GB 50017-2017 (GB50017-2017)

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GB 50017-2017: PDF in English

GB 50017-2017
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
UDC
P GB 50017-2017
Standard for design of steel structures
ISSUED ON. DECEMBER 12, 2017
IMPLEMENTED ON. JULY 01, 2018
Issued by. Ministry of Housing and Urban-Rural Development of PRC;
General Administration of Quality Supervision Inspection and
Quarantine of PRC.
Table of Contents
Foreword ... 8 
1 General provisions ... 13 
2 Terms and symbols ... 14 
2.1 Terms ... 14 
2.2 Symbols ... 18 
3 General requirements ... 24 
3.1 General requirements... 24 
3.2 Structural systems ... 27 
3.3 Actions ... 28 
3.4 Requirements of deformation for structures and members ... 30 
3.5 Classification of sections ... 30 
4 Material ... 33 
4.1 Structural steel designations and standards ... 33 
4.2 Connections and fasteners materials and standards ... 33 
4.3 Selection of materials ... 35 
4.4 Design strength and parameters ... 37 
5 Structural analysis and stability design ... 47 
5.1 General requirements... 47 
5.2 Initial imperfections... 49 
5.3 First-order elastic analysis and design ... 52 
5.4 Second-order P-Δ elastic analysis and design ... 52 
5.5 Direct analysis method of design ... 53 
6 Flexural members ... 57 
6.1 Shear and flexural strength ... 57 
6.2 Flexural-torsional stability of beams ... 60 
6.3 Plate stability ... 63 
6.4 Design of beams considering post-buckling strength of webs ... 71 
6.5 Strengthening of openings ... 75 
6.6 Detailing ... 76 
7 Axially loaded members ... 78 
7.1 Strength calculation of cross-sections ... 78 
7.2 Stability calculation of members under axial compression ... 79 
7.3 Local stability and post-buckling strength of solid-web members under axial
compression ... 93 
7.4 Effective length and allowable slenderness ratio of members under axial
compression ... 97 
7.5 Bracing of members under axial compression ... 103 
7.6 Special cases of trusses and tower members ... 105 
8 Members under combined axial force and bending ... 108 
8.1 Strength calculations of cross-sections ... 108 
8.2 Stability calculation of members ... 111 
8.3 Effective length of frame columns ... 118 
8.4 Local stability and post-buckling strength of beam-columns ... 125 
8.5 Truss members subjected to second-order moments ... 128 
9 Stiffened steel shear walls ... 130 
9.1 General requirements... 130 
9.2 Design of stiffened steel shear walls ... 130 
9.3 Detailing ... 133 
10 Plastic design and provisions for design using moment redistribution ... 135 
10.1 General requirements... 135 
10.2 Provisions for design using moment redistribution ... 136 
10.3 Calculation of member strength and stability ... 137 
10.4 Slenderness limitations and detailing ... 138 
11 Connections ... 141 
11.1 General requirements ... 141 
11.2 Calculation of welded connections ... 143 
11.3 Detailing requirements of welded connections ... 148 
11.4 Calculation of fasteners ... 153 
11.5 Detailing requirements of fasteners ... 158 
11.6 Pin connections ... 161 
11.7 Details of flanged connections for steel tubes ... 164 
12 Joints ... 165 
12.1 General requirements... 165 
12.2 Connecting plate joints ... 165 
12.3 Beam-column joints ... 170 
12.4 Cast steel joints ... 175 
12.5 Pre-stressed cable joints ... 176 
12.6 Bearings ... 176 
12.7 Column footing ... 179 
13 Steel tubular joints ... 186 
13.1 General requirements... 186 
13.2 Detail requirements ... 187 
13.3 Design of unstiffened and stiffened CHS joints ... 192 
13.4 Design of unstiffened and stiffened RHS joints ... 212 
14 Composite steel and concrete beams ... 224 
14.1 General requirements... 224 
14.2 Design of composite beams ... 227 
14.3 Calculation of shear connections ... 231 
14.4 Calculation of deflection ... 234 
14.5 Calculation of concrete crack width at hogging moment region ... 236 
14.6 Calculation of longitudinal shear ... 237 
14.7 Detailing provisions ... 239 
15 Concrete-filled steel tubular columns and joints ... 242 
15.1 General requirements... 242 
15.2 Rectangular concrete-filled steel tubular members ... 242 
15.3 Round concrete-filled steel tubular members ... 243 
15.4 Beam-column joints ... 243 
16 Design for fatigue and brittle fracture ... 245 
16.1 General requirements... 245 
16.2 Design for fatigue ... 245 
16.3 Detailing requirements ... 252 
16.4 Prevention of brittle fracture ... 256 
17 Seismic design of steel structural members ... 258 
