. Liang and beef legs are connected with bolts, and high -strength bolts between beams and brake racks are connected.
3.2.1. Precautions before hanging
Pungeon the deviation of the displacement and verticality after the steel column is lifted; Control the axis.
3.2.2. The lifting of the steel crane beam
The crane beam is commonly used by the crane beam, which is used mostly with a crawler crane. Tower cranes, rods, mast cranes, etc. can also be used for lifting. For cranes with a large weight, a double -machine lifting can be used. For those with huge huge people, temporary brackets can be set for hanging segments.
3.3.3, the correction of the steel crane beam and the fixed
The correction of the crane beam is mainly the correction of the elevation, verticality, axis, and span. The correction of the elevation can be carried out before the lid is lifted. The correction of other projects should be carried out after the ceiling is lifted, because the lifting of the lid may cause the steel column to change position.
The method of testing the axis of the crane beam is the same as the reinforced concrete crane beam. It can be used to use the wire method or the translation axis method.
The test of the crane beam span, measured with a steel ruler, and a large span workshop for a spring scales (generally 100-200N) to prevent the steel ruler from sagging.
The crane beam label correction is mainly to move the beam vertically. You can use a jack or a crane. The axis and span are the movement of the horizontal direction of the beam. You can use a sled, steel wedge, flower basket screw, jack top, etc.
In the correction of the crane beam, fix the connection bolt, and fix the steel pads with electric welding.
3.3, the lifting and correction of the steel roof frame
The steel roof frame can be lifted with a heavy machine (especially a crawler crane), a tower crane and a mast crane. Due to the different span, weight and installation height of the roof frame, different lifting machinery and hanging methods should be selected. The side stiffness of the steel roof stand is poor. If you roll over and lift up, you should be tied for a few fir rods if necessary as a temporary reinforcement measure. Most of the roofs are suspended. In order to make the roofs swing after hanging up and collide with other components, the skating rope should be tied at both ends of the roof before the hanging, and the suspension is relaxed to maintain its correct position. Temporary bolts and punching of the roof are temporarily fixed.
The sideline stability of the steel roof stand is poor. If the lifting weight of the lifting machinery and the length of the lifting arm is allowed, it is best to use the expansion and assembly. The sky window frame, tape bar, support, etc. are assembled as a whole, and it is lifted at a time, which not only improves the hanging efficiency, but also helps to ensure the stability of the lifting.
The steel roof frame should check the flatness of the vertical string rod. The verticality of the roof can be tested with a vertical ball, and the flatness of the string can be tested with a tightened rope.
The final fixation of the steel roof frame, welding or high -strength bolt.
4. The steel structure connection is fixed with
The steel structure connection usually has welding, riveting and bolt connection. The bolts are connected to ordinary bolts and high -strength bolts. The high -strength bolt also has a large hexagonal head high -strength bolt and twist -cut high -strength bolt. Twist -cut high -strength bolts have simple construction, good force, disassembly replacement, fatigue resistance, can withstand power loads, can visually determine whether it is finally twisted, not easy to leak, high safety, etc.
4.1, high-strength bolt connection sub- n according to national standard GB3633-83, the steel structure is connected to a twist-cut bolt, including a bolt, a nut and a pad.
The high -strength bolt is generally made of 20mntib steel, the nut is made of 15mnvb or No. 35 steel, and 45 steel is made of 45 steel.
4.2, construction process
4.2.1, friction surface treatment
high -strength bolt connection must be processed on the component friction surface. For the manufacturer, sandblasting, spraying (throwing) pills, pickling or sand wheels can be used in the manufacturer. There should be protection measures for handling friction surfaces and shall not be painted or dirty. The manufacturer's treatment of the friction surface should be re -checking the friction coefficients in a group before installation.
4.2.2, connecting board installation
The connection board cannot be deformed, otherwise it should be used after correction.
