Journals >> Abstract VOLUME 16 No. 2 (Sept 2003)
SESOC INFORMATION
SESOC MANAGEMENT COMMITTEE – PRESIDENT’S REPORT (Dr. B. Davidson)
EDITORIAL (Esli Forrest)
LETTER TO THE EDITOR (R. Francis)
The Case for Tied-Back Retaining Walls.
TECHNICAL PAPERS
Fibre Reinforced Polymer Composite Materials for Civil and Building Structures – A Review of the State of the Art (Sulojana Shanmurganathan)
This paper is a review of the development and use of fibre reinforced polymer composites in civil and building structures. It draws from information and knowledge gained by the author through the study tour conducted between 7 July and 25 August 2001. The study tour involved a 7-week around-the-world trip with designers, manufacturers, contractors, academia, and government agencies, who have expertise in this emerging field. Countries visited were Japan, UK, Switzerland, Denmark, Canada and the U.S, where research and development in fibre reinforced polymer composites excel. The review is purely the author's views and reflects upon what she learnt from the study tour.
Hardened Properties of Concrete Containing New Zealand Aggregates - James R. Mackechnie
Concrete is increasingly being considered as a generic material with predictable hardened properties regardless of its aggregate constituents. This assumption is not strictly true for New Zealand concrete, being made with a wide range of aggregate types of varying quality. A study of the hardened properties of concrete made with fine and coarse aggregates from Kaitaia to Invercargill is reported Findings suggest that while strength properties are controlled largely by the quality of the cement phase, dimensional stability is more influenced by the quality and quantity of the aggregate component. Recommendations are made to help designers use more accurate values for material properties such as coefficient of thermal expansion, elastic modulus and drying shrinkage values. An improved understanding of concrete as a material should reduce the risk of unexpected performance and help increase the efficiency of concrete as a construction material.
Strength of Shear Stud Connections Between Steel Beams and Profiled Concrete Slabs - Yan Lin, Jason Ingham and John Butterworth
An experimental investigation was conducted at the University of Auckland to quantify the performance of shear studs embedded in composite profiled slabs, formed by placing in-situ concrete onto profiled steel decking. In total, 18 tests were conducted using a new type of push-off test rig, with test units composed of either normal weight concrete or lightweight polystyrene concrete. This paper reports on and discusses the main results of these tests. Results indicated that studs embedded in Iightweight polystyrene concrete performed comparably with studs in normal weight concrete. Comparison with strengths predicted by NZS 3404:J997 suggested that some of the equations in the Standard would benefit from a review.
Stability of Precast Tile Panels in Fire – Linus Lim and Andrew H. Buchanan
This paper describes a study into the fire behaviour of industrial buildings which incorporate steel roof framing and slender precast tilt-up reinforced concrete wall panels. Recently, industrial buildings in New Zealand have been built with tall and slender tilt-up precast concrete wall panels. Some of these walls panels are cantilevered from the ground and directly support the roof steelwork. The stability of these wall panels in fire conditions is of concern as they may collapse outwards onto fire-fighters or onto the neighbouring property. The walls that were studied and presented in this paper were free-standing cantilever walls, propped cantilevers, or attached to a simple frame of steel beams and columns. Analysis was conducted with the non-linear finite element program, SAFIR. The results showed that, when subjected to the design fires used in these analyses, tall and slender walls are likely to buckle or collapse outwards if they are not well connected to the steel frame or if the building has inadequate resistance to transverse forces. Good performance can be obtained by providing fire-resisting connections between the panels and the steel flame, together with lateral resistance provided by a roof diaphragm or frame action. Two design fires were used and the results are sensitive to the design fire used
Education of Structural Engineers in New Zealand – An Educator's Perspective – Richard Fenwick
During the last fifteen years there have been a number of significant changes in the attitude of Governments and Universities to teaching. Tuition fees and the rising cost of accommodation have placed pressure on students and made it more difficult for some groups of intending students to take an engineering degree. This pressure has had an adverse effect on student learning. In addition, the attitude of universities has changed, at least partly in response to pressure from government. Research and publication in international journals has become of much more importance than it was in the past, and consequently teaching receives less emphasis than it did previously. Associated with this is a change in the type of person who is employed as an academic. Practical experience, once considered important for an academic, is now given much less weight than was previously the case. This is resulting in a change in the character of design courses.
Intending structural engineers at both Auckland and Canterbury Universities take core papers in civil engineering together with a number of electives. If a student elects to take the maximum number of electives related to structural work the total time spent on structural-related papers is approximately equivalent to 40 weeks of full time work. Of this close to 40 percent is in the electives. Total study time for the degree is of the order of 112 weeks. The same figures apply to both Canterbury and Auckland Universities. The university degree teaching is aimed at giving a student an insight into structural behaviour rather than turning out graduates fully conversant with code clauses and current design practice.
ARTICLES FOR DISCUSSION
The Design of Farm Buildings and the Use of NZS1900 in the Building Code – J.T. Dale
The provisions of the nearly 40 year old code NZSS 1900 Division 11.2 for farm buildings has been reviewed. This code remains the current verification method of the NZ Building Code. Load levels and span tables from this archaic code are compared with current design practice as represented in NZS 3604 and NZS 4203 with the current material codes. Load combinations are suggested
PROJECT CORNER
PricewaterhouseCoopers Tower – A. Smith.
The PricewaterhouseCoopers (PwC) Tower, as shown in a photograph and floor plan, is the latest addition to the Auckland CBD skyline. There are 2 entry foyer and retail levels, 23 office floors, seven part-levels of carparking including two levels below ground, and three rooftop plantroom levels. A 25m. mast on top of the roof takes the building to 142 m above sea level.
The building is located in Auckland's revitalised waterfront area, with uninterrupted harbour views, the largest column free floor plates of any NZ office tower, the latest technology in building amenities and services and a high performance structure to boot.
The design approach and considerations, and the construction programme are covered by the paper.
COMPUTER CORNER
Improved Details for Floor / Wall Ties and Plywood Overlay Diaphragms to Strength URM Buildings- Grant Wilkinson
This paper presents novel methods of strengthening unreinforced masonry buildings. Commonly used details for floor/wall connections and overlay plywood diaphragms can be expensive and may not always have effective load paths. The improved details offer several advantages over the existing details including reliable engineered load paths and cost efficiency. Loads, stresses, seismic, coefficients, ductility factors and F factors have not generally been stated in the paper. It is up to designers to assess those values for each project. The author has trialled these improved details on three projects in Christchurch with positive feedback from the building contractors.
Test Your Skill – A Structural Checking Test - Richard Fenwick
STANDARDS NEW ZEALAND
Standards for Structural Engineers – Ian Brewer.
As at September 2003:
NZS 3910:2003: Conditions of Contract for Building and Civil Engineering Construction. Published August 2003
NZS 4230:Design of Masonry Structures. Draft was available for comment until 15 September 2003.
NZS 3104:2003:Concrete Production. About to be published.
NZS 3101: Concrete Structures. Under review.
Earthquake Loading Standard: Australians opt out of joint Standard. Other issues are being addressed.
NZS 3602: Use of Timber: Comment close and being considered. Uncertain technical content.
NZS 3640: Treatment of Sawn and Round Timber. To be published shortly.
NEWS FROM THE REGIONAL STRUCTURAL GROUPS
Auckland Structural Group – Ashley Smith
Canterbury Structural Group – Dene Cook
Waikato Structural Group – Gordon Hughes
Wellington Structural Group – Graeme BeattieThese consist of reports of past meetings, and planned future meetings.
