Installation technology of steel roof truss

1 scope

This technology is applicable to General section steel roof truss installation works.

2 construction preparation

2.1 materials, semi-finished products and equipment:

2.1.1 steel components: models, making the quality of steel Member should comply with the design requirements and provisions of the code, should have a factory certificate and shall be accompanied by a technical file.

2.1.2 connection material connection materials have quality certificates such as welding rods, bolts, and to comply with the design requirements and the relevant provisions of the national standard.

2.1.3 coating: anti-rust performance shall conform to the design requirements and the provisions of the relevant standards, certificates of product quality.

2.1.4 other materials: variety of horns, and so on.

2.1.5 major equipment: lifting machinery, lifting and rigging, welding, Electrode holder, welding wire, wood, Horn, wrenches, pry, Torque Wrenches, hand wheel, electric drills, and so on.

2.2 operating conditions:

2.2.1 the component list, check the entering the number of artifacts, inspection of factory certification and related technical information.

2.2.2 checking components in loading and unloading, transporting and stacking damage or deformation. Damage and deformation of the components should be corrected or reworked. Anti-rust coating of touch-loss, and once again check the acceptance formalities.

2.2.3 components of profile geometrical dimensions, drilling, Assembly, welding, friction surface checks, making records.

2.2.4 component should be the order of installation of steel structure supply, field pile site to meet the needs of field assembled and installed in the order. Roof fragment factory, groups together at the scene should be prepared to assemble the Workbench.

2.2.5 component classification stacked, stacked component can pave the way wood stiffness levels. When several stacked on a vertical wood. Roof trusses should be standing, next to the post, binding firm.

2.2.6 preparation of construction organization design of steel structure installation, approval, and team cards.

2.2.7 checking for installed base and embedded parts, total package made qualified acceptance of information.

3 operational processes

3.1 process:

Job preparation spell → group → roof truss roof truss installation connected with fixed → → → rust inspection, acceptance, brush coating

3.2 installation preparation:

3.2.1 to reinspect the installation position the axis of the control points and measuring elevation benchmarks.

3.2.2 release level control line and axis of the roof truss installation guides.

3.2.3 to reinspect the embedded parts of the roof supports and supporting systems, its axis, height, level, location and length of exposed embedded bolts, etc, when tolerances are exceeded, should complete the treatment.

3.2.4 checking hoisting machinery and hoisting, in accordance with the requirements of construction organization design of erection of scaffolding or platforms.

3.2.5 truss Web design for rod, but when lifting due to the hang point location so that it forces change-lever, to prevent deformation, instability, reinforced measures should be taken, if necessary, in the direction parallel to the roof top, bottom with steel, wood, or other provisional measures.

3.2.6 measurement ruler and ruler for making proof of steel structure and legal units of measurement achieved approval and certification.

3.3 frame groups together:

Roof fragment brought on to the site to assemble, Assembly platforms should be flat. When groups fight should ensure that the total length of the roof truss and Arch sizes you want. Welding welding end side after passing the examination, and then rolled over welded side, good construction records. Check rear allow installation. Roof trusses, and skylights can also be assembled on the ground lifting, but temporary reinforcement to ensure lifting had sufficient stiffness when.

3.4 roof truss installation:

3.4.1 lifting point must be located in the roof trusses on three concurrent node. Roof lifting off the ground 50cm pause, check and correct to continue lifting.

3.4.2 when you install the first frame roof, release the hook before the initial correction; align roof trusses centerline or axis positioning of supports in place, adjust frame vertical and check the roof direction bending, roof temporary fix.

3.4.3 second pin frame the same way when the hoisting, don't loose hooks, use Cedar pole or beam to temporarily fixed with the first frame roof trusses, support system and part of the Purlin, finally correcting fixed, so the first pin roof trusses and the second frame roof truss to form a spatial stiffness and stability as a whole.

3.4.4 starting from the third frame roof, installed in the roof and the midpoint of the chord Purlin roof can be fixed on, while room correction well.

3.5 Member connections and fixed:

3.5.1 components are installed with welded or bolted joints, check the connections, qualified before welding or tightening.

3.5.2 installation bolt holes are not allowed to use gas cutting, reaming pad more permanent bolts washers, exposed threaded length not less than 2~3 buckles.

3.5.3 install tack when you do not need to load, weld design weld thickness of not less than 2/3 and less than 8mm, weld length should not be less than 25mm, the location should be within the weld. Installed full Visual inspection of weld, mainly according to the design requirements of ultrasonic inspection of weld quality. These checks are required to make a record.

3.5.4 welding and high-strength bolting process as described in the standard.

3.5.5 roof bearing, support structure of the system should be checked carefully, you must comply with the design requirements and spare parts may not be missing.

3.6 check acceptance:

3.6.1 roof quality connection first check after installation.

3.6.2 roof truss installation Center for quality check roof for two supports vertical no vertical; compression chord trusses of roof trusses on sides of the vertical surface, must ensure that the deviation does not exceed the tolerances mentioned above, to ensure that the roof with the design stress and stability requirements.

3.6.3 roof elevation, axial displacement of the bearing, mid-span deflection, measured a record.

3.7 removing rust, paint:

3.7.1 connection weld without welding slag, oils, derusting qualified before brushing paint.

3.7.2 dry paint film thickness of coating should comply with the design requirements or provisions of the code.

4 quality criteria

4.1 project:

4.1.1 installation engineering quality inspection and evaluation of steel structure, should be in the welding or bolting after the quality inspection and assessment of compliance with standards.

4.1.2 components must meet the requirements of specification for design and construction, factory certificate check components and accessories. Deformation due to transport, stacking and lifting must be corrected.

4.1.3 support position, done right, contact surface smooth and firm.

4.2 Basic project:

4.2.1 members tag; centerline and elevation benchmarks complete clear.

4.2.2 structural surfaces clean, welding scar-free, oil-sand and mud.

4.3 allowable deviation; see table 5-13.

Table 5-13

Project tolerance (mm) method

1 straight l/1000 truss chords between adjacent nodes and not more than 5 cable and tools check

2 ± 5 Purlin spacing ruler check

3 vertical h/250 and not more than 15 with a theodolite or hanging wire and steel rule check

4 lateral bending L/1000 and not more than 10 cable and tools check

Note: h for the roof height, l is length of roof trusses, l for chords in the distance between adjacent nodes.

5 finished product protection

5.1 Installing the roof plate, slowly falling, no collision has installed steel roof, skylight frames and other steel components.

5.2 lifting damaged coating coating, to ensure the film thickness meets the requirements set out.

6 quality problems to be noticed

6.1 bolt hole wrong: no any hole or to welding, installation of such problems should report technical director, after consultation and design units, as required for processing.

6.2 field welding quality is not up to the design and specifications: welder must have a certificate of induction and should be numbered, welding parts by number check records, all weld by Visual inspection, where a site does not meet requirements, retesting after welding should be.

6.3 does not use mounting bolts, installed directly on high strength bolt installation must be installed according to specifications using bolt temporary fixing, after adjusting the fastening, high-strength bolts should be installed and replaced.

6.4 connected roof truss the base structures do not meet design requirements: when installing the full and final inspection and acceptance of steel roof truss, such as bearing structure does not meet the design requirements, not the acceptance formalities.

7 quality records

This standard shall meet the following quality records:

7.1 drawings of steel structures, design changes, record of negotiation.

7.2 installation connected with the steel, materials and coatings materials quality certificate or test report and re-test.

7.3 installation process engineering-related documents.

7.4 the welding quality inspection reports.

7.5 installation inspection records and quality assessment for installation information.

7.6 data after installation of steel structure painting.