17.1 General requirements... 258 
17.2 Design requirements ... 262 
17.3 Connections and details ... 277 
18 Protection of steel structures ... 286 
18.1 Fire-resistance design ... 286 
18.2 Corrosion prevention design ... 286 
18.3 Temperature insulation ... 289 
Appendix A Common structural systems ... 290 
Appendix B Limits of deflection for structures and flexural members ... 293 
Appendix C Overall stability of beams ... 298 
Appendix D Stability coefficients of members under axial compression ... 304 
Appendix E Effective length factors of columns ... 309 
Appendix F Elastic buckling stresses for stiffened steel shear walls ... 318 
Appendix G Buckling calculation of truss connecting plate under diagonal
compression... 327 
Appendix H Classifications of unstiffened tubular joints in terms of rigidity 329 
Appendix J Fatigue design of composite steel and concrete beams ... 332 
Appendix K Design values for compressive and shear strength of composite
round concrete-filled steel tubes ... 334 
Explanation of wording in this standard ... 343 
List of quoted standards ... 344 
Standard for design of steel structures
1 General provisions
1.0.1 To implement the national technical and economic policies in the design
of steel structures, to achieve advanced technology, safety and application,
economic rationality, and quality assurance, this standard is hereby formulated.
1.0.2 This standard applies to the design of steel structures for industrial & civil
buildings as well as general structures.
1.0.3 In addition to complying with this standard, the design of steel structure
shall also comply with the provisions of relevant national standards.
2 Terms and symbols
2.1 Terms
2.1.1 Brittle fracture
The sudden fracture of structure or member which does not exhibit a plastic
deformation of alarming nature under the tensile stress.
2.1.2 First-order elastic analysis
The establishment of balancing conditions in accordance with the undeformed
structure as well as the analysis of structure’s internal force and displacement
by elastic phases, which does not consider the impacts of the geometric
nonlinearity on the structure’s internal force and deformation.
2.1.3 Second-order P-Δ elastic analysis
The establishment of balancing conditions in accordance with the displaced
structure as well as the analysis of structure’s internal force and displacement
by elastic phases, which only considers the impacts of the initial overall defect
of the structure and the geometric nonlinearity on the structure’s internal force
and deformation.
2.1.4 direct analysis method of design
The design method of using the overall structural system as an object to
perform the second-order nonlinear analysis, which directly considers the
factors of initial geometric defects, residual stress, material nonlinearity, joint
stiffness and so on that have significant influence on structural stability and
strength performance.
2.1.5 Buckling
Another state of significant deformation of the structure, member or steel plate
along the direction of weaker stiffness which reaches the critical state of bearing.
2.1.6 Post-buckling strength of steel plate
The capability of steel plate to continuously withstand larger load after it is
buckled.
2.1.7 Normalized slenderness ratio
A parameter, of which the value is equal to the square root of the quotient of the
bending, shearing or compressive yield strength of the steel AND the
corresponding flexural, shear or compressive elastic buckling stress of the
member or steel plate.
2.1.8 Overall stability
The capability of a member or structure to remain stable as a whole under load.
2.1.9 Effective width
When calculating the post-buckling ultimate strength of the steel plate, the
resulting reduced width which is obtained by using the uniformly distributed
yield strength to equivalent the width of the steel plate which is subject to the
non-uniformly distributed ultimate stress.
2.1.10 Effective width factor
The ratio of the effective width to the actual width of the steel plate.
2.1.11 Effective length ratio
Coefficients associated with the buckling mode of the member and the
rotational constraints at both ends.
2.1.12 Effective length
The length used to calculate stability, the value of which is equal to the product
of the geometric length of the member between its effective constraint points
and the effective length ratio.
2.1.13 Slenderness ratio
The ratio of the effective length of the member to the turning radius of the
member section.
