鋼結構工程施工方案[中文9082字] 【中英文WORD】
鋼結構工程施工方案[中文9082字] 【中英文WORD】,中文9082字,中英文WORD,鋼結構工程施工方案[中文9082字],【中英文WORD】,鋼結構工程,施工,方案,中文,9082,中英文,WORD
Steel Structure Construction Scheme
Ⅰ.A brief account of steel structure work
There will be 6 8t bridge traveling cranes in production hall, welding H-section steel column and beam, structural main material is Q345B, cold bending sheet steel Z-purlin, wall and roof cladding are double-skin pressed steel sheet and thermal insulation wool.
Ⅱ.Characteristic of steel structure work
The single span of the work is 18m, the height of steel column is large, single frame plane external rigidity is very small, so the key point of safety technical control is to guarantee the stability outside the structural plane.
Take out 6 steel columns from grid line 9~14 in the production building, instead of 52.5m space truss as trimmer beam to support the upper structure and crane load, the installation of the space truss is a difficulty point of this work.
Ⅲ.Fabrication of steel structural members
Technical preparations prior fabrication
1. Study and check the design working drawing before fabrication, make shop drawing and get approval from designer then prepare material for fabrication.
2. Make a plan and program for fabrication as per the type, quantity and material of the structural members.
3. Write construction techniques and technical measures, and the equipment regular examine and maintain plan, keep the machinery in good condition.
Material requirements:
1. Select and confirm the material for the project.
2. All kinds of material should be with quality guarantee and ex-factory certificate. If there is any doubt, sampling examination should be taken according to relevant national standard, only when passed the examination material in batches can be used.
3. Rust degree of steel surface should conform to the present national standard .
4. Jointing material (welding rod, solder, flux), high strength bolt, and coating( under coat and top coating) should be with ex-factory quality certificate and conform to the design and national standard.
5. If the skin of welding rod is peeled off or the core is rust, welding flux is wetting and agglomerating or melting, the high strength bolt is rust/damaged or taken from different batches, these materials are strictly prohibited.
6. Anti-corrosion paint should conform to the design and relevant standard, and with quality certificate and operation instruction.
Equipment and tool preparation
1. Check and maintain the fabricating equipment in advance.
2. The fabricating tools and measuring instrument should be with certain accuracy, and be examined and marked by the measurement testing department regularly.
3. Welder should bearing the qualification certificate, and do the work within the scope stipulated in certificate. If the welding work stopped more than 6 months, the welder should be re-examined and passed the examination.
Key points of steel structural member fabrication
welding
adjustment
part assembly
Integral assembly
End milling
welding
adjustment
End milling
Puching
Rust-removal
Annealing tr
Painting & packing
Semi-ready product storage
bending
Edge machining
Punching and boring
Second material utting 割
Ex-factory
lofting
Raw material calibration
Cutting,punching,sawingsawing
Gas cutting
Spare parts straightening
assembly
welding
adjustment
Ⅳ. Steel structure installation method
Preparations prior to installation
As per the requirement of steel structure installation, before installation work started, it is need to check and clear the site, insure the access for hoisting is smooth and firm, and construction power is ready, the following works are also need to do simultaneously:
1. Survey the horizontal level and axial deviation of the all groups of embedded bolts, make records for the handing over with the civil work team in writing.
2. The since the quantity of structural members is large and has a great variety, it must be numbered and confirmed to avoid mis-placed.
3. Make necessary inspection and acceptance jointly with the employer and supervisor before installation.
Transportation and storage of structural members
1. Transport structural members by appropriate vehicle as per the geometric dimension and unit weight, make necessary soft mat and binding during transportation.
2. While loading/unloading and moving the structural members, it must be handled gently. Insert spacer while necessary to avoid damage the painting.
