GB 51210-2016 English PDF

GB 51210-2016: Unified standard for safety of scaffold in construction
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GB 51210-2016
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
UDC
P GB 51210-2016
Unified standard for safety of scaffold in construction
ISSUED ON: DECEMBER 02, 2016
IMPLEMENTED ON: JULY 01, 2017
Issued by: Ministry of Housing and Urban-Rural Development of the People's
Republic of China
General Administration of Quality Supervision, Inspection and
Quarantine of PRC.
Table of Contents
Foreword ... 5
1 General provisions ... 8
2 Terms and symbols ... 8
2.1 Terms ... 8
2.2 Symbols ... 10
3 Basic requirements ... 14
3.1 General requirements ... 14
3.2 Safety levels and safety factors ... 14
4 Materials and accessories ... 16
5 Load ... 20
5.1 Load classification and normal value ... 20
5.2 Load combination ... 22
6 Design ... 24
6.1 General requirements ... 24
6.2 Ultimate limit state ... 29
6.3 Serviceability limit state ... 40
7 Structural testing and analysis ... 41
7.1 General requirements ... 41
7.2 Frame test and analysis ... 44
7.3 Testing and analysis of accessories ... 46
8 Detailing requirements ... 47
8.1 General requirements ... 47
8.2 Operation scaffold ... 48
8.3 Shoring scaffold ... 50
9 Installation and dismantlement ... 54
10 Quality control ... 56
11 Safety management ... 58
11.1 General requirements ... 58
11.2 Safety requirements ... 59
Appendix A Mechanics testing methods of scaffold ... 61
A.1 Mechanics testing methods of accessories ... 61
A.2 Mechanics testing methods of scaffold structure ... 69
Explanation of wording in this standard ... 76
List of quoted standards ... 77
Unified standard for safety of scaffold in construction
1 General provisions
1.0.1 This standard is formulated in order to unify the design, construction, use,
management of construction scaffolding and ensure that it is technologically advanced,
safe, applicable, economical, reasonable.
1.0.2 This standard applies to the design, construction, use, management of scaffolding
for housing construction projects and municipal engineering construction.
1.0.3 In addition to complying with this standard, the design, construction, use,
management of construction scaffolding shall also comply with the relevant national
standards.
2 Terms and symbols
2.1 Terms
2.1.1 Scaffold
It is a structural frame composed of rods or structural units and accessories that are
reliably connected, can withstand corresponding loads, has safety protection functions,
provides operating conditions for building construction. It includes operation scaffold
and shoring scaffold.
2.1.2 Operation scaffold
Scaffolding which is composed of rods or structural units and accessories through
reliable connections, supported on the ground, buildings or attached to engineering
structures, to provide a working platform and safety protection for construction. It
includes floor-standing operation scaffold, cantilever scaffold, attached lifting scaffold,
etc. as formed by various types of rods (components), which are referred to as operation
scaffold.
2.1.3 Shoring scaffold
Scaffolding which is composed of rods or structural units and accessories that are
reliably connected and supported on the ground or structure, can withstand various
loads, has safety protection functions, provides support and working platforms for
building construction, including structural installation shoring scaffold, formwork
shoring scaffold for concrete construction, etc. as formed by various types of rods
(components), which are referred to as shoring scaffold.
2.1.4 Closed operation scaffold
An operation scaffold which uses materials such as dense mesh safety nets or steel wire
mesh to cover the entire outer facade.
2.1.5 Open operation scaffold
An operation scaffold which has an unobstructed non-enclosed outer facade.
2.1.6 Compositive safety factor
The overall safety factor of a scaffolding structure or main components, which is the
ratio -- of the ultimate bearing capacity of the scaffolding structure or components to
its design bearing capacity.
2.1.7 Normal value of geometrical parameter
The nominal value of the geometric parameters determined by the design, or the average
value of the geometric parameters determined by statistical probability distribution
based on the actual measurement results.
2.1.8 Scaffold detailing
The structural form, connection method, mutual relationship of the scaffold, which is
composed of frame members, structural units, accessories.