The high -strength bolt plate surface contact should be flat, and the gap between the connecting surfaces is caused by the thickness of the connected components, or the production and installation deviation. No treatment; d = 1.0-3.0mm, grind the thick plate into a slow slope of 1:10, so that the gap is less than 1.0mm; d> 3.0mm, and the pads should be added. Essence
4.2.3, high -strength bolt connection
The installation requirements
The form and specifications of the high -strength bolt selected should meet the design requirements. When the length of the bolt should be selected, the thickness of the connection, the thickness of the nut, the thickness of the thread, the thickness of the cushion, and the tightening of the component should be exposed.
It high -strength bolts In the process of transportation, storage and use, it is necessary to prevent rust, staining, and bumping threads that may cause changes in torque coefficients. The high -strength bolt connection (that is, the high -strength bolt with a supporting nut and pad), should be used in the same packaging box. When there is a surplus of construction, it must be stored separately according to the batch number, and it must be mixed.
The high -strength bolt connection surface friction coefficient test results meet the design requirements. The surface of the component can not be painted on the surface of the surface, no oil pollution, iron oxide skin (black skin), burrs, and flying edges. There is no obvious unevenness and warning. Clear rust and dust with fine steel wires before assembly.
In installation method:
The high -strength bolt joints are used to connect to the nail and temporary bolts. The number of temporary bolts is 1/3 of the total number of bolts on the joints, and it is not less than two. The number of dumps should not exceed 30%of the number of temporary bolts.
This must not cause the snail hole to deformation due to forcibly hitting.
The high -strength bolts instead of temporary bolts are strictly prohibited to prevent torque coefficients increase due to damage threads.
The misplaced bolt holes can be treated regularly with re -cutter or coarse knife. When processing, the temporary bolt should be tightly tightened to the section without gaps to prevent crumbs from falling into. It is strictly forbidden to use flame cutting to sort out the holes.
The structure should be corrected in installing accuracy in the temporary bolt connection state.
The structure installation accuracy adjustment can be installed after reaching the standard regulations. First of all, if you install the split holes that are not installed in the joints and the nails, the bolt should be freely penetrated into the threaded hole (the bolts must not be cut), and the direction of the penetration should be consistent.
It the high -strength bolt of these installed ones with ordinary wounds, and then use the high -strength bolts to flush nails and ordinary bolts with a high -strength bolt ring one by one.
The operation process of the entire installation of high -strength bolts should be maintained in a dry state and a bolt connection. If there are too many lubricants or rust -proof agents on the surface of the connected sideline, you should use a clean and firm cloth, gently wipe off the excess fat to prevent it from flowing to the connector, and avoid using a cleaning agent to use a cleaning agent. Clean to avoid changes in torque coefficient.
4.2.4, the tightness of the high -strength bolt
is to make the pre -tensile power of each bolt uniformly, and the tightness of the high -strength bolt is performed at least twice. The first time is the initial, the second is the final twist. For large -scale high -strength bolt joints, it is also divided into initial twist, repeat, and final twist if necessary.
The initial twisting, repeat, and final twist of high -strength bolts were completed within the same day. The bolt is tightened in a certain order, and it should generally be tightened outward in the central order of the bolt group.
4.2.5, the construction quality inspection and acceptance of the high -strength bolts connected to the sideline
This -cutting high -strength bolt final twisted inspection. When tightening with a dedicated wrench, it is qualified with the tail plum head. For high -strength bolts that cannot be tightened with a dedicated wrench, check the high -strength bolt check method of the large hexagonal head.
Ifly if there is no compliance, it should be expanded by 10%. If there are still unqualified those, the high -strength bolts of the entire node should be tightened again. The torque check should be completed after the final twisting 1h and before 24 hours.
The tightening of high -strength bolts at high altitude, we must follow the safety precautions of the heights. The tail of the high -strength bolt that is twisted should be put in the toolbag at any time, and it is strictly forbidden to throw it away.
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