2.1.14 Equivalent slenderness ratio
In the overall stability calculation of the axially loaded members, in accordance
with the principles of equal critical force, the slenderness ratio corresponding to
the calculation which converts the lattice members to solid-web members, or
the calculation which converts the bending torsional and torsional instability into
bending instability calculations.
2.1.15 Nodal bracing force
The lateral force which is used for bracing along the buckling direction of the
braced members (or the compressed flange of the member), at the lateral
support which is provided to reduce the free length of the compressed member
(or the compressed flange of the member).
2.1.16 Unbraced frame
The structure which uses the bending resistance of the joint and the member to
resist the load.
2.1.17 Bracing structure
In the plane in which the beam-column members are located, the structure
which has the obliquely-arranged bracing member to support the axial stiffness
and to resist the lateral load.
2.1.18 Frame-bracing structure
The structure of the anti-lateral force system which is composed of a frame and
a bracing.
2.1.19 Frame braced with strong bracing system
In the frame-bracing structure, if the bracing structure (bracing truss, shear wall,
cylinder, etc.) has a large lateral stiffness resistance, the frame can be regarded
as a frame without lateral displacement.
2.1.20 Leaning column
The column which is designed only to by axially loaded but does not consider
the lateral stiffness.
2.1.21 Panel zone
The region of the rigid joints of the frame beam-column and the column webs
which are provided with stiffeners or partitions on the upper and lower sides of
the beam height range.
2.1.22 Spherical steel bearing
The hinged bearing or movable bearing the steel spherical surface of which can
be rotated in any direction at the bearing.
2.1.23 Steel-plate shear wall
A steel plate which is placed between the frame beam-column to withstand the
horizontal shear in the frame.
2.1.24 Chord member
In a steel tubular structure member, a tube member which is continuously cut
through at the joint, such as a chord in a truss.
2.1.25 Branch member
In a steel tubular structure, a tube member that is disconnected at a joint and
connected to a chord member, such as a web member in a truss to connect to
a chord member.
2.1.26 Gap joint
A tube joint the two branch members of which depart for a certain distance.
2.1.27 Overlap joint
At the steel-tube joint, the joint where the two branch members overlap each
other.
2.1.28 Uniplanar joint
A joint in which the branch member and the chord member are connected to
each other in the same plane.
2.1.29 Multiplanar joint
A tube joint formed by connecting a plurality of branch members in different
planes to a chord member.
2.1.30 Welded section
A section made of a steel plate (or profile steel) through welding.
2.1.31 Composite steel and concrete beam
A beam which is formed by the concrete flange and steel beam through the
shear connections and can be integrally loaded.
2.1.32 Bracing system
An anti-lateral force system which consists of beams (including foundation
beams) and columns that support and transmit their internal forces.
2.1.33 Link
In an eccentric bracing frame structure, a beam section which is located
between the two oblique bracing ends or a beam section which is located
between an oblique bracing end and the column.
2.1.34 Concentrically braced frame
A frame whose oblique bracing intersects with the frame beam-column at one
point.
2.1.35 Eccentrically braced frame
4 Material
4.1 Structural steel designations and standards
4.1.1 Steels should be Q235, Q345, Q390, Q420, Q460 and Q345GJ steels.
The quality shall comply with the provisions of the current national standards
“Carbon structural steels” GB/T 700, “High strength low alloy structural steels”
GB/T 1591, and “Steel plates for building structure” GB/T 19879. The
specifications, shape, weight and allowable deviation of steel plates, hot-rolled
I-beams, channel steels, angle-steels, H-shape profile steels, steel-tubes, and
other profiles for structural use shall comply with the provisions of relevant
national standards.
4.1.2 When the welded load-bearing structure uses the Z-direction steel to
prevent laminar tearing of steel, the quality shall comply with the current
national standard “Steel plates with through-thickness characteristics” GB/T
5313.
4.1.3 For load-bearing structures that are exposed in open-air and have special
requirements for corrosion resistance or are in an aggressive medium
environment, it may use the weather-proof structural steel of designation
Q235NH, Q355NH and Q415NH, the quality of which shall comply with the
current national standard “Atmospheric corrosion resisting structural steel”
GB/T 4171.
4.1.4 The quality of steel castings for non-welded structures shall comply with
the current national standard “Carbon steel castings for general engineering
purpose” GB/T 11352. The quality of steel castings for welded structures shall
comply with the current national standard “Steel casting suitable for welded
structure” GB/T 7659.
