Graeme Beattie, BRANZ
2015 HVAC&R Trade Exhibition & Industry Conference – 15 May 2015

Who am I and what do I do?
► Principal Structural Engineer – BRANZ
► Research and test restraint systems for non-structural components
► Contribute to standards development in the engineering sector

Outline of this presentation
► Setting the scene – equipment failures
► Regulatory requirements
– Standards
► Practical behaviour of components
► Design examples
► Issues with ceiling spaces
► Conclusions

Equipment failures
► Maule earthquake (Chile) 2010
– Not New Zealand, but the issues are the same
Failure of suspended ceiling grid and services connections

Equipment failures
Failure of services support in ceiling space

Equipment failures
Toppling of a roof-mounted water tank
From SR Uma, GNS Science

New Zealand’s building control hierarchy
LAW
Building
Act
Building Regulations
Schedule 1 (Building Code)
Alternative Solutions
Standards
Acceptable Solutions
Verification Methods
Cited standards
MBIE guidance documents MBIE guidance (process)
Means of compliance
From MBIE

Building Act
► Building Act
– Section 17 of the Building Act requires that all building work must comply with the building code
– Responsibilities of the designer (s14D – inserted
13/3/12)
• Prepares plans and specifications for building work
• Ensures plans and specifications are sufficient to result in building work complying with the building code

Building Act
► Building Act
– Responsibilities of the product manufacturer or supplier (s14G – inserted 28/11/13)
• Manufactures or supplies a building product and states that the product will, if installed in accordance with the technical data, plans, specifications and advice provided by the manufacturer , comply with the relevant provisions of the building code
• Ensures that the product will, if properly installed in accordance with … will comply with the relevant provisions of the building code

Building Act
► Building Act
– Definition of ‘ building ’ (s8)
1(a) a temporary or permanent movable or immovable structure
(including a structure intended for occupation by people, animals, machinery, or chattels); and
1(b) includes
(i) a mechanical, electrical, or other system; and
…
2 Subsection 1(b)(i) only applies if –
(a) the mechanical, electrical or other system is attached to the structure referred to in subsection 1(a); and
(b) the system –
(i) is required by the building code; or
(ii) if installed, is required to comply with the building code.

Building Act
► Building Act
– Definition of ‘ building work ’ (s7)
(a) Means work
(i) for or in connection with the construction , alteration, demolition, or removal of a building

Building Regulations 1992
► Schedule 1 of the Regulations is the building code
► r3(2) - Except as otherwise provided by the
Act, each building shall achieve the performance criteria specified in the building code for the classified use of that building …
► The classified uses are housing, communal residential and non-residential, commercial, industrial, outbuildings and ancillary

Building Regulations 1992 Schedule 1
► Clause B1 Structure
– B1.2 Functional requirement
Buildings , building elements and sitework shall withstand the combination of loads that they are likely to experience during construction or alteration and throughout their lives.
– B1.3.1 Performance
Buildings , building elements and sitework shall have a low probability of rupturing, becoming unstable, losing equilibrium, or collapsing during construction or alteration and throughout their lives.
– B1.3.3 Performance
Account shall be taken of all physical conditions…incl.:
(f) earthquake

New Zealand’s building control hierarchy
LAW
Building
Act
Building Regulations
Schedule 1 (Building Code)
Alternative Solutions
Standards
Acceptable Solutions
Verification Methods
Cited standards
MBIE guidance documents MBIE guidance (process)
Means of compliance
From MBIE

Means of compliance
► Verification Methods
► Acceptable Solutions
► Cited standards
► Alternative solutions
► Non-cited standards
► MBIE guidance documents

Clause B1 Structure
► Two options for demonstrating compliance
1. Verification Method B1/VM1, which cites and modifies the following standards:
• Structural design actions standards (loadings)
– Follow requirements of the AS/NZS 1170 suite of standards
(including NZS 1170.5 Earthquake actions – New Zealand )
• Materials standards
– NZS 3404, NZS 4600, NZS 3101
OR
• Cited standard NZS 4219
2. Alternative Solution
• Testing or history of performance

