3235
Building on an old landfill: design and construction
Construire sur une ancienne décharge : dimensionnement et exécution des travaux
McIntosh G.W.
Douglas Partners Pty Ltd, Unanderra, NSW, Australia
Barthelmess A.J.
Consulting Engineer, Wollongong, NSW, Australia
ABSTRACT: The Fo Guang Shan Nan Tien Buddhist Order commissioned the first stage of site investigations of the proposed Nan
Tien Institute site at Unanderra, NSW Australia in 2000. Wollongong City Council donated the land which includes an old landfill.
The site is located directly opposite the Nan Tien Buddhist Temple which opened in 1995 and is the largest Buddhist Temple in the
southern hemisphere. The Institute is being developed in accordance with a masterplan which will ultimately cater for 3000 students
and 360 staff. Geotechnical and environmental investigations have been undertaken to determine the extent of the remedial works
that will be required for site development. The landfill (which closed in 1984), is some 5.7 ha in plan area and occupies nearly 50%
of the total institute site. The results of the investigations have enabled geotechnical, environmental and civil design works to be
completed for the initial stage of construction (the ground consolidation works) which were completed in March 2011. Stage 1
building works commenced in November 2012. Given within this paper are the investigation results, design overview and monitoring
results (noise, odour, vibration, landfill gas and consolidation). Where relevant, comparison is given to predicted values.
RÉSUMÉ : L’Ordre Buddhist Fo Guang Shan Nan Tien confia l’étude géotechnique du future Institut Nan Tien, situé a Unanderra en
Nouvelle-Galles du Sud en Australie, en 2000. La mairie de la ville de Wollongong a légué un terrain qui comprend une décharge qui
occupe 5.7 ha, soit presque la moitié du site. La décharge a fermé en 1984. Le site se trouve en face du temple Buddhist Nan Tien,
inauguré en 1995, le plus grand temple Buddhist de l’hémisphere sud. Le nouvel institut accueillera 3000 étudiants et 360 employés.
Des études géotechniques et environmentales ont été menées avec pour but de déterminer l’ampleur des travaux de réhabilitation du
site. Les résutats ont permis le dimensionnement géotechnique, environmental et civil pour la premiere phase de construction du
projet, qui incluait la consolidation des sols entreprise en mars 2011. La construction des bâtiments a débuté en 2012. Ce document
présente les résultats de l’étude, un apercu du dimensionnement et les résultats de surveillance (bruit, odeur, vibration, gas et
consolidation