3. Someone must be put in charge of transportation and storage.
Structure hosting and installation method
1. Consideration about installation of steel structure
The type the structure in this project is a standard portal-framed structure with moving crane beam, external rigidity of a single frame is small, the sequence of mobilization of structure is start from grid line 1, first install steel frame at grid line 1~2, bracing to column and roof installed and adjusted simultaneously to form a stable space system, then moved to grid line 29. Steel column to be hoisted and installed through Singe-Crane-Rotating-method, the steel beam to be hoisted through Two-Crane-Lifting-method after assembled on the ground. Truss trimmer to be assembled with bolts on the ground and hoisted through Two-Crane-Lifting-method. Space between crane beam and roof purlin is 3.5m, it is enough for minimum hosting space, and can be done after the structure installed or alternated in.
2. Hoisting and installation and adjustment of steel column
Steel column to be hoisted through Rotating Method.
Someone must be in charge of hoisting and installation, safety, quality and technology to be talked over in details before hoisting.
For the efficient hosting, while piling the columns, put the binding point/column footing center/base center at a same arc.
While the column is being hoisted slowly 20cm above the floor, stop hoisting for a while to check the sling and crane, open the swing brake, then put the column down at 40~100 mm to the installation plane, align to the datum line, direct the crane descend, insert the column to the anchor bolt and fixed temporarily, tie the column at two direction to stable the column structure.
After initial adjustment of the column, only when the vertical deviation controlled within 20mm then can remove the hook of crane, check the verticality with theodlite, any deviation to be adjusted immediately, while adjustment is being done, observe the bottom and level control block to avoid horizontal level deviation.
Vertical adjustment of the column, fix two theodlites to the longitudinal and transverse axis, first aim at the column bottom wing or center line then move upward to the column top, if the center line drifted off the line of sight, to adjust the tie rope or support, make the column to be vertical through prying. Usually to erect a row of columns first then to do adjustment. At that time, two theodlites can be placed at one side of longitudinal and transverse axis, deviation to the centerline not more than 3m. while hoisting roof truss or installing vertical members, the steel column must be re-check and adjusted.
2. Hoisting and installation of steel beam
3. After the steel beam turned over and positioned, trial hoist must be done repeatedly and bond again , while trial hoist is being carried out it must be lifted slowly, the best state is that uniform force at each point and the beam will not deformed, then to hoist and rotate to the designed position, pull the controlling rope buckled on the beam in advance by hand on the ground, rotating to the position, fix the column and beam connecting hole with high strength bolt. Since the first hoisted beam length is 46m, 5 guy ropes should be tied, while fixing it, check the verticality with pendant. The second and the after beams to be fixed temporarily by the roof purlin and tie beam..
4. Re-check the column while hoisting the beam, normally use the chain block and steel wire rope, the rope to be removed till the beam installed. The steel beam ridge line must be controlled. Make the deviation between the truss and the column ends center line be equal, so that all the roof truss to be at a same center line.
The connection of the high density bolt
Material
1. The bolt, nut and washers will be accompanied with the quality pass certificate of which is complied with the national standard and the specification.
2. The bolt, nut and washers should be in uniform. The thread should not be worn-out. It should be in clean and dry state and be kept in the storage according to the specification.
Preparation to the bolt before installation
1. Check each part of the installation is in right position and make sure that the installation is comply with the “Regulation for check and acceptance to the quality of steel structure work” code no. GB50205-2001
2. Check the main material with the hole is correct in diameter and the size. Make sure that the smooth is met the specified requirement. If there is thread on the main material, we immediately remove it.
3. We shall familiar with the installation construction drawing and program schedule and make full preparation to the work spanner and the other related equipment.
4. Preparation to the measuring tools
The workmanship
1. The connection to the steel plate must be straight, the side and hole should contain no thorn to make sure the surface is closely attached. If there is the bending, we shall make necessary adjustment and avoid the damage to the fraction surface.
2. Before fixing, we shall clean dirty oil and paint on the hole side.
3. Before installation, we shall use temporary bolt to fix in position, the number will be more than one third of the total number for the connected bolt. The method is pre adjust the steel hole and put the temporary bolt inside and then use the nut to screw it. There will be two temporary bolts in each point. Not allowed to use the high density bolt to be served as the temporary bolt. After one section is completed, then to check it and confirmed then to carry out the work with the high density bolt.
