Article 1.0.1 This Specification is formulated with view to implementing national technical and economic policies in the design and construction of steel structure of tall building, to achieving technical advancement, economic rationality, safety and usability, and to ensuring quality thereof.
Article 1.0.2 This Specification is applicable to design and construction of steel structure of Class B or below high buildings, whose height and structure type are in accordance with those without seismic precaution and with precautionary intensity between Intensity 6 and Intensity 9 (hereinafter referred to as Intensity 6~Intensity 9) as specified in Table 1.0.2.
Table 1.0.2 Applicable Height of Steel Structure and Tall Building with Concrete Shear Wall Steel Structure (m)
... ...
... ...
Note: The applicable height refers to the height of regular structure, calculated from the outdoor floor to the building cornice.
Article 1.0.3 In the design of steel structure of tall building, the structural type shall be selected appropriately according to the characteristics of tall building and taking comprehensive consideration of buildings' use function, load nature, material supply, manufacture and installation; as for the structure selection and design of the construction and node, the structural system and plane and evaluation arrangement with good seismic and wind-resistant performance and economy and rationality shall be preferred.
Article 1.0.4 The steel structure with concrete shear wall shall also meet the requirements of current standard of the Nation "Specification for Design and Construction of Reinforced Concrete Tall Building".
Article 1.0.5 The steel structure of high buildings under seismic precaution may be classified into Classes A, B, C and D according to importance of the use function. The division shall meet the requirements of the current national standard "Standard for classification of Seismic Protection of Structure" (GB 50233).
Article 1.0.6 The seismic design of steel structure of tall building shall meet the following requirements:
I. Class A buildings shall be subjected to the seismic action calculation in accordance with specialized seismic ground motion parameter;
II. The Class C buildings situated at Classes I-III sites according to Intensity 6 precaution may not be subjected to the seismic action calculation;
III. The Class C buildings situated at Class IV according to Intensity 6 precaution, Class B buildings in Intensity 6 precaution and Class B and Class C buildings in Intensity 7~9 Intensity precautions shall be subjected to the seismic action calculation according to the precautionary intensity of this area;
IV. The buildings in Intensity 6 precaution may not be subjected to the structural calculation under the rare earthquake action.
Chapter 2 Materials
Article 2.0.1 The steel of steel structure of tall building should adopt Q235 Grades B, C, D carbon structural steels and Q345 Grades B, C, D, E low alloy high tensile structural steels. The quality standard thereof shall be in accordance with the requirements of the current national standards "Carbon Structural Steels" (GB 700) and "High Strength Low Alloy Structural Steels" (GB/T 1591). The steel of other grades may be adopted where the reliable reference is provided.
Article 2.0.2 The steel of the load bearing members shall be selected according to the structure importance, load characteristics, connection method, ambient temperature and position where the members are located in terms of the grades and materials; the steel shall have qualified tensile strength, elongation, yield point, cold bending test and impact toughness and the sulfur and phosphorus content shall be in accordance with the limit. The butt weld structure shall ensure that the carbon content limit is qualified.
Article 2.0.3 The yield ratio of seismic structure steel shall not be less than 1.2; the obvious yield step shall be provided; the elongation shall be greater than 20%; good weldability shall be provided.
Article 2.0.4 The steel performance shall be resistant to atmospheric corrosion and cryogenic cold brittleness where the load bearing structure is exposed and at the low temperature.
Article 2.0.5 The welded node shall be conducted according to those specified in the current national standard "Steel Plate with Through-thickness Characteristics" (GB 5313) where the plate is greater than or equal to 50mm thick and bears the tensile force along the plate thickness direction; the percentage reduction of area in the direction of the mezzanine board thickness shall not be less than the permissible value specified in Grade Z15 in this standard.
Article 2.0.6 The design steel strength adopted by the structure shall not be less than the requirements of Table 2.0.6.
Article 2.0.7 The physical performance of steel shall be in accordance with the requirements of Article 3.2.3 in the current national standard "Specifications for the Design of Steel Structures" (GBJ 17).
The steel grade and class and additional guarantee requirements for Z-direction performance shall be indicated in the design document of the steel structure of tall building and the order document of the steels.
