1 Joanne Macgregor C Lund & Son Ltd March 2016Delivering Seismic Engineering for Non Structural Trades. A Contractors Perspective. Joanne Macgregor C Lund & Son Ltd March 2016
2 TRADE - DESIGN AND SPECIFICATION BY Preliminary & General - Lead Consultant Demolition - Structural Engineer Excavation -Structural Engineer Concrete Work -Structural Engineer Precast Concrete - Structural Engineer Proprietary Flooring - Structural Engineer Reinforcing Steel - Structural Engineer Structural Steel - Structural Engineer Blockwork - Structural Engineer Metalwork - Architect Metal Windows and Doors - Architect Specialist Façade – Architect Stonework - Architect Carpentry - Architect Joinery - Architect Roofing - Architect Plumbing - Architect/Services Engineer Drainage - Services Engineer Mechanical Services - Services Engineer Fire Protection - Services Engineer Lifts - Services Engineer Electrical Services - Services Engineer Security Services - Services Engineer Communication Services - Services Engineer Plasterboard Linings - Architect Grid Suspended Ceilings - Architect Tiling - Architect Floor Coverings - Architect Painting - Architect Glazing - Architect Site Works - various
3 NZ Building Code A General Provisions B Stability C Fire SafetyD Access E Moisture F Safety of Users G Services and Facilities
4 You could write a performance specification“Design, supply and install all associated work including but not limited to….” “Steel support frames, brackets, pins etc to fully support and tie back” “Liaise co-ordinate, co-operate and detail all work with other relevant trades affecting this trade including but not limited to ….” “provide a warranty covering defects in materials and installation … for 50 years ….” “The Contractor is to provide full design and documentation, including specifications for the whole of this trade, generally in accordance with the contract documentation the intent of the design and the correct trade practices appropriate to the use. This includes especially the heavy wheel loads from trucks, forklifts, cars …. “Fit for purpose”
5
6 Design Process – 5 PhasesConcept Design Preliminary Design Developed Design Detailed Design Construction Design
7
8 There are a number of important non structural trades that require specific structural and seismic engineering design– performance specifications could be written for some specialist “proprietary “ type subcontractors on the basis that they would do any design near the end of the design process in the “construction design phase” However some seismic engineering for non structural trades needs consideration much earlier and the impact of seismic engineering on some non structural trades needs to be known as early as “concept design phase” “Fixing” is a good example – needs early consideration Not one size fits all
9 Stonework/Stone MasonryDepth of cavity dictates type of support system and cost Stone selection dictates type of support system and weight considerations possibly influence the whole of the structural design Decisions to increase cover to reinforcing can simplify/reduce the cost of fixing systems for stonework but could influence the whole of the structural design Discussions with the structural engineer required for stonework early in the design process Currently specifications are very reliant on the “trade” – trade practise goes back hundreds of years For the Art Gallery we looked at British and Australian codes – very little guidance for seismic engineering Trade Practise for stonework doesn’t take seismic design into account Performance specification assumed proprietary systems were available We found proprietary systems did not adequately take seismic in plane loads into account –and decided specific design and specific brackets required
10
11
12 Timaru Bluestone – kerf fixing – lateral load test to failure
13
14
15
16
17
18 Specific Design – Suspended “Feature” CeilingsLight Boxes by Joiner Set Out, Braced and Installed first Before Suspended Ceiling Resolution required architect, structural engineer and services engineer, joinery sub, suspended ceiling sub, all services subs (tenant) and the structural engineer for the landlord QS accepted $20K Prov Sum from Mainzeal Did not accept $200K full allowance by competitor $200K - variation to Air NZ Reflect current practice but a better outcome could have been for there to have been co-ordination of this design work earlier in the design phase – to inform a budget at least
19
20
21
22
23
24 Keep it simple – mostly non structural trades only need to know if the answer is 0.5g, 1.0g or 1.5g or 20mm, 50mm etc for movement joints Training technicians who understand both design and trade practice is vitally important - Engage with development of higher qualifications – Academic work is important but solutions are largely driven by practical constraints Using 3D software for co-ordination will be helpful but will not be the whole solution Understand when specific design vs proprietary design is required Engage with subcontractors not just main contractors and designers CIC – (abridged) – written before the Christchurch earthquakes - “The thorough co-ordination of design between disciplines is the single most important issue confronting the construction industry” we can get it right
25 We need greater investment in trade specific guidelines for the industry as a whole andgreater investment in project specific design and project specific design co-ordination for seismic and structural engineering for non structural trades
26