4. While install the high density bolt, we shall make sure that the central position is check and no mistake and then procedure the work of the high density bolt (This project adopt the double nut screw tight). The washer will be put on one side of the nut and be sure not in opposite direction. If the bolt cannot be through the hole freely, we shall use the knife to adjust the hole and then procedure the work. It should not use the force to go through the hole so as to avoid the damage to the thread. Clean the thorn after adjusting the hole.
5. The tight for high density bolt: This work will be in two stage, the first stage is called preliminary tight, the tight force is about 50%-60% of the designed pre-pull force. The second stage is called the final tight. The tight force will reach the designed pull force. The deviation will be less than ±10%. The pre-pull force will be determined according to the designed specification. During the work, the spanner force formula will be Tc=k*Pc*d k=0.11~0.15 Pc(designed pre-pull force) d=the diameter of the bolt.
6. Check the turn space spanner mark record and the bolt construction record. If there is any questioning, we shall check the preliminary tight record.
Quality standard
1. The high density bolt’s type, specification and the technical condition should be comply with the designed specification and the related standard. We must carry out the test to determine the turn space coefficient and recheck bolt pre-pull force and check the quality pass certificate and the test report.
2. The connection surface for the bolt in friction coefficient will be complied with the designed requirement and the related specification. On its surface, there should be no rust, thorn, welding remaining, dirty oil and paint, etc.
3. The high density bolt must be tight in two stage, the quality of the preliminary and final tight should be complied with the construction regulation and the related specification.
4. The high density bolt will be put through in the same direction and the thread rings should less than 2 rings.
5. The friction surface between shall complied with the designer and the regulation for steel structure check and acceptance requirement.
Items to be taken in consideration during the installation for high density bolt
Quality control
1. The surface with rust, dirty oil, thorn and welding remaining should be cleaned.
2. After treating the friction surface should be reached the anti slide coefficient requirement. The use of the high density bolt and the nut, washers should be uniform and be used at the same time not allowed to exchange.
3. Treat the part’s friction surface. While installation, there will be no dirty oil and soil, etc
4. While installation the part, the friction surface should keep dry and avoid to work in rain.
5. Before installation, we shall check and recheck the connected steel plate and make necessary adjustment to the bending.
6. While installation, we shall not use the hammer to hit the bolt to avoid the thorn of the bolt be damaged.
7. We shall check and measure the spanner timely to the preliminary and the final tight of the high density bolt. We shall make sure the precise and do the necessary record. The tight work will be carried on in right procedure.
Major safety technical measures
1. To use the flexible spanner the size will fit the nut. While work high above the ground, we shall use the fixed spanner. If we are using the flexible spanner, we shall be tied with safety belt.
2. While assemble the steel part to connect the bolt, we shall avoid to use the hand in testing the screw hole. The hand will be on the side of the steel plate.
Ⅴ.The roof panel installation method
The installation of the color steel sheet composed of the detailed part design, production sequence, transport and installation, etc. Every part of the work and the method is the key link to the project’s completion, safety, and quality. The installation work will be carried out after the steel structure work has been completed with the formality of the check and accept certificate.
Detailed part design work
This part of the detailed design plays a key role to the installation. We shall magnify every connection point on the original drawing so as to instruct the work and workmanship procedure. The followings are the main content for the detailed design:
1. The roof coverage arrangement
2. The connect point enlarge drawing (include the treatment to gutter, the joint, facial and flush)
3. Detailed part design flow
Project →construction joint design→edit drawing→check→audit→sent→issue
Preparation for the color steel sheet installation
1. Before the installation of the color steel sheet, we shall check the size between the structure parts, the level and the quality. If there is any bending on steel structure parts, we shall carry out the adjustment work immediately.
