1.0.1 This code is formulated with view to implementing the national technical and economic policies in the design, member manufacturing and project construction of concrete filled steel tubular structures and realizing safety, applicability and economy.
1.0.2 This code is applicable to the design, member manufacturing and construction of industrial and civil buildings and general structures of concrete filled steel tubular structures.
1.0.3 The design, member manufacturing and construction of concrete filled steel tubular structures shall not only meet the requirements stipulated in this code, but also comply with those in the current relevant national standards.
2 Terms and Symbols
2.1 Terms
2.1.1 Concrete filled steel tubular members
Members with steel tubes filled with concrete, including solid and hollow concrete filled steel tubular members. Their sections may be circular, rectangle and polygonal; hereinafter referred to as CFST members.
2.1.2 Concrete filled steel tubular structures
Structures with concrete filled steel tubular members as the primary load-carrying members, hereinafter referred to as CFST structures.
2.1.3 Solid concrete filled steel tubular members
Members with steel tube filled up with concrete, hereinafter referred to as S-CFST members.
2.1.4 Hollow concrete filled steel tubular members
Hollow concrete filled steel tubular members made through centrifugation method by injecting a certain amount of concrete into the empty steel tubes, hereinafter referred to as H-CFST members.
2.1.5 Steel ratio
The ratio of steel tube area to concrete area on the member section.
2.1.6 Hollow ratio
The ratio of the area of hollow part to the total area of concrete and hollow part on the section of hollow concrete filled steel tubular member.
2.1.7 Confinement coefficient
The ratio of the product of steel tube area and design steel strength to that of the concrete area and design concrete strength on the member section.
2.1.8 Sea sand concrete filled steel tubular members
Concrete filled steel tubular members manufactured with sea sand concrete.
2.1.9 Recycled concrete filled steel tubular members
Concrete filled steel tubular members manufactured with recycled aggregate concrete.
2.2 Symbols
2.2.1 Action, action effect and resistance
N - the design value of axial pressure;
Nt - the design value of axial tension;