Clause B1 Structure
► Verification Method B1/VM1
– For seismic performance of engineering systems in buildings can use NZS 4219
• Subject to the following modifications in the Canterbury earthquake region :
• Where the building structure period is less than 1.5 seconds, the zone factor Z shall be determined from the standard but shall not be less than 0.3.
• The component risk factor R
C shall be determined from the standard but shall not be less than 0.33.
Note that NZS 4219 is an application of NZS 1170.5
Section 8 Requirements for Parts and Components

Building and component behaviour
Element motion larger
Roof motion larger
Element motion smaller
1 st floor motion smaller
Ground motion

Building and component behaviour
Tall items have desire to overturn
Squat items have desire to slide
Hanging items have desire to swing

Earthquake load demand
► Floor accelerations may be provided by the structural engineer (%g)
– Caution – care is required in determining the design action on the component as amplification of the floor acceleration is expected
OR
► Otherwise the design action on the component may be approximated via the use of a lateral force coefficient
– Coefficient is generally constant – difference between NZS 1170.5 and NZS 4219

Earthquake load demand
F = C x W
Where:
F = earthquake load demand
C = lateral force coefficient
W = operating weight of the equipment

Comparison of standards
► NZS 1170.5 Section 8
F ph
= C(0) x C
Hi x C i
(T p
) x C ph x R p x W p
≤ 3.6W
p
Where:
F ph
= horizontal earthquake action on the part
C(0) = site hazard coefficient for T=0 (zero period)
C
Hi
= C h
(0) x Z x R x N(T,D) (R reflects building importance)
= floor height coefficient for level i (1 to 3 (3 above 12 m))
C i
(T p
) = part spectral shape factor at level i
(0.5 for T p
≥ 1.5s to 2.0 for T p
≤ 0.75s)
= part horizontal response factor (0.45 to 1.0 (ductility)) C ph
R p
W p
= part risk factor (based on risk to life or need to operate)
= weight of the part

Comparison of standards
► NZS 4219 (application of NZS 1170.5)
F = 2.7 x C
H x Z x C p x R c x W ≤ 3.6W
Where:
F = horizontal earthquake action on the part
2.7
= max.C(0) x max.C
i
(T p
) = 1.33 x 2.0 ≈ 2.7
C
Z
H
= simplified in NZS 4219 (1.0 at or below ground, otherwise 3.0)
= zone factor (= Z in 1170.5)
C p
= performance factor (max. 0.85 but can be lower for P1 to P4 under ULS loads)
R c
= component risk factor (based on importance level (Table 1) and component category (Table 2))
W = operating weight of the component

Comparison of standards
F ph
= C(0) x C i
(T p
) x C
Hi x C ph x R p x W p
(1170.5)
F = 2.7 x Z x C
H x C p x R c x W (4219)
Comparison:
F ph
= F = horizontal earthquake action on the component
C(0) = C h
(0) x Z x R x N(D,T) ; max C h
(0) = 1.33
C i
(T p
) = 0.5 to 2.0 in NZS 1170.5; always 2.0 in NZS 4219
2.7 = max.C
h
(0) x max.C
i
(T p
) = 1.33 x 2.0 ≈ 2.7
C
H
= simplified in NZS 4219 (see graph)
C
C p ph
= 0.45 to 1.0 in NZS 1170.5
= 0.45 to 0.85 in NZS 4219 (App. C)
R p
R c
= 0.9 to 1.0 in NZS 1170.5 (except P6 where R p
= 2.0)
= 0.9 to 1.8 in NZS 4219 (except P6 & P7)
W p
(R c
Table includes the R factor for importance)
= W
12m
1170.5
1st
0 1
4219
3 C
H