4.1.5 When using the steels of other designations which are not listed in this
standard, it should perform statistical analysis in accordance with the current
national standard “Unified standard for reliability design of building structures”
GB 50068, to study and determine its design indicators and scope of application.
4.2 Connections and fasteners materials and standards
4.2.1 Welding materials for steel structures shall comply with the following
requirements.
1 The electrodes used for manual welding shall comply with the current
national standard “Covered electrodes for manual metal arc welding of
non-alloy and fine grain steels” GB/T 5117, the selected electrode model
its quality shall comply with the industry standard “Hot-rolled round carbon
steel bars and rods for standard parts” YB/T 4155-2006.
4.3 Selection of materials
4.3.1 The selection of structural steel shall follow the principle of reliable
technology and economic rationality, comprehensively consider the importance
of structure, load characteristics, structural form, stress state, connection
method, working environment, steel thickness and price, etc., select suitable
steel designation and material guarantee items.
4.3.2 The steel used for the load-bearing structure shall have the
qualification guarantee of yield strength, tensile strength, elongation after
fracture and the content of sulfur and phosphorus. For the welding
structure, it shall also have the qualification guarantee for carbon
equivalent. The steel used for the welded load-bearing structure and the
important non-welded load-bearing structure shall have the qualification
guarantee for the cold-bending test; the steel used for the member
directly subjected to the dynamic load or the fatigue verification shall also
have the qualification guarantee for impact toughness.
4.3.3 The selection of steel’s quality grades shall comply with the following
requirements.
1 Grade A steel can only be used for structures that have a working
temperature above 0 °C and do not require fatigue verification. Q235 steel
should not be used for welding structure.
2 The steel for welding structures which require fatigue verification shall
meet the following requirements.
1) When the working temperature is higher than 0 °C, its quality grade shall
not be lower than grade B;
2) When the working temperature is not higher than 0 °C but higher than -
20 °C, the Q235 and Q345 steel shall not be lower than grade C; the
Q390, Q420 and Q460 steel shall not be lower than grade D;
3) When the working temperature is not higher than -20 °C, the Q235 steel
and Q345 steel shall not be lower than grade D; the Q390 steel, Q420
steel, and Q460 steel shall be grade E.
3 For the non-welded structure which requires fatigue verification, the steel’s
quality grade may be reduced by one grade as compared with the above-
mentioned welded structure, but it shall be not lower than grade B. For
crane beam of the intermediate working-system which has a lifting weight
11 Connections
11.1 General requirements
11.1.1 The method of connection of steel structural members shall be selected
in accordance with the conditions of the construction environment and the
nature of the force.
11.1.2 At the same connection location, it shall neither use common bolts nor
the connection which shares the pressure-type high-strength bolt and welding;
as the reinforcing measures in the reconstruction and expansion projects, it
may use the bolting-welding combined connection which may use the friction-
type high-strength bolts and the weld to jointly withstand the same action force,
its calculation and construction should comply with the provisions of clause 5.5
of “Technical specification for high strength bolt connections of steel structures”
JGJ 82-2011.
11.1.3 Grade C bolts should be used for the connections that are tensioned
along their bar axis, or may be used for shear connections in the following cases.
1 The secondary connection in a structure subjected to static loads or
indirectly subjected to dynamic loads;
2 The connection of a detachable structure subjected to static loads;
3 The mounting connection used for temporary fixing members.
11.1.4 Countersunk head and semi-countersunk head rivets shall not be used
for the connection which is tensioned along its bar axis direction.
11.1.5 The design of welded-connection construction of steel structure shall
comply with the following requirements.
1 Minimize the number and size of welds;
2 The arrangement of welds should be symmetrical to the centroid of the
member’s section;
3 The joint area has enough space for welding operation and post-weld
testing;
4 It shall avoid dense weld and two-way, three-way intersections;
5 The weld position shall avoid the maximum stress area;
6 Weld connection shall be selected to ensure equal-strength matching;
when steels of different strengths are connected, it may use the welding
materials which match the low-strength steel.
11.1.6 The quality grade of the weld shall be selected based on the importance
of the structure, load characteristics, weld form, working environment and
stress state in accordance with the following principles.
1 In the members that are subjected to dynamic loads and require fatigue
verification, the welds that require equal-strength connection with the base
metal shall be welded through, the quality grade shall comply with the
following requirements.
