NCC 2016 Volume Two
Part 2.1 Structure (Verification Methods)

Part 2.1 Structure (Verification Methods)


V2.1.1 Structural reliability

Explanatory information

Explanatory information:

V2.1.1 is a means to verify the structural reliability of a structural component or connection in order to meet the requirements of P2.1.1(a), (b) and (c). For further guidance, refer to the ABCB Handbook for Structural Reliability.

Compliance with P2.1.1(a), (b) and (c) is verified for the design of structural components and connections when—


the calculated annual structural reliability index (β), for each action, is not less than that listed in Table V2.1.1a; and


Importance Level (see Table 3.11.3a) Permanent and imposed actions Wind, earthquake and snow actions
1 3.8 3.2
2 3.4
Note: The structural reliability indices shown in this table are for primary structural components and connections whose failure could result in collapse of the building structure or other property. For other structural components and connections, the target structural reliability indices can be reduced by 0.3.

the structural reliability index (β) is calculated in accordance with the following formula:



CQ = correction factor for action; and
CR = correction factor for resistance; and
Qm = mean action; and
Qn = nominal design action; and
Rm = mean resistance; and
Rn = nominal design resistance; and
VQ = coefficient of variation with respect to action; and
VR = coefficient of variation with respect to resistance; and
Φ = capacity factor; and
γ = load factor; and

the action models for calculation of the annual structural reliability index are determined in accordance with Table V2.1.1b; and


the resistance model for the structural component or connection is established after taking into account variability due to material properties, fabrication and construction processes, and structural modelling.

Table V2.1.1b – ACTION MODELS

Importance Level (see Table 3.11.3a) Permanent action Imposed action Wind action Snow action Earthquake action
Non-cyclonic Cyclonic
Q m V Q Q m V Q Q m V Q Q m V Q Q m V Q
1 1.00 0.10 0.50 0.43 0.41
0.072 1.97
2 1.00 0.10 0.50 0.43 0.34 0.52 0.18 0.79 0.30 0.57 0.054 1.97

V2.1.2 Structural robustness

Compliance with P2.1.1(a)(iii) is verified for structural robustness by—


assessment of the structure such that upon the notional removal in isolation of—


any supporting column; or


any beam supporting one or more columns; or


any segment of a load bearing wall of length equal to the height of the wall,

the building remains stable and the resulting collapse does not extend further than the immediate adjacent storeys; and


demonstrating that if a supporting structural component is relied upon to carry more than 25% of the total structure, a systematic risk assessment of the building is undertaken and critical high risk components are identified and designed to cope with the identified hazard or protective measures chosen to minimise the risk.

Explanatory information

Explanatory information:

is a means to verify structural robustness of a building or structure in order to meet the requirements of P2.1.1(a)(iii). For further guidance, refer to ABCB Handbook for Structural Robustness.