2. Before the installation of the color steel sheet, we shall check those already installed cool bend thin plate part of which should not be heavy loaded or welded.
3. Before the installation of the color steel sheet, we shall make sure that the pull pole or the press pole are tight and the purlin are in right position. The twisted angle for prulin should less than 3°.
4. Before the installation of color steel sheet, we shall check all the cool bended structure whether the parts are treated with the rust protected, fire protected, convenient for inspection, brush, paint, avoid water collected and sealed the end of the steel structure part.
5. The temporary stack for color steel sheet should be arranged according to the general construction layout to put in position. We shall prepare a solid compacted, flat area with good drainage system and convenient transportation for color steel sheet and temperature reserve cotton. We shall also make sure that the area will have the measures to be covered with plastic clothe to protect the rain water.
6. We shall make sure that the installation tools, equipment, protect items, connect parts, prop and the accessories to the color steel sheet are fully prepared. All these will be tested and qualified. These items will be in storage with a full time person to look after.
7. We shall make sure that the staff will be fully understand the technical, quality, safety of the work before undertaking the roof installation work. We shall make them fully understand the construction drawings, work method, safety operation, quality requirement. We shall recheck the axis for the installation parts, the level, etc.
The installation method of Color plate
1. The installation of roof panel started from the gable. Survey and set a datum positioning line at the lower end of roof in advance to guarantee the accuracy of installation, then install in order.
2. Check the roof panel in lengths (normally ten panels) during installation, to check the straightness of the two end of the panel and the parallelism to avoid that it will be inclined or fan-shaped. Necessary adjustment to be done during installation, micro-adjustment to be done one by one to meet the requirement of quality.
3. Joint of roof panel in length direction will be over-lapped on the bracing members, lapping length is 250mm.
4. Reliable sealant to be done to lap at the length direction of the roof panel, silicone or weather strip to be filled at two ends, 15mm apart from the panel end. Bottom panel over-lapping length is 80~100mm, sealant might not be done at over-lap.
5. Leave 50mm gap between two panels at ridge, it is preferable to bent the panel upward at 80” to form a flashing. The pressed steel panel to be projected 120mm at gutter, bent downward at 10” to form a drip.
6. Over-lap of flashing board not less than 100mm, with enough width and rolled edge, spacing of joints not more than 50mm. Sealant to be done to over-lap for water-tightness.
7. At roof ridge and interface between upper and lower span, flashing and roof panel to be jointed by over-lap, lap not less 200mm, insert waterproof closure in lap.
Ⅵ. Wall panel installation
1. Wall panel to be installed prior to roof eaves gutter with special purpose hoisting and clamping apparatus.
2. The first wall panel to be installed as per the gable outside corner line, use theodlite and or pendant to fix the datum line.
3. Screw to be fixed to the top and bottom end of the wall panel for temporary positioning, when a group (about 10) of panels laid and adjusted, fasten the screw to the wall purlin.
4. Mark the position of screw between wall panel and purlin, it should be even to the purlin and be uniformly arranged.
5. Install the panel to be over-lapped in length direct from bottom to top, the over-lap to be arranged at the position wall purlin, inter panel over-lapping length is 80－100mm, outer panel over-lapping length is 120mm, sealant might not be needed at over-lap.
6. Inspection to be done by rooms for wall panel, use theodlite or hang the pendant at column center line to survey the verticality.
7. Gable panels to be cut at different length as per the roof pitch, then to install it. Add end closure to gable eave flashing if necessary.
8. Gable flashing to be done started from eave up to the ridge after the roof and wall panel installed. Outside corner panel to be down from bottom to top, rivet to be used for the joints to wall panel, spacing as per the technical requirement.
9. Door and window flashing started from top to the two sides, use wall purlin or door/window frame for fixing. If it is to be connected to the pressed plate, use rivet for joint. Flashing at opening on wall, it’s top to be installed inside the wall panel, bottom outside the wall panel. To fix the wall panel and flashing to the wall purlin with self-tapping screw.
10. Joints between flashings to be s
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