Download - The Institution of Engineers, Sri Lanka

Sri Lanka Engineering News - August 2012
President Reports on his Visit to
NSW Chapter Conference
At the invitation of the IESL NSW Chapter the President made a short visit to Sydney
to attend their Annual Conference and get together which was held on 20 th July 2012.
The Annual Conference was held at the auditorium of the Australian Institution of Engineers,
Sydney Office at Chatswood NSW, and many papers were presented by engineering
practitioners in Sydney. Among them were Prof. Buddhima Indraratne, Dr. Jayantha
Ameratunga, Prof. Karu P. Esselle, Eng. Nadeesha Dharmasiri and Dr. Prathapa Ravindra.
The presentations made by these professionals were of a very high standard and they would
be quite beneficial for engineering practitioners in Australia as well as in Sri Lanka. With the
video conferencing facilities that the IESL intends to install in the near future, most of these
presentations could be viewed live by our members here in Sri Lanka.
It was very noteworthy that the Sri Lankan engineers were doing extremely well in Australia
in the different fields of engineering. Prof. Indraratna and Dr. Ameratunga jointly presented a
paper entitled: “Performance and Prediction of Vacuum Combined Surcharge
Consolidation at Port of Brisbane” with the following outcome:
“In order to meet the increasing demand at the Port of Brisbane, new port facilities are being
constructed adjacent to the existing ports through land reclamation. A vacuum-assisted
surcharge load and conventional surcharge scheme in conjunction with prefabricated vertical
drains was selected to improve the soil properties and minimise long term settlements. An
analytical solution for radial consolidation considering both time-dependent surcharge and
vacuum pressure is proposed to predict the short and long term settlements, lateral instability
and associated excess water pressures in the reclaimed ground and the deeper marine clay.
Field monitoring data was found to be in excellent agreement with novel analytical solutions
developed by the Authors and the benefits of using vacuum combined surcharge loading
system over the standard surcharge fill are vividly demonstrated. The method applied in this
Port of Brisbane project have since then been adopted in other land and offshore reclamation
projects in Australia”.
The following is the outcome of Prof. Karu Esselle’s paper on “Prediction of the notch
frequency of slot loaded printed UWB antennas”:
“Interference between existing wireless systems and UWB communication systems has
been a concern since the Federal Communication Commission of USA allowed 3.1-10.6GHz
unlicensed band for low power ultrawideband (UWB) Communication. It is possible to prevent
this interference without additional filters (that would occupy additional space in a device and
add to the cost) by integrating the filtering action with the antenna. Slots are introduced to
printed UWB antennas for the purpose of “creating notches” or stopbands within the passband.
In this paper, we present a method to calculate, very accurately and efficiently, the notch
frequencies of such antennas”.
The following is the outcome of PhD. Research student Eng. Ms. Nadeesha Dharmasiri’s
paper on “Momentum Balance Method (MBM) and Estimation of Boundary Shear
Stress Distribution”:
“Flow resistance in river flow is a fundamental problem for hydraulic engineers. The underlying
mechanism persistent to flow resistance is still under investigation by several researchers.
In this meticulous effort in finding a solution to this fundamental problem it is important to
scrutinise the factors, which will contribute immensely in predicting flow resistance. One of
these factors being the determination of boundary shear stress, which is an important and
difficult topic in hydraulic engineering. This is due to the fact that obtaining reliable
measurements in the boundary region involves a high degree of scrutiny. With the advent of
new equipment like Acoustic Doppler Velocity Profilers (ADVP) etc., the velocity profiles in
the main flow region can be accurately measured, although there is a need to develop a
method to estimate the boundary shear stress for instruments like ADVP. This paper
presents a method that can evaluate the boundary shear stress, i.e., shear stress on the
bed and sidewall using the main flow data based on Momentum Balance Method.”
The following is the outcome of the paper entitled “Shakedown analysis of road pavements
– application to project level and network level scenarios” by Dr. P. S. Ravindra who
graduated from University of Peradeniya in 1978 in BSc in Civil Engineering and obtained his
Master of Engineering Science in Applied Hydrology from the University of Moratuwa:
“Most pavements in service continue to operate with permanent plastic deformations.
Depending on whether the plastic strain is accumulating or self-cancelling pavement failure
could occur due to excessive rutting or low cycle fatigue. Also it may so happen that after
some initial cycles of plastic deformation pavement structure behaviour eventually becomes
elastic. Such stabilisation is called “shakedown” of the pavement. An analysis which
incorporates the substantial strength existing prior to the point of static collapse has been
suggested by Sharp and Booker (1984) when they pioneered the application of Melan’s
(1936) Shakedown Theory to model “shakedown” behaviour of road pavements. In this
paper, it is intended to discuss the application of shakedown theory to predict the pavement
performance at project level case study in the National Highway No. 5 (Delhi to Kolkata) in
India and a road network level case study in NSW Australia. Generalized application scenarios
have been provided to depict Sri Lankan road conditions”
On the following day of the Conference there was a gala get-together of Sri Lankan engineers
attended by more than 400 guests among whom were at least 250 engineers employed in
Australia.
This event was sponsored by the NSW Government Public Works, PT. CG Power Systems
Indonesia, Abigroup, Extra Dimension Solutions P/L, Inventech, SMEC, Photonix
Communications, Dulux and the NSW Government Roads & Maritime Services. It was also
graced by the attendance of many very high ranking Government officials from Australia.
IESL NEWS
Get To Know the IESL
Provincial Chairmen
The IESL has a membership exceeding 15,000 dispersed all
over the island. The IESL Provincial Centres which carry out
many member services in the provinces provide the much
needed connectivity to its members in the provinces by
organizing courses, seminars, workshops, field visits etc. for
their continues professional development.They also organize
community programmes such as infrastructure improvements
to least developed schools in the provinces, relief work in
case of disasters etc.for interaction of its members with the
public.These programmes are initiatives of the Executive
Committees headed by the Chairman of each Provincial
Centre. The May and July 2012 issues of your newsletter
introduced the Chairmen, IESL Provincial Centres who are at
the helm of four of the centres in Central, Northern, Eastern
and North Central Provinces. In this issue we introduce the
Chairman, IESL UVA Provincial Centre.
Eng. Nelson P. Jayatilaka
Chairman, IESL UVA Centre
Eng. Jayatilaka is a
graduate of university of
Peradeniya with a B. Sc.
Eng. Degree in civil
Engineering in 1992. He
obtained his masters in
Water Resources
Management in 2011 from
UNESCO IHE Institution in
the Netherlands. He is a
member of Institution of
Engineers Sri Lanka since
1999. After graduation in 1992 he Joined SEC and served as
Site Engineer in PGIA worksite at Peradeniya. After that he
joined Walkers Piling Ltd. as a Project Engineer and served
two years in piling sector. After that he joined Sri Lanka
Engineering Service (SLES) in 1995 and was attached to the
Irrigation Department. He worked as an Irrigation Engineer at
Moneragala, Wellawaya, Kantale, Pollonaruwa and
Kandeketiya. He worked as a Chief Irrigation Engineer at
Irrigation Department, Moneragala. After completing M.Sc.
(Water Management) in UNESCO IHE the Netherlands, he
was attached to Uma Oya downstream project as a Deputy
Project Director. Later he was nominated as Project Director
at Proposed Morane Reservoir Project at Mahiyangana from
January 2012. He was the Treasurer to IESL Uva Centre in
2006.
He is an Executive Committee Member in the Association of
Public Service Engineers (APSE). The center has organized
several activities technical seminars and get-together for their
members. Presently the center is engaged with JIY
competition 2012.
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