1 scope
This technology is applicable to steel grid
with bolt-sphere joints, welding joints, weld plate joints of steel grid
structure of ground works.
2 construction preparation
2.1 materials:
2.1.1 steel grid assembled steel and
materials, high strength bolts, rods and other materials should comply with the
design requirements and shall have factory certification.
2.1.2 bolt-ball and welding, and
welding-ball and hollow Cone, sleeve, cover plate, truss rods, welded steel
joints and other semi-finished products should comply with the design
requirements and the corresponding provisions of the national standard.
2.1.2.1 bolt ball steel to make steel
structure wire table, must comply with the design requirements and the
corresponding material specifications and standards. Bolt is strictly
prohibited burning, cracking the ball and kind of hidden, finished the ball
must be on the maximum tensile strength test of the screw holes. Bolt shall
comply with quality requirements and test methods provided in table 5-14.
Bolt-ball method for the determination of
tolerances and table 5-14
Project tolerance (mm) method
Ball blank diameter d ≤ 120
+2.0-1.0
D>120 +3.0-1.5 using calipers, Vernier
calipers to check
The roundness of the ball d ≤ 120 1.5
D>120 2.5
3-bolt ± 0.20 ball screw end and Center
distance measured with a Vernier caliper, mandrel, height gauge check
Two screws on the same axis d ≤ 120 0.20
Parallelism D>120 end 0.30 using Vernier
calipers, height gauge check
5 two adjacent ± 30 ' by measuring the
angle between the screw axis, height gauge mandrel, dividing head check
6 bolt end surface perpendicular to the
axis of the 0.5%r with a dial gauge
Note: r is the bolt end surface radius.
2.1.2.2 assembled with high strength bolt
steel must comply with the design requirements and the corresponding technical
standards. High strength bolts for steel grid structure must adopt the national
standards of the high strength large Hexagon head bolts for steel structure
under performance class 8.8S or 10.9S and should be checked according to the
corresponding requirements. Check for high strength bolt factory certification,
inspection and test reports, inspection re-inspection report. In front of the
assembled each surface hardness test of high strength bolts, no cracks and
damage. Method for the determination of tolerances and high strength bolts
shall conform to table 5-15 requirement.
Table 5-15 of the method for the
determination of tolerances and high strength bolts
Project tolerance (mm) method
1-thread length (t-pitch) +2T 0
2-bolt length +2T-0.8T
3 Groove ± 0.2 with tools, Vernier calipers
to check
4 keyway straightness <0.2
Position 5 of <0.5
2.1.2.3 assembled by welding of ductile
materials, specifications and quality, must comply with the design requirements
and the provisions of the relevant standard. Welding electrode and flux, wire
and shielding gas shall comply with the technical requirements and regulations.
Welded steel ball bearing ball factory certification and inspection reports.
Assembling welding ball should meet the requirements of table 5-16.
Tolerances and inspection method of welding
ball table 5-16
Project tolerance (mm) method
1 ball height flush with the surface of
sphere ± 0.5 using weld gauges along weld circumference equal parts take 8
points
2 ball diameter d ≤ 1.5 ± 1.5 with
calipers and Vernier calipers checked, each measurement to three
3 ball D>300 diameter ± 2.5 numerical
4 ball roundness d ≤ 300 w ≤ 1.5
calipers and Vernier calipers checked, each measuring three on each mutual
5 ball roundness D>300 ≤ 2.5 to 90 °, with the
average of three pairs of diameter difference meter
62 hemisphere counterpart unfitness ≤ 1.0 model
and Vernier calipers checked, each ball maximum misalignment
2.1.2.4 assembled steel grid plate, cone,
the steel sleeve, must comply with the design requirements and the appropriate
technical standards. Cover plate, cone, sleeve appearance of wood cracked, had
burned and oxidized. Cover plate, cone, bask in the quality requirements and
test methods should meet the requirements of table 5-17.
Seal plate, cone, the sleeve method for the
determination of tolerances and table 5-17
Project tolerance (mm) method
1 plate, cone aperture +0.5
+0.5-0.2 2 plate, cone bottom thickness
using Vernier calipers to check
3 plates, cone bottom two parallel 0.1 with
dial gauge, v-shaped block check
4 plates, coaxial cone hole and the pipe
installation steps of 0.2 with dial gauge, v-shaped block check
+0.2 0 5 cone wall thickness using Vernier
calipers to check
6 sleeve in the hole with the circumcircle
of coaxial degree 0.5 measured with a Vernier caliper, dial gauge, mandrel
check
7 sleeve length ± 0.2 using Vernier
calipers to check
8 sleeve ends perpendicular to the axis of
the 0.5%r measured with a Vernier caliper, dial gauge, mandrel test
Parallelism of sleeve 9 ends 0.3
Note: 1. Cover plate, cone, socket should
have conducted separate inspection and assessment.
2. r is the radius of the circumcircle of
the sleeve.
2.1.2.5 steel grid plate for assembling
welding, must comply with the design requirements and the appropriate technical
standards. Certificate of welding materials factory and the corresponding
technical standards. Assembling plate joints weld shall meet the design
requirements. The quality requirements and test methods shall be in accordance
with table 5-18 requirement.
Steel node method for the determination of
tolerances and table 5-18
Project tolerance (mm) method
1 Gusset Plate length and width ± 2.0mm
with a steel ruler to check
2 gusset 0.5mm thickness using Vernier
calipers to check
30 byte plate angle between ± 20 '
40 bytes between the plate and the cover
plate angle ± 20 ' standard angle gauge check
2.1.2.6 steel truss rod parts for
assembling the steel varieties, specifications, quality, must comply with the
design requirements and the appropriate technical standards. Steel bars and
plates, cone connection must conform to the design requirements, quality
standards must be consistent with the national standards of the steel structure
project construction and acceptance in the second level of quality standards.
Steel bar with cover plate or Cone weld strength test should be carried out,
its carrying capacity shall meet the design requirements. Steel pole of quality
requirements and test methods should meet the requirements of table 5-19.
-Tolerance and inspection methods table
5-19
Project tolerance (mm) method
1 making length ± 2 steel angle bar
examination
2-welded spherical grid structure of steel
bars production length ± 1
3 length of bolt ball steel bar unit ± 1
using tools and indicators to check
4 axis deflection L/1000 and Michael
Jackson-5
5 plate or Cone head perpendicular to the
pipe axis 0.5%r with dial gauge, v-shaped block check
Note: a rod length l, r radius at the end
of a plate or Cone head.
2.2 the main equipment
Welding machines, oxyacetylene equipment,
wheel saws, pipe cutting machines, steel tape measure, steel ruler, caliper,
thickness gauges, ultrasonic flaw detector, magnetic detector, hammers, wire
brushes, calipers, dial indicator detection instruments.
2.3 operating conditions:
2.3.1 assembling the welder must have a
welding test certificate, there is a corresponding qualification of the welding
material and welding station.
2.3.2 Assembly prior to installation site
safety facilities, fire prevention facilities. Assembled before the assembled
position detection, prevention of fetal movement and deformation. Assembling
position should remain the welding deformation of the right margin, preventing
Assembly Rod deformation, distortion.
2.3.3 Assembly former Member sizes, Groove
and weld gap should be in order.
2.3.4 familiar with the drawings,
preparation of the Assembly process, technical clarification.
2.3.5 before assembling, assembled with
high-strength bolts of hardness test them one by one, up to standard values can
be assembled.
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