2.1.9 Scaffold structure test
A test to evaluate the mechanical properties of the scaffolding structure or main
components, through the test method of applied load.
2.1.10 Scaffold model test
A scaffold structural performance test, which is conducted using a prototype sample
with the same size and structure as the typical structural unit of the actual scaffold.
2.1.11 Scaffold unit structure test
Scaffold structure test, which is carried out using the same materials and components
as the scaffolding used in the project and setting up the test frame according to specific
structural requirements.
grade steel in the current national standard "Carbon structural steels" GB/T 700. The
thickness of the steel plate of the stamped steel scaffold planking shall not be less than
1.5 mm; the diameter of the inscribed circle of the planking punching hole shall be less
than 25 mm.
4.0.7 The base plate and base jack shall be processed and manufactured after design
and calculation; their materials shall comply with the steel grade Q235 requirements of
current national standards "Carbon structural steels" GB/T 700, or the steel grade Q345
requirements of "High strength low alloy structural steels" GB/T 1591. Meanwhile it
shall also comply with the following requirements:
1 The thickness of the steel base plate shall not be less than 6 mm; the thickness of
the U-shaped steel base jack shall not be less than 5 mm. The steel plate and the
screw shall be circumferentially welded. The height of the weld shall not be less
than the thickness of the steel plate; stiffening plates should be provided;
2 The fitting tolerance -- of the adjustable base plate and adjustable base jack inserted
into the steel pipe of the scaffolding standard -- shall be less than 2.5 mm;
3 The bearing capacity of the adjustable base plate and adjustable base jack, when
the screw rod meshes with the adjustable nut, shall be higher than that of the
adjustable base plate and adjustable base jack. The number of teeth meshing
between the screw rod and the adjusting nut shall be determined through
calculation. The thickness of the nut shall not be less than 30 mm.
4.0.8 The standard values of the geometric parameters of materials and accessories shall
adopt the nominal values specified in the design; the measured average value of the
geometric parameters of factory-produced accessories shall comply with the design
nominal values.
4.0.9 The materials of steel lifting rings or embedded anchor bolts shall comply with
the provisions of the current national standard "Code for design of concrete structures"
GB 50010.
4.0.10 The wire ropes used in scaffolding shall comply with the requirements of current
national standards "Steel wire ropes for general purpose" GB/T 20118, "Quality steel
wire ropes" GB/T 8918, "General purpose thimbles for use with steel wire ropes" GB/T
5974.1, "Wire rope grips" GB/T 5976.
4.0.11 The structural connection materials of metal scaffolding shall comply with the
following requirements:
1 The welding rods used for manual welding shall comply with the current national
standards "Covered electrodes for manual metal arc welding of non-alloy and fine
grain steels" GB/T 5117 or "Covered electrodes for manual metal arc welding of
creep-resisting steels" GB/T 5118. The type of welding rod selected shall be
compatible with the physical properties of metal being welded.
2 The welding electrodes used for automatic or semi-automatic welding shall comply
with the current national standards "Steel wires for melt welding" GB/T 14957,
"Welding electrodes and rods for gas shielding arc welding of carbon and low
alloy steel" GB/T 8110, "Carbon steel flux cored electrodes for arc welding"
GB/T 10045, "Low alloy steel flux cored electrodes for arc welding" GB/T 17493.
The selected welding electrode and flux shall be compatible with the physical
properties of the metal to be welded.
3 Ordinary bolts shall comply with the provisions of the current national standard
"Hexagon head bolts - Product grade C" GB/T 5780; their mechanical properties
shall comply with the provisions of the current national standard "Mechanical
properties of fasteners - Bolts, screws and studs" GB/T 3098.1.
4.0.12 The connectors of the scaffolding buckle-type connection and socket-type
connection shall have measures to prevent withdrawal or falling off.
4.0.13 Maintenance and inspection criteria shall be formulated for scaffolding rods and
accessories used for turnover. After each installation and disassembly cycle, they shall
be inspected, classified, maintained, serviced in a timely manner; unqualified products
shall be scrapped in a timely manner.
4.0.14 Scaffolding accessories shall have good interchangeability and be reusable. The
exit-factory quality of accessories shall meet the requirements of the current relevant
national product standards. The appearance quality of rods and accessories shall comply
with the following requirements:
1 Do not use steel pipes with cracks, creases, obvious surface dents, or severe
corrosion;
2 The surface of the casting shall be smooth, without defects such as blisters, pores,
cracks, pouring and riser residues; any sand adhering to the surface shall be
removed;
3 Stamping parts must not have burrs, cracks, obvious deformation, oxide scale or
other defects;
4 The welds of the welded parts shall be full; the welding slag shall be removed;
there shall be no defects such as incomplete penetration, slag inclusions, overlap,
cracks, etc.
4.0.15 Factory-made accessories shall have the manufacturer’s logo.
5 Load
5.1 Load classification and normal value
5.1.1 The load acting on the scaffold shall be divided into permanent load and variable
load.
5.1.2 The permanent load of the scaffolding shall include the following items:
1 The self-weight of the scaffolding structural components;
2 The self-weight of scaffold planking, safety nets, guardrails and other accessories;
3 The self-weight of the support system of the shoring scaffold;
4 The self-weight of the building structural materials and stacked materials on the
shoring scaffold;
5 Other loads that can be calculated as permanent loads.
5.1.3 The variable load of the scaffold shall include the following items:
1 Construction load;
2 Wind load;
3 Other variable loads.
5.1.4 The standard value of the permanent load of the scaffold shall comply with the
following requirements:
1 The self-weight value of materials and accessories can be taken as the standard
load value according to the current national standard "Load code for the design
of building structures" GB 50009;
2 For products such as tools and mechanical equipment, the load standard value can
be determined according to the general theoretical weight and relevant standards;
3 Representative sampling measurements can be taken and mathematical statistical
analysis can be carried out. The measured average value plus 2 times the mean
square error can be used as the standard load value.
5.1.5 The standard value of the variable load of scaffold shall comply with the following
requirements:
1 The standard value of the construction load on the operating layer of the operation
strength, or fail due to slippage of connecting nodes, or are unsuitable for
continued load-bearing due to excessive deformation;
2) The entire scaffolding structure or part of it is out of balance;
3) The scaffolding structure is transformed into a mobile system;
4) The overall or partial rods of the scaffolding structure are unstable;
5) The foundation loses its ability to continue bearing load.
2 When the scaffold appears in one of the following conditions, it shall be judged to
have exceeded the normal use limit condition:
1) Deformation that affects normal use;
2) Other states that affect normal use.
6.1.3 Scaffolding shall be designed according to normal installation and normal use
conditions; temporary effects, accidental effects, seismic loads may not be taken into
account.
6.1.4 The design calculation content of scaffold shall be determined based on factors
such as scaffold structure, installation location, usage function, load, etc. Calculations
for floor-landing operation scaffold and shoring scaffold shall include the following
content:
1 Floor-standing operation scaffold:
1) Bending strength and deflection of horizontal rods, as well as node connection
strength;
2) Stable bearing capacity of the standards;
3) Foundation bearing capacity;
4) Strength, stable bearing capacity, connection strength of tie members;
5) Bearing capacity and connection strength of wind ropes.
2 Shoring scaffold:
1) Bending strength and deflection of horizontal members, as well as node
connection strength;
2) Stable bearing capacity of standard;
3) The scaffold’s ability to resist overturning;
Where:
Md - Design value of bending moment of bending members of shoring scaffold
(Nꞏmm);
ΣMGk - The sum of the standard bending moment values of the bending members of
the shoring scaffold caused by the permanent load (N·mm);
ΣMQk - The sum of the standard bending moment values of the bending members of
the shoring scaffold caused by variable loads (N·mm);
Ψc - The variable load combination value factor, which shall be used in accordance
with the current national standard "Load code for the design of building structures"
GB 50009.
6.2.10 The calculation of the stable bearing capacity of shoring scaffold standards
(standards of gate s...