1 General Provisions
1.0.1 This Code is formulated with a view to normalizing the design, fabrication, installation and acceptance of steel structure of light-weight building with gabled frames, achieving safety and usability, advanced technology, economy and rationality and ensuring quality.
1.0.2 This Code is applicable to single-story steel structure buildings with the height of building no greater than 18m, the height-width ratio less than 1, single-span or multi-span solid-web gabled frame as the load-bearing structure, light-weight roof, without bridge crane or with Class A1-A5 bridge crane at a lifting capacity of no greater than 20t or 3t suspension crane.
This Code is not applicable to buildings with high corrosive medium effect on the steel structure as specified in GB 50046 Code for Anticorrosion Design of Industrial Constructions.
1.0.3 Design, fabrication, installation and acceptance of the steel structure of light-weight building with gabled frames shall meet the provisions of both this Code and national current relevant standards.
2 Terms and Symbols
2.1 Terms
2.1.1 Light-weight building with gabled frames
The single-storey building that variable or constant section solid-web frame is adopted for the load-bearing structure and light-weight steel roof and light-weight exterior wall are adopted for the enclosure system.
2.1.2 Height of building
The average height from the outdoor ground to the roof. Where the roof slope angle is not greater than 10°, cornice height may be taken. Where the roof slope angle is greater than 10°, the average of the cornice height and the roof ridge height shall be taken. For single-slope building, where the roof slope angle is not greater than 10°, smaller cornice height may be taken.
2.1.3 Mezzanine
An indoor platform connected between one side and rigid frame column, which is generally arranged along the longitudinal direction of the building and few arranged along the gable.
2.1.4 Leaning stanchion
An axial compression member with the upper and lower ends hinged.
2.1.5 Diagonal brace
Bracing member for supporting the inclined beam and the compression flange of the column.
2.1.6 End wall column
The column arranged at the gable and for transferring the wind load on the gable to the horizontal brace of the roof.
2.1.7 Opening
The part which is not arranged with permanent effective enclosure on the exterior surfaces (wall surface and roof).
2.1.8 Open building
The building that at least 80% of each wall surface is the opening.
2.1.9 Partially enclosed building
The building that total area of the opening on the wall surface under external positive wind pressure exceeds that of the opening on its remaining exterior surfaces (wall surface and roof) and 10% the gross area of this wall, and opening ratio of the remaining exterior surfaces doesn't exceed 20%.
2.1.10 Enclosed building
The building without the opening in accordance with the definition of the partially enclosed building or open building in the enclosed space.
2.1.11 Edge strip
The zone at the building end and edge divided on the exterior wall and the roof during the determination of the coefficient for the wind load on the enclosure structure member and panel.
2.1.12 End zone
The zone at the building end and edge divided on the exterior wall and the roof during the determination of the coefficient for the wind load on the main rigid frame.
2.1.13 Middle zone
The zone not belonging to the edge strip and end zone divided on the exterior wall and the roof.
2.1.14 Effective wind load area
The effective area for bearing the wind load taken for the determination of the wind load coefficient.
2.2 Symbols
2.2.1 Action and effect
F - the concentrated load borne by the upper flange;
Mcr - the critical bending moment for elastic buckling of tapered beam;
Mr - the bending moment borne by two flanges;
Me - the bending moment borne by effective section of the member;
MfN - the bending moment borne by two flanges when bearing the pressure N concurrently;
N - the design value of axial tension or axial pressure;
Ncr - the Euler critical force;
Ns - the pressure generated by the tension field;
Nt - the design value of the tensile capacity of one high-strength bolt;
Nt2 - the design value of axial tension of one bolt in the second row inside the flange;
Rd - the design value of bearing capacity of structural member;
SE - the design value of load and seismic action effect combination when considering frequent seismic action;
SEhk - the effect of characteristic value of horizontal seismic action;
SEvk - the effect of characteristic value of vertical seismic action;
Sk - the characteristic value of snow load;
S0 - the reference snow pressure;
SGk - the characteristic value of permanent load effect;
SQk - the characteristic value of vertical variable load effect;
Swk - the characteristic value of wind load effect;
SGE - the effect of representative value of gravity load;
Vd - the design value of shear capacity of the web;
Vmax - the maximum shear force of the purlin;
Vx′,max, Vy′,max - the shear force generated by vertical load and horizontal load respectively;
Vy - the support reaction of the purlin;
W - the design value of total vertical load of the roof in load-carrying area borne by purlin brace within 1 column spacing;
wk - the characteristic value of wind load;
w0 - the reference wind pressure.