1) For the lateral butt weld or the combined weld of T-butt joint and the
angle joint whose force is perpendicular to the weld’s length direction, it
shall be grade I when it is tensioned, or not be lower than grade II when
compressed;
2) The longitudinal butt welds whose force is parallel to the weld’s length
direction shall not be lower than the stage II;
3) The weld at the T-shaped connection part between the web and the
upper flange of the crane beam of heavy-duty working-system (A6 ~ A8)
and the medium-duty working-system (A4, A5) which has a lifting weight
Q ≥ 50t, as well as between the upper chord of the crane truss and the
joint plate shall be welded through, the weld form should be combined
weld of butt joint and angle joint, the quality grade shall be not lower
than grade II.
2 In areas where the operating temperature is equal to or lower than -20 °C,
the quality grade of the member’s butt weld shall not be lower than grade
II.
3 In the members that do not require fatigue verification, the butt welds that
are required to have equal-strength with the base metal should be welded
through, the quality grade shall not be lower than grade II when tensioned,
and shall not be lower than grade II when compressed.
4 For the partially weld-through butt welds, the angle weld, the T-shaped
connection location of the butt-joint and angle-joint combined weld, and
the angle weld of overlapped connection, the quality grade shall comply
with the following provisions.
1) For the structure which is directly subjected to dynamic load and
requires fatigue verification, the beam of the medium-duty working-
system crane which has a lifting weight equal to or greater than 50 t, the
beam-column, the bracket, and the other important joints, it shall be not
lower than grade II;
4 The stiffener or partition of the column’s web at the joint area of the beam-
column shall comply with the following requirements.
1) The cross-section size of the lateral stiffener shall be determined by
calculation, its thickness should not be less than the thickness of the
beam’s flange; its width shall meet the requirements of force
transmission, construction and limit slenderness ratio of the plate;
2) The upper surface of the lateral stiffener should be aligned with the
upper surface of the beam’s flange, and connected to the column’s
flange by a penetrated T-shaped butt weld. When the beam is connected
to the column of H-shaped section along the weak axis direction, that is,
it is perpendicularly connected to the web to for rigid connection, the
connection between the lateral stiffener and the column’s web should
use the penetrated butt weld;
3) The connection between the lateral partition and the column’s flange in
the box-shaped column should use the penetrated T-shaped butt weld.
For the weld which cannot use arc welding and the thickness of the
column’s wall panel is not less than 16 mm, it may use the fusion nozzle
electroslag;
4) When using the oblique stiffeners to reinforce the panel zone, the
stiffener and its connection shall be able to transmit the other shear force
than that can be undertaken by the column’s web; its section size shall
comply with the requirements for the force transmission and the limit
slenderness ratio of plate.
12.3.6 The beam-column’s rigid joint which uses the end-plate connection shall
comply with the following requirements.
1 End-plate should be the overhanging-type. The thickness of the end-plate
should not be less than the bolt diameter;
2 The thickness of the end-plate and the diameter of the bolt at the joints
shall be determined by calculation, it should take into account the
influence of prying force in the calculation;
3 For the column’s web in the joint area which is corresponding to the
location of the beam’s flange, it shall provide the lateral stiffener, the panel
zone which is surrounded by it and the column’s flange shall be subject to
the verification of shear strength in accordance with clause 12.3.3 of this
standard, it should provide the oblique stiffener for reinforcing purpose
when the strength is insufficient.
12.3.7 The joints connected by end-plates shall comply with the following
provisions.
12.4.6 The casting process shall ensure that the internal texture of the cast steel
joint is dense and uniform, the steel castings should be subjected to normalizing
or quenching-tempering heat treatment. The design documents shall indicate
the tolerance of the skin size of steel castings.
12.5 Pre-stressed cable joints
12.5.1 Tensile joints of prestressed high-strength cables shall ensure that the
joint tension zone has sufficient construction space for ease of construction
operation and reliable anchoring. The connection between the tensioned joint
of the prestressed cable and the principal structure shall consider the over-
tensioning as well as the actual stress of the cable at the loading phase, to
ensure safe connection.
