Latest Publications

Description Category Date Author
Welded I Sections Seismic Category Classification

All steel members which form part of a seismic resisting frame are classified into one of 4 categories for the purpose of seismic design. Category 1 members are capable of sustaining high displacement ductility demands. Category 2 members a...

MEM1002.pdf
Member Design 22/12/2009 Kevin Cowie; Alistair Fussell
Hot Rolled I Sections Seismic Category Classification

All steel members which form part of a seismic resisting frame are classified into one of 4 categories for the purpose of seismic design. Category 1 members are capable of sustaining high displacement ductility demands. Category 2 members a...

MEM1001.pdf
Member Design 22/12/2009 Kevin Cowie; Alistair Fussell
Lateral Restraint of Yielding Regions in Columns and Beams in Multi-Storey Buildings

This article provides general guidance on applying the lateral restraint provisions for yielding regions given in Clause 12.6.2 of NZS3404 (SNZ, 2007) to columns and beams of multi-storey buildings. It includes simplification of those provi...

MEM2001.pdf
Member Design 16/12/2009 Charles Clifton
Steel Performance in the Padang Earthquake 2009

A M7.6 earthquake, with depth 80 km, occurred near Padang City, Sumatra, Indonesia on September 30, 2009. The overwhelming majority of the buildings damaged were reinforced concrete frames with unreinforced brick infill panels, reflecting t...

EQK1001.pdf
Earthquake 30/10/2009 Clark Hyland & Scott Miller
Transverse Slotted Holes Design Bearing Strength

No distinction is made in the Steel Structures Standard NZS 3404 (SNZ, 2007) between the design ply bearing capacity for a long slotted hole in which the slot is perpendicular to the direction of the bearing load and a standard circular hol...

CON3001.pdf
Connections 27/10/2009 Kevin Cowie
Steel Corrosion Rates in Water and Soil

Guidance on typical corrosion steel rates in water and soil for design use is provided in the recently published NZS3404.1 Steel Structures Standard - Materials, Fabrication, and Construction (SNZ,2009). The design rates given are those to ...

CTG1006.pdf
Coatings 20/10/2009 Kevin Cowie
Semi-Rigid Sliding Hinge Joint

The Sliding Hinge Joint (SHJ) is a new semi-rigid joint system developed for moment resisting steel frames. It has the ability to remain rigid under in-service conditions or ultimate state wind loading, and to rotate under severe earthquake...

CON1101.pdf
Connections 26/08/2009 Kevin Cowie
CHS Collar Joints

This article presents a method for designing the collar joints of a moment connection between an I section beam and a circular hollow section (CHS) column. The procedure is developed principally for the semi-rigid flange bolted joint (FBJ)....

CON1002.pdf
Connections 26/08/2009 Kevin Cowie
Moment End Plate - Column Side

Standard moment end plate connections (MEP) have been developed by Steel Construction New Zealand Inc. The design procedures are presented in Structural Steelwork Connections Guide: Design Procedures, SCNZ 14- 1:2007 (Hyland et al, 2008). T...

CON1001.pdf
Connections 26/08/2009 Kevin Cowie
Maximum Spacing of Thermal Movement Joints

Although buildings are often constructed using flexible materials, roof and structural expansion joints are required when plan dimensions are large. The maximum distance between expansion joints is dependent upon many variables, including a...

GEN3001.pdf
General 03/07/2009 Kevin Cowie
Properties and Assessment of Historical Structural Steelwork

The refurbishment or ‘adaptive re-use’ of existing buildings currently forms a significant part of the workload for many architects and engineers. The structural engineer will be required to make an app...

MAT1005.pdf
Materials 03/07/2009 Kevin Cowie
Sleeved Holding Down Bolts

One of the greatest problems faced by a steel erector on site is inaccuracy in the locations of the anchor bolts. Precision surveying equipment and techniques are required to accurately set out solidly cast-in anchor bolts in accordance wit...

ERC1004.pdf
Erection & Construction 29/06/2009 Kevin Cowie
An Introduction to Network Arch Bridges

This article provides an introduction to network arch bridges and is an excerpt from (Chan and Romanes 2008).

BRD3001.pdf
Bridges 29/04/2009 Michael Chan & Raed El Sarraf
Extending High Tensile Anchor Rods with Couplers

There are instances where high tensile anchor rods have been cast in with insufficient projection above the concrete. Extending the anchor rods by welding is generally not permitted. One method to extend the anchor rod is by the use of a th...

ERC1003.pdf
Erection & Construction 27/04/2009 Kevin Cowie
Fire Rating Questioned on Post Tensioned and Prestressed Concrete Slabs

A recent United Kingdom fire test of a post tensioned slab designed for a 2 hour fire rating achieved only a 66 minute fire resistance. Spalling began after 11 minutes and after 20 minutes spalling exposed the tensioning ducts which resulte...

FIR1002.pdf
Fire 21/04/2009 Kevin Cowie
NZS3404.1 Steel Structures - Materials, Fabrication and Construction

New Format of NZS 3404 The steel structures standard is being separated into seven inter-related parts as follows. The first part, NZS3404.1 is due for release mid-2009: NZS 3404.1 Steel structures – Materials, fabricatio...

GEN2002.pdf
General 21/03/2009 Clark Hyland
Deep Rafter Stability

The New Zealand Steel Structures Standard (SNZ, 1997), in keeping with many international design standards has no minimum stiffness requirement for restraints systems preventing flexural-torsional buckling of steel sections bent about their...

MEM3601.pdf
Member Design 17/03/2009 Allistair Fussel
Primers for Steel: Their Purpose and Performance

This article addresses some problems that can occur when primers are incorrectly specified, and examines some misconceptions on their expected performance. Costly remedial rework can be incurred if a shop primer is damaged or exposed to ext...

CTG1005.pdf
Coatings 12/02/2009 Michael Williams
Fire Engineering Design and Steel Standard Revision

This article gives recommendations for Alternative Design methods for fire engineering of common types of multi-storey steel structures. These are Alternative Designs because they do not follow 100% the Compliance Document for Fire Safety, ...

FIR1001.pdf
Fire 12/02/2009 Charles Clifton
Performance of the Mercer Off-Ramp Weathering Steel

This article provides an update on the corrosion performance of the State Highway 1 Mercer weathering steel off-ramp, following an inspection by Japanese expert Dr. Makoto Ohya, two and half years after construction.

MAT2001.pdf
Materials 05/02/2009 Raed El Sarraf; Clark Hyland
Email me when new posts are made to this blog

Light Brace Cleat Connections for Braced Steel frames

Written by Alistair Fussell on May 25th, 2011.      0 comments

Light bracing cleat connections are defined as unstiffened cleats that connect light bracing such as flat bars, rods or small tubes sections (round or square) to beams or columns (figure 1). These types of bracing systems are typically used in low rise industrial and retail buildings as roof and wall bracing (Hogan and Collins, 2010).
Topics: Coating Connections
 

Steel Plate Availability in New Zealand

Written by Kevin Cowie on December 21st, 2010.      0 comments

Bridge construction is a demanding application typically requiring plate welded sections. Material optimisation for welded plate sections involves a careful matching of strength requirements with available plate sizes to minimise waste and welding requirements and to reduce transportation costs. This optimisation process is an iterative one. Typically a preliminary design is undertaken to determine the required plate thicknesses, dimensions and splice locations. Once material availability has been confirmed with a steel distributor, the designer continues to refine the design to suit actual plate availability and supply lead-times. To minimise the number of iterations in this process, it is helpful to have a feel for the range of plate sizes produced by steel mills. Typically local steel distributors will stock only a limited range of commonly used standard sheet sizes, however most are willing to explore stock options for special projects. 10mm loss of plate width should be allowed for in the cutting process.
Topics: Coating Materials
 

Withdrawal of Welder Qualification Standard NZS 4711

Written by Alistair Fussell; Clark Hyland; Charles Clifton on September 26th, 2010.      0 comments

Some changes to the way NZ welders qualify for structural welding will result from the Standards NZ announcement in March 2010 that NZS 4711 is to be withdrawn. With effect from 1 April 2011, new or renewal welder qualifications will not be available under this Standard. For most users of NZS 4711, AS/NZS 2980:2007 Qualification of Welders for Fusion Welding of Steels, will become the standard for welder qualification.
Topics: Coating Welding
 

Galvanic/Dissimilar Metal Corrosion

Written by Kevin Cowie on September 20th, 2010.      0 comments

Galvanic corrosion is the additional corrosion that occurs when dissimilar metals are in contact in the presence of an electrolyte. The corrosion of a metal, the anode, results from the positive current flowing from the anode to the less reactive (more noble) metal, the cathode, through the electrolyte. Contact between dissimilar metals occurs frequently but is often not a problem. This article identifies what causes galvanic corrosion and how to avoid it. This article summarises material from the Australian Stainless Steel Development Association and the use of this material is gratefully acknowledged.
Topics: Coating Coatings
 

Design Example - Analysis and Design of Jib Crane Boom

Written by Charles Clifton; Kevin Cowie on July 14th, 2010.      0 comments

This article provides an example of how to design the boom of a jib crane to NZS 3404 (SNZ, 2007). This example illustrates the use of second order and restraint requirements of NZS 3404.
Topics: Coating Structural Analysis
 

Design Example of Moment Resisting Seismic Frames with Reduced Beam Sections

Written by Kevin Cowie on July 9th, 2010.      0 comments

The design of moment resisting seismic frames can by optimised with the use of reduced beam sections. In a reduced beam section (RBS) moment connection (figure 1), portions of the beam flanges are selectively trimmed in the region adjacent to the beam to column connection. Yielding and hinge formation are intended to occur primarily within the reduced section of the beam and there by limit the design actions and the inelastic deformation demands developed at the face of the column. The development, research, design rules, design consideration and benefits of the RBS are covered in previous Steel Advisor articles EQK1002 and EQK1003. This article illustrates the application of the RBS design rules by way of a design example.
Topics: Coating Earthquake
 

Design Considerations and Benefits of Moment Resisting Seismic Frames with Reduced Beam Sections

Written by Kevin Cowie on July 9th, 2010.      0 comments

The design of moment resisting seismic frames can by optimised with the use of reduced beam sections. In a reduced beam section (RBS) moment connection (Figure 1) portions of the beam flanges are selectively trimmed in the region adjacent to the beam to column connection. Yielding and hinge formation are intended to occur primarily within the reduced section of the beam and there by limit the design actions and the inelastic deformation demands developed at the face of the column. The development, research and design rules of this type of connection are discussed in a previous Steel Advisor article EQK1002. This article highlights some of the design considerations and benefits of using reduced beam sections with moment resisting seismic frames.
Topics: Coating Earthquake
 

Research, Development and Design Rules of Moment Resisting Seismic Frames with Reduced Beam Sections

Written by Kevin Cowie on July 9th, 2010.      0 comments

Structural design for large seismic events must explicitly consider the effects of response beyond the elastic range. The moment resisting seismic frame is designed to form beam plastic hinges near the face of the column. After the discovery of brittle fractures in steel moment frame welded connections in the 1994 Northridge earthquake in California, the reduced beam section (RBS) moment connection was developed and is now extensively used throughout North America and other parts of the world. The intent of the RBS is to move the plastic hinge region away from the face of the column (figure 2). This is accomplished by reducing the beam's actual plastic moment by removing part of the beam flange as shown in figure 1. This reduced section creates a weaker location where yielding and plastic hinge formation is expected to occur, and results in a reduced moment that develops at the face of the column. By reducing moment demands at the column face the beam-column connections and the column panel zone requirements are reduced. Further more, the use of RBS may also lead to smaller column sizes.
Topics: Coating Earthquake
 

Portal Frame Design Tips Seminar Proceedings

Written by Clark Hyland on April 27th, 2010.      0 comments

In October 2009, Steel Construction New Zealand Inc. (SCNZ), ran technical seminars throughout NZ. One of the topics covered was 'Portal Frame Design Tips', presented by the Manager of SCNZ, Clark Hyland. These proceedings outline the main message delivered on this topic at the seminar series and were edited by Kevin Cowie. This paper summarises material predominantly from two Australian Steel Institute (Woolcook et al, 1999; Hogan et al, 1997), and one Steel Construction Institute (Salter, 2004) publications, contextualised for New Zealand practice in accordance with the New Zealand Steel Structures Standard NZS 3404 (SNZ, 2007). The use of these referenced documents in particular are gratefully acknowledged.
Topics: Coating General
 

Fire Design and Serviceability Issues - Metal Deck Slabs subject to Concentrated Loading

Written by Alistair Fussell; Clark Hyland; Charles Clifton on February 8th, 2010.      0 comments

The material in this paper draws on previous SCNZ and HERA reports (Fussell et al 2006, Barber and Clifton 1994 and Clifton 2006) which cover the ultimate limit state design of metal slabs subject to concentrated loading and fire engineering design. The intention is to cover issues not addressed by any of these previous documents, namely fire design and deflection limits for metal deck slabs subject to concentrated loading. The emphasis is on directing structural engineers to appropriate sources of design guidance and where required, how to modify this design guidance to address fire design and serviceability issues. To make this document easy to read alongside these earlier publications, the original notation where possible is used.
Topics: Coating Composite
 

Welded I Sections Seismic Category Classification

Written by Kevin Cowie; Alistair Fussell on December 22nd, 2009.      0 comments

All steel members which form part of a seismic resisting frame are classified into one of 4 categories for the purpose of seismic design. Category 1 members are capable of sustaining high displacement ductility demands. Category 2 members are capable of sustaining low ductility demands. Category 3 members are capable of developing their nominal section capacity where required to in bending. Category 4 members need not be designed to sustain any displacement ductility demand. Limits are placed on member section geometry for the various categories and this is found in section 12.5 of the Steel Structures Standard (SNZ, 2007). Previous tables have been developed classifying I section members into the appropriate categories (Feeney, 1993). These tables were developed based on the 1992 version of the Steel Structures Standard . Hot rolled steel sections classified were grades 250 and 350. Welded sections classified were limited to WB and WC sections. This article updates the Member ductility category of I sections for seismic design tables for Grade 300 welded sections in accordance with the latest Steel Structures Standard (SNZ, 2007).
Topics: Coating Member Design
 

Hot Rolled I Sections Seismic Category Classification

Written by Kevin Cowie; Alistair Fussell on December 22nd, 2009.      0 comments

All steel members which form part of a seismic resisting frame are classified into one of 4 categories for the purpose of seismic design. Category 1 members are capable of sustaining high displacement ductility demands. Category 2 members are capable of sustaining low ductility demands. Category 3 members are capable of developing their nominal section capacity where required to in bending. Category 4 members need not be designed to sustain any displacement ductility demand. Limits are placed on member section geometry for the various categories and this is found in section 12.5 of the Steel Structures Standard (SNZ, 2007). Previous tables have been developed classifying I section members into the appropriate categories (Feeney, 1993). These tables were developed based on the 1992 version of the Steel Structures Standard . Hot rolled steel sections classified were grades 250 and 350. Welded sections classified were limited to WB and WC sections. This article updates the Member ductility category of I sections for seismic design tables for Grade 300 hot rolled sections in accordance with the latest Steel Structures Standard (SNZ, 2007).
Topics: Coating Member Design
 

Lateral Restraint of Yielding Regions in Columns and Beams in Multi-Storey Buildings

Written by Charles Clifton on December 16th, 2009.      0 comments

This article provides general guidance on applying the lateral restraint provisions for yielding regions given in Clause 12.6.2 of NZS3404 (SNZ, 2007) to columns and beams of multi-storey buildings. It includes simplification of those provisions which can be made when designing these types of member.
Topics: Coating Member Design
 

Steel Performance in the Padang Earthquake 2009

Written by Clark Hyland & Scott Miller on October 30th, 2009.      0 comments

A M7.6 earthquake, with depth 80 km, occurred near Padang City, Sumatra, Indonesia on September 30, 2009. The overwhelming majority of the buildings damaged were reinforced concrete frames with unreinforced brick infill panels, reflecting the popularity of this form of construction in the affected area. However some important lessons can be learned from observations of the performance of the few steel structures affected. Two of these collapsed dramatically, tragically killing over 200 people.
Topics: Coating Earthquake
 

Transverse Slotted Holes Design Bearing Strength

Written by Kevin Cowie on October 27th, 2009.      0 comments

No distinction is made in the Steel Structures Standard NZS 3404 (SNZ, 2007) between the design ply bearing capacity for a long slotted hole in which the slot is perpendicular to the direction of the bearing load and a standard circular hole. See figure 1. While the presence of a slotted hole does not reduce ply bearing capacity based on strength, there is increased hole elongation for a given bolt shear force compared to a standard hole. In this article, a design equation based on North American practice is presented for design ply bearing capacity limited by hole elongation. This equation will be applicable for situations such as seismic loading, where increased hole elongation associated with slotted holes loaded transverse to the direction of the bearing load is undesirable.
Topics: Coating Connections
 
   
ABOUT SCNZ