Structural Assets Newsletter #29, April 2011 [pdf, 583 KB] - Hatch

hatch.ca

Structural Assets Newsletter #29, April 2011 [pdf, 583 KB] - Hatch

April 2011 - Edition 29

GROUP LEADER'S

INTRODUCTION

This is the twenty-ninth newsletter for the Structural

Assets Group and the first edition for 2011.

There has been overwhelming support for us to

introduce one of the Structural Assets Group

personnel in each edition of our newsletters. In this

edition I am pleased to introduce one of the group's

specialist analysts Mr. Charles Li. Charles is an

excellent structural consultant and a dedicated

member of the Structural Assets Group who has

worked on numerous projects over the past five

years.

This edition also contains two interesting articles, one

on the condition assessment of an industrial plant

with a highly corrosive environment and the other on

the benefits gained from a third party independent

design review of new mobile bulk materials handling

machines. Mobile bulk material handling machines

are recognised as high-risk and very expensive

assets which require considerable pre-planning in

order to avoid any disputes with equipment suppliers

in view of the design and supply of mechanical and

electrical components, the design and fabrication of

structural components and quality control,

transportation and shipment issues and final

assembly on site. It is also recommended that

consideration be given to erection and postcommissioning

requirements such as balance

checks for luffing and slewing machines and

weighing of the whole machine in order to ensure that

the wheel loads and the total weight of the machine

are in accordance with the machines functional

specification and the design intent.

On behalf of the Structural Assets Group in Australia,

I would like to take this opportunity to extend

greetings for the upcoming Easter festivities to all of

our clients and colleagues and their extended

families.

“The drops of rain make a hole in the stone, not

by violence, but by often falling.” - Lucretius

Dr. S. Loganathan (Logan)

llogantahan@hatch.com.au

Charles Li.

TEAM

PROFILE

Charles studied at the Tongji

University, Shanghai, China

and graduated with a

Bachelor of Engineering

Mechanics in 2001. After

graduation he worked as a

structural engineer and was

involved in the design of a

number of steel structures

and with various design audit

projects including automobile

parts design and high-rise

building design.

In pursuance of further career development, he

undertook postgraduate studies at the University of

Queensland in the Civil Engineering Faculty where

he obtained a Master of Engineering. Subsequent to

completing his masters qualification he joined Hatch

Associates in the Structural Assets Group as a fulltime

staff member specialising in the areas of

industrial and mining structures and in particular the

design review of mobile bulk materials handling

machines.

Charles has now been a member of the Structural

Assets Group for over four years and has gained

experience with all types of bulk materials handling

equipment, bins, calciners and other structures for

the mining and resource sectors. His experience

includes structural condition assessments, structural

design solutions for new and life extension works

and third party independent structural reviews. He is

well experienced in the use of advances structural

analysis methods and regularly uses finite element

methods as a numerical tool to investigate beam and

plate structures in terms of strength, buckling and

fatigue using Space Gass and MSC. Nastran

program.

Recent projects that Charles has completed include a

design review of ROM dump hopper in New

Caledonia and a third party independent design

review of a new replacement stacker reclaimer in

Indonesia where proactive communication with the

manufacturer was required to minimise schedule

delays in order to meet the tight contractual

requirements.

Charles enjoys spending time with his family

members in trips to the beach. He also has a keen

interest in all sporting activities and in particular the

games of soccer, basketball and tennis.

. oOo .


2 Structural Assets

WHY IS A THIRD PARTY INDEPENDENT DESIGN

REVIEW NECESSARY FOR NEW MOBILE BULK

MATERIALS HANDLING MACHINES

previous projects where the design of some

components is extracted from these projects.

Rail mounted mobile bulk materials handling machines

such as shiploaders, ship un-loaders, stackers,

bucketwheel reclaimers and bucketwheel stacker

reclaimers are major capital expenditure assets and are

generally specified to have a minimum design service life

of twenty five years, although in most instances, owners

require them to have a usable service life far in excess of

this.

