TCVN 5575:2012 - Steel Structures (Vietnamese Standard)

What this standard covers

TCVN 5575:2012 is the Vietnamese design standard for steel structures. It covers the design of steel members and connections - the counterpart to Eurocode 3 in the Vietnamese system.

The standard addresses members in tension, compression, bending and combined actions, together with the stability checks that govern slender steel: overall buckling of columns, lateral-torsional buckling of beams, and local buckling of the plate elements that make up a section. It also covers bolted and welded connections.

Design is on a limit-state basis using the design strength of the steel grade specified, with the section properties taken from the relevant product standard. Vietnamese practice commonly uses both locally rolled sections and imported European or Japanese profiles, so the section tables in use vary by project.

What you will find in it

Steel grades

The structural steel grades recognised in Vietnamese practice, with the yield and ultimate strengths used in design and the thickness effect on them.

Members in tension

Resistance of tension members on the gross section and on the net section through holes, including the treatment of members connected through one leg.

Members in compression

Buckling resistance of columns and struts, with the slenderness and buckling curve treatment that reduces the squash load to the design capacity.

Members in bending

Bending resistance of beams and the check on lateral-torsional buckling for members whose compression flange is not restrained.

Combined actions

Interaction of axial force and bending in beam-columns, which is normally what governs a frame member rather than either action alone.

Local stability

Limits on the width-to-thickness ratio of plate elements, and the treatment of webs in shear, both of which decide whether a section can reach its full capacity.

Connections

Bolted and welded joints, covering bolt resistances, weld sizing and the checks on the connected plate.

When to use this standard

Use TCVN 5575 for steel members and connections on a Vietnamese project. It plays the role Eurocode 3 plays in the European system, so a design follows one or the other throughout - the section classification, partial factors and buckling treatment are not interchangeable between them.

How it fits with the other standards

Loads come from TCVN 2737 and seismic actions from TCVN 9386. Where a project specifies European profiles, the section properties are those of the EN product standards rather than a Vietnamese table.

What each section covers

Mục 1

Scope. Steel structures for civil and industrial buildings working between minus 60 C and 100 C; explicitly excludes transport and hydraulic works such as bridges, road structures, gates and pipelines.

Mục 2

Normative references, including TCVN 2737:1995 for loads and the steel and welding-consumable standards the material clauses rely on.

Mục 3

Units and symbols. SI units, and the full notation list for geometric properties, forces, strengths and the buckling and working-condition coefficients.

Mục 4

General principles. Overall provisions (4.1) and the design requirements (4.2), including elastic versus plastic analysis and the conditions under which plastic analysis is permitted.

Mục 5

Basis of design. The limit-state method and its reliability coefficients (5.1), loads taken from TCVN 2737 (5.2), permissible deformations with the deflection limits of Bảng 1 (5.3), and the working-condition coefficient gamma_c in Bảng 3 (5.4).

Mục 6

Materials. Structural steel grades and their characteristic and design strengths (6.1), and the materials used in connections - welding consumables and bolts, including high-strength bolts (6.2).

Mục 7

Member design - the core section. Axial tension (7.1), bending (7.2), axial compression (7.3), combined compression-bending and tension-bending (7.4), effective lengths (7.5), local stability of thin-plate members (7.6) and plated steel structures (7.7).

Mục 8

Connection design. Welded connections (8.1), ordinary bolted connections (8.2), and high-strength friction-grip bolted connections (8.3).

Mục 9

Fatigue design of steel structures, for members and connections subject to repeated loading.

Mục 10

Detailing of members: beams (10.1), columns (10.2), plane trusses and space frames (10.3), bracing systems (10.4), crane girders (10.5), connections (10.6) and the additional requirements for beams with web openings (10.7).

Mục 11

Detailing at building level: industrial buildings (11.1), low-rise framed buildings (11.2), plated steel structures (11.3), towers and masts (11.4) and transmission-line poles (11.5).

Phụ lục A

Normative annex tabulating the structural steels and their design strengths.

Phụ lục B

Normative annex on connection materials - welding consumables and bolt grades, including the high-strength bolt strengths of Bảng B.5.

Phụ lục C

Normative annex giving the coefficients used in member strength checks, including those for combined compression and bending.

Phụ lục D

Normative annex of buckling coefficients for axially compressed, eccentrically compressed and compression-bending members - the longest annex, pp. 99-118.

Phụ lục E

Normative annex giving the coefficient phi_b used in the lateral-torsional stability check of beams.

Phụ lục F

Normative annex of fatigue design tables, giving the detail categories used in Mục 9.

Phụ lục G

Normative annex with the additional requirements for tubular steel trusses.

Phụ lục H

Informative annex converting the older technical units to SI.

Related standards

Tools that implement this standard