Part category, P
► There are 7 part categories
► NZS 4219 Table 2 categorises what failure of the part would mean for the building or its occupants
Criteria
Representing hazard to life outside the building
Representing hazard to a crowd of >100 people within the building
Representing hazard to individual life within the building
Necessary for continuing function of the evacuation and life safety systems in the building
Component of a system reqd. for operational continuity of the building
Component for which the consequential damage caused by its failure is disproportionately great
All other components
Note: P5 only applies to IL4 buildings
Category
P1
P2
P3
P4
P5
P6
P7
Limit state
ULS
ULS
ULS
ULS
SLS2
SLS1
SLS1

Design example 1 – NZS 4219
Floor-mounted refrigeration unit on the top floor of a six-storey office building in
Christchurch
NZS 4219 approach for hold-down bolt design
F
C of G
W=300kg
1m
R vt
H
0.7m
R vc
H

Design example 1 – NZS 4219
Table 1 → Importance level 2 (office building)
Table 2 → Category P3 (hazard to individual life)
Table 4 → Anchors, fasteners and fixings → C p
= 0.85
Table 5 → Category P3 and importance level 2 → R c
= 0.9
C = 2.7 x C
H x Z x C p x R c
= 2.7 x 3.0 x 0.3 x 0.85 x 0.90
= 1.86
F = 1.86 x 300 x 9.81 / 1000 = 5.5 kN
R vt
= (5.5 x 1.0 / 0.7) – (300 x 9.81 /1000 /2)
= 2.38 kN (distribute between supports on this line)
H = F/2 = 5.5/2 = 2.75 kN (distribute as above)
Note: Design hold-down for loading at right angles also

Design example 2 – NZS 4219
100 kg air-conditioner unit suspended from the soffit of a concrete floor slab on four hangers in a Wellington hospital theatre building 400
NZS 4219 approach for bracing and anchor bolt design
2000
Brace
11º
Air conditioner
100kg
F

Design example 2 – NZS 4219
Table 1 → Building is IL4 (post earthquake operation critical)
Table 2 → Category P3 (hazard to individual life), also P5
Table 3 → Z = 0.4 (located in Wellington)
Table 4 → Braces and supports → C p
= 0.85
Table 5 → Category P3 and Importance level 4 → R c
= 1.60 (P5: R c
=1.0)
C = 2.7 x C
H x Z x C p x R c
= 2.7 x 3.0 x 0.4 x 0.85 x 1.60
= 4.4 (but not to be greater than 3.6 (Eqn 3.2))
F = 3.6 x 100 x 9.81 / 1000 = 3.53 kN
Angle of brace = 11°
Force in brace (2 off) = 3.53/2 x 1/cos11° = 1.8 kN (T and C)
Length of brace = 2.04 m
40 x 40 x 3 mm mild steel angle brace with one M12 bolt reqd (Table 14)
Note: Design braces for loading at right angles also

Comments on design examples
► Examples are non-specific design
– Specific design to NZS 1170.5 may be done instead
– This would generally result in a lesser calculated seismic demand
► Displacement-affected components
– Some components will be affected more by inter-storey displacement than floor accelerations
– Examples are pipes and ducts extending up the building
– If the inter-storey displacement is unknown, assume:
Displacement, D = 0.025 x R c x H z where R c is the component risk factor from NZS 4219 but need not be greater than 1.0, and
H z is the height between fixing points

Issues with ceiling spaces
► Generally there are several services in ceiling spaces
► Co-ordination between services installers and the suspended ceiling installer is critical to a successful project

Rules for ceiling spaces
Duct
≤ 200
Concrete floor
Brace
≥ 150
> 200
≥ 50
Ceiling hanger
Duct
Braced suspended ceiling
≥ 50

Restraints in the field
Examples of seismic restraint systems

Conclusions
► Seismic restraint of non-structural components is critical for a building to continue functioning after an earthquake
► Building Act requirements apply to mechanical plant if required for the building to function
► NZS 4219 is an application of NZS 1170.5
– Covers specific and non-specific design of restraints
► If components are expected to move, space is required to prevent impact
► Careful co-ordination of system installation required

Funding acknowledgement
This presentation was made possible through funding from the Building Research Levy

BRANZ shake table testing

BRANZ shake table testing