Ceiling and Services Restraint for 77 North Parade School Development
Client:T&R Interior Systems
Category: Non Structural Seismic Restraint
Background
T&R Interior Systems were supplying ceiling systems and tiles for the new 77 North Parade School development in Christchurch, and were asked by the architect to also organise a seismic design and PS1 for these ceilings. T&R approached Motovated to carry out this work, and also to provide a seismic design for the mechanical services in the project.
The project consisted of a central school building and five teaching blocks, with a total ceiling area of approximately 2400m², including raked and flat ceilings. Both tile-and-grid and plasterboard ceilings were required by the architect. The client needed a simple, easily-constructable seismic design that would satisfy the requirements of the NZ building code, with a PS1 issued by a CPEng to be submitted to Christchurch City Council for consent
Solution
Motovated carried out design for the ceilings and services with reference to the seismic actions standard, NZS 1170.5, the suspended ceilings standard, AS/NZS 2785, and the seismic restraint for engineering systems standard, NZS 4219. For the ceilings, edge-restrained designs were the first choice, since these are easier to install with fewer clash issues than back bracing. In places, grid strengthening was used to increase the span of ceiling that could be restrained via the ceiling edges.
In some areas, where the ceilings were relatively long compared to their width, edge restraint was used to fix one axis while single-direction back bracing (to the overhead structure) was used for the other axis. In one area, it was necessary to use two-direction back bracing, with a fully-floating ceiling perimeter to accommodate inter-storey drift.
For the services bracing, pre-engineered Gripple products were used where needed to restrain the services to the overhead structure.
Results
The result was an efficient, installable seismic design for the ceilings and services, optimised as far as possible for ease of installation.
Motovated issued a PS1 for the seismic design of the ceilings and services throughout 77 North Parade School, which is being processed for consent. Motovated will also be carrying out construction monitoring and issuing a PS4 for the installation.