2.2.2 Material properties and resistance
E - the elastic modulus of steels;
f - the design value of strength of steels;
fv - the design value of the shear strength of steels;
ft - the design value of tensile strength of steels of the connected plate;
fwf - the design value of strength of the fillet weld;
G - the shear modulus of steels;
R1 - the rigidity corresponding to the shear deformation of panel zone;
R2 - the bending rigidity of connection.
2.2.3 Geometrical parameters
A0, A1 - the gross sectional areas of the sections on small end and large end respectively;
Ae - the effective sectional area;
Ael - the effective sectional area of large end;
Af - the sectional area of the member flange;
Ak - the sectional area of the diagonal brace bar;
An1 - the net sectional area of single bar;
Ap - the sectional area of the purlin;
Ast - the total sectional area of two diagonal stiffening ribs;
db - the height of inclined beam end or joint zone;
e1 - the distance from the shear center of the beam section to the centroid line of the purlin;
ew, ef - the distance from the bolt center to the web and the flange plate surface respectively;
h1 - the distance between the centers of the flange plates on the beam end;
hb - the height of snow load determined according to the reference snow pressure of the roof;
hc - the width of compression area of the web;
hd - the piling height of snow;
h0 - the height of straight section of the purlin web after deduction of the cold bending radius;
hr - the height difference of high and low roof;
hsT0, hsB0 - the distance from the middle surface of upper and lower flange of the section on small end to the shear center respectively;
hw - the height of the web;
hw1, hw0 - the height of web on the large and small ends of the tapered web respectively;
I1 - the inertia moment around the minor axis of the flange supported by the diagonal brace;
I2 - the inertia moment around the minor axis of the flange connected with the purlin;
Ip - the inertia moment around the major axis of the purlin section;
Iw0 - the inertia moment of warping of the section on small end;
Iwη - the equivalent inertia moment of warping of the tapered beam;
ix1 - the turning radius around the major axis of the section on large end;
Iy - the inertia moment around the minor axis of the tapered beam;
iy1 - the turning radius around the minor axis of the section on large end;
IyT, yB - the inertia moment around the minor axis of the compression flange and tension flange of the section with the maximum bending moment respectively;
J, Iy, Iw - the free torsion constant, inertia moment around the minor axis and inertia moment of warping of the section on large end respectively;
1 General Provisions
2 Terms and Symbols
2.1 Terms
2.2 Symbols
3 Basic Requirements of Structural Design
3.1 Design Principles
3.2 Choice of Materials
3.3 Deformation Limits
3.4 Structural Requirements
4 Loads and Load Combinations
4.1 General Requirements
4.2 Wind Load
4.3 Snow Load on Roof
4.4 Seismic Action
4.5 Effect of Load Combinations and Seismic Action
5 Types and Arrangement of Structure
5.1 Types of Structure
5.2 Arrangement of Structure
5.3 Girt Arrangement
6 Calculation and Analysis of Structure
6.1 Calculation of Gabled Frame
6.2 Analysis of Seismic Action
6.3 Analysis of Thermal Action
7 Design of Structural Members
7.1 Calculation of Frame Members
7.2 Calculation of End Wall Members
8 Design of Bracing
8.1 Principles for Bracing Design
8.2 Design of Longitudinal Bracing along Columns
8.3 Design of Transverse and Longitudinal Bracing along Roofs
8.4 Arrangement of Diagonal Brace
8.5 Connection Joint of Rod Brace with Frame
9 Design of Purlin and Girt
9.1 Design of Solid-web Purlin
9.2 Truss Purlin
9.3 Design of Tensioned Rod
9.4 Design of Girt
10 Design of Connection and Joint
10.1 Welding
10.2 Connection Design
11 Design of Enclosure System
11.1 Design of Roofing and Cladding
11.2 Isolation and Heat Preservation
11.3 Design of Roof Drainage
12 Protection of Steel Structure from Corrosion
12.1 General Requirements
12.2 Design of Fire Resistance
12.3 Coating
12.4 Requirements of Steel Structure on Antirust
13 Fabrication
13.1 General Requirements
13.2 Processing of Steel Member
13.3 Configuration and Geometry of Members
13.4 Welds for Members
14 Transportation, Erection and Acceptance
14.1 General Requirements
14.2 Erection and Correction
14.3 High-strength Bolts
14.4 Welding and Other Fasteners
14.5 Erection of Purlins and Girts
14.6 Erection of Enclosure System
14.7 Acceptance
Appendix A Effective Length of Frame Column
Explanation of Wording in This Code
List of Quoted Standards