12.5.2 Prestressed cable’s anchoring joints shall adopt anchorages with reliable
force transmission, low prestress loss and convenient construction, it shall
ensure the local compressive strength and stiffness of the anchorage zone. The
principal stressed bar and plate zone in the anchoring joint area shall be
subjected to stress analysis and connection calculation. The joint area shall
avoid overlapping welds, openings, etc.
12.5.3 The prestressed cable’s turning joints shall be provided with chutes or
channels. It may apply lubricants or gaskets in the chutes or channels, or use
materials with low friction coefficient; it shall verify the local compressive
strength of the turning joint, and take reinforcing measures.
12.6 Bearings
12.6.1 For the beam or truss whose flat-plate bearing braced on the masonry
or the concrete, it shall verify the compressive strength of the lower masonry or
concrete, the base-plate’s thickness shall be calculated in accordance with the
bending moment produced by the bearing’s reaction force against the base-
plate, and it should be not less than 12 mm.
When the end of the beam’s end bracing stiffener is calculated in accordance
with the design value of the end surface’s compressive strength, it shall be
planed and jacked tightly, wherein the overhanging length of the flange’s
stiffener shall be not more than 2 times its thickness, and it should take position-
limit measures (Figure 12.6.1).
core, the base and the box on the spherical bearing shall be processed by cast
steels, the sliding plane shall take the corresponding lubricating measures, the
bearing as a whole shall take dust-proof and rust-proof measures.
12.7 Column footing
I General provisions
12.7.1 The column footing of multi-floored high-rise structural frame columns
can be buried column footing, plug-in column footing and outer-wrapped
column footing. The multi-floored structural frame columns can also adopt
exposed column footings. The single-floored workshop’s rigidly connected
column footing may be the plug-in column footing and exposed column footing;
the hinged column footing should be exposed type.
12.7.2 For the outer-wrapped, buried and plug-in column footing, it shall not
apply paint within the range of contact between steel column and concrete;
when installing the column footing, it shall use the grinding wheel to clean the
soil, oil stain, rust, and welding slag from the surface of the steel column.
12.7.3 When the end of the axial compression column or the bending-flexural
column is a milling-flat end, the maximum pressure of the column body shall be
directly transmitted by the milling-flat end. The connection weld or bolt shall be
subject to shear calculation in accordance with 15% of the maximum pressure
and the maximum shear force, whichever is larger. When the bending-flexural
column has tensioned zone, the connection of such zone shall be calculated in
accordance with the maximum tensile force.
II Exposed column footing
12.7.4 Column footing anchors should not be used to withstand the horizontal
reaction force at the bottom of the column footing. This horizontal reaction force
is undertaken by the friction force between the base-plate and the concrete
foundation (the friction coefficient is 0.4) or by setting the shear key.
12.7.5 The size and thickness of the base-plate of the column footing shall be
determined in accordance with the bending moment at the column end, the
axial force, the bracing condition of the base-plate, the reaction force of the
concrete under the base-plate, and the structure of the column footing. The
anchor of the exposed column footing shall be determined by calculation based
on the environment in which it is used.
12.7.6 Column footing anchors shall have sufficient burial depth. When the
burial depth is limited or the anchorage of the anchor bolt is relatively long in
concrete, it may set the anchor plates or anchor beams.
3 The anchor bolts of column footing shall be set in accordance with the
constructional requirements, the diameter should not be less than 16 mm,
the anchorage length should not be less than 20 times its diameter;
4 It shall provide the horizontal stiffener or lateral diaphragm for the columns
at the top stirrups of the outer-wrapping concrete, its slenderness ratio
shall comply with the relevant provisions of clause 6.4 of this standard;
5 When the frame column is a round tube or a rectangular-tube, it shall pour
concrete in the tube, the strength grade shall not be less than that of the
foundation concrete. The concrete pouring height shall be higher than that
of the outer-wrapping concrete, meanwhile it should be not less than the
diameter of the round-tube or the long side of the rectangular-tube;
6 The verification of the bending and shear capacity of the outer-wrapping
reinforced concrete as well as the constructional requirements for the
tensioned rebar and stirrup shall comply with the relevant provisions of the
current national standard “Code for design of concrete structures” GB
50010. The length of the main rebar extending into the foundation ...
......
(Above excerpt was released on 2018-10-05, modified on 2021-06-07, translated/reviewed by: Wayne Zheng et al.)
Source: https://www.chinesestandard.net/PDF.aspx/GB50017-2017