These machines are recognised as high-risk assets and

they are always essential to the operation of facility in

which they are installed. Traditionally they have

exhibited failure rates significantly higher than that of

other industrial structures. The failures have caused

significant economic loss in terms of repair or

replacement as well as having caused major interruption

and consequential loss to the owner and/or operator

along with, in some cases, injury to personnel.

Statistically the failure rate of bulk material handling

machines worldwide is in the order of two machines per

year.

In order to accurately check the machine designer's

proposed design it is necessary to independently

undertake a review of the design loads and load

combinations, calculate the machine's balance and

stability based on the mass take-off of the proposed

configuration (supplied by the machine designer),

create independent three dimensional models of the

machines structural components (based on the

machine designers engineering design drawings) and

carry out detailed structural analysis, including

advanced finite element modeling and analyses (linear

static and buckling).

The review functions that must be carried out by a

competent structural engineer are outlined in Appendix

K of Australian Standard AS 4324.1 “Mobile equipment

for continuous handling of bulk materials”.

In most cases the configuration of the machine will be

governed by the bund / rail gauge, stockpile yard foot

prints, required material throughput, yard conveyor

arrangements and the type and properties of the material

to be handled. It would be extremely unlikely to find an

off-the-shelf design which would suit all of the required

design parameters, as such at the time of enquiry, the

machine designer often provides a conceptual machine

configuration which has been based on a number of


3 Structural Assets

An independent design review provides significant

benefit to the owner by identifying during the design

process anomalies which contravene the requirements

of the relevant codes and standards. This allows

amendments to be made prior to or during the fabrication

of the machines components. Should these issues be

discovered after commissioning of the machine it will be

significantly more costly to affect remedial works and the

cost of interruption to production and subsequent loss of

revenue would be substantial.

Although it is the responsibility of the machine designer to

guarantee the safe and reliable operation of the machine,

an independent design review minimises the potential for

safety, design and operational risks.

Should you wish further information please contact Dr. S.

Loganathan at lloganathan@hatch.com.au

.o0o.

Structural Condition Assessment of Strip

Galvanising Plant Tower Structure for

OneSteel Australian Tube Mills

Hatch's Structural Assets Group has recently

undertaken a structural condition assessment of a

tower structure, which forms part of the strip

galvanising plant facility, for OneSteel Australian Tube

Mills. The tower structure is six-levels high and is a

typical braced steel frame construction with

predominantly bolted connections, as shown in

Figure 1.

The structure is housed within a warehouse and was

built circa 1996.

The purpose of this assessment was to extend its

service life for a minimum period of three years.

This facility utilises the hot-dip galvanising process to

galvanise the strip steel product in a continuous line.

The un-galvanised strip (continuous steel sheet) of

steel is fed into one end of the tower after passing

through the cleaning and pickle chamber. From here,

the cleaned strip undergoes the galvanising

processes which includes fluxing, hot-dipping,

quenching and drying. The continuous steel strip is

guided through these different stages of the

galvanising process by a series of guide and turn

rollers.

The structural condition assessment was carried out

using the “Facilities and Assets Risk Management

System” (FAARMS) methodology. This methodology

has been developed by the Structural Assets Group

for the purpose of providing owners and operators with

consistent results in

asset condition

assessment and as a

tool for managing

those assets. A brief

overview of the steps is

as follows:

1. Identify the asset

condition;

2. Assess the asset

risk; and

3. Determine actions

and priorities.

Depending on the

condition of the asset,

an action (or remedial

work required to render

the asset safe or to

comply with the

requirements of the relevant standards) is

recommended. These actions range from ongoing

monitoring to repair work or replacement. A priority

is then assigned to each item, which stipulates the

urgency of the required action.

Priorities are numbered from 1 to 5, one indicating

that the action should be carried out immediately and

five indicating that the condition of the element is not

critical and should be monitored as part of a planned

maintenance schedule. In reporting, the findings are

summarised with different colours assigned to each

priority for visual aid, a sample of which is shown in

Figure 2

A detailed account of each asset identified, along with

photographs for ease of identification on site , is

typically annexed at the end of the report, (Refer to

Figure 3).

While carrying out a structural condition assessment,

the focus is directed in the following order, based on

the risk-consequence relationship:

1. Major structural element;

2. Secondary structural elements; and

3. Auxiliary items.

In this instance, extensive surface corrosion was

found in all major structural elements (i.e. beams and

columns) due to the ageing of the protective coatings.

As such, remedial work was recommended, which

included abrasive blast cleaning and application of

suitable protective coatings. Due to the severely

corrosive nature of the entire strip galvanising

process, it was important that a specification be

developed to nominate suitable preparation of the

steelwork and the application of protective coatings

which would survive in the highly corrosive

environment of the plant.


4 Structural Assets

The Structural Assets Group has the capabilities and

expertise for the preparation of such a specification in

house.

Assessment of secondary structural elements such as

floor gratings, floor plates and ladders also found

severe and extensive corrosion levels. Although the

failures of secondary structural elements do not

normally cause catastrophic structural collapse, there

is potentially high risk associated with the safety to

personnel working on site.

Similarly, extensive corrosion was identified in the

auxiliary items such as lifting frames. It was also

noted that certification and safe working load limit tags

were absent on these frames. It is mandatory that all

lifting frames be properly engineered, certified and

tagged to prevent misuse.

It also appeared that a number of modifications had

been carried out to the tower structure since the

completion of the construction drawings, which did not

appear to have been documented. Asimilar trend has

been observed at a number of other sites, which may

be caused by operational constraints and other

requirements or management turnover. It is the

responsibility of the owner and operator to ensure that

any structural modification is engineered, certified and

documented prior to implementation.

In summary the structural condition assessment is

beneficial to owners and operators, in this case

OneSteel, by providing the following:

1. A structural condition assessment of an asset,

with recommendations for the required remedial

action to meet their objectives;

2. Assigning priorities to the required remedial

action, which can be used in conjunction with the

plant planned maintenance schedule.

3. A concise document which can be used as a basis

for future maintenance/inspection.

Should you wish further information please contact Riandy

Bhaskara at rbhaskara@hatch.com.au

.o0o.

position changes

Since the last newsletter a number of changes have

occurred in the status of some of the members of the

group.

In January 2011 our long serving contract

mechanical-structural engineer/ senior analyst Dr.

Thanh Nguyen was appointed to the permanent staff.

All members of the group would like to offer Thann

their most sincere congratulations on the

appointment and trust that he will enjoy many more

years as a consultant in the group.

As of April 2011 our two senior structural engineers

Dr. Travis Langbecker and George Epitropakis have

been promoted to the position of supervising

engineer and will take an even stronger role in the

management of the group and the education and

mentoring of the more junior engineers an graduates.

Congratulations to them both on their appointments.

.O 0o.

Since the submission of the structural condition

assessment report, OneSteel has commenced

carrying out remediation work as per the

recommendations of the structural condition

assessment report.

CONTACT DETAILS

Enquiries or requests for information can be directed to our Brisbane

office.

Structural Assets

Dr. S. Loganathan

+61 7 3166 7739

lloganathan@hatch.com.au

Content Disclaimer: Every effort has been made to ensure that the

information contained in this newsletter is correct. However, Hatch

Associates Pty. Ltd. or its employees take no responsibility for any errors,

omissions or inaccuracies. Enquires regarding this newsletter, including

adding your name to the newsletter distribution list, please advise by

return e-mail to:-

http://www.hatch.ca/Engineering/Structural_Assets/default.htm

Further information on the Structural Assets Group and copies of all of our

previous newsletters can be found at:-

http://www.hatch.ca/Engineering/Structural_Assets/Newsletters/default.

More magazines by this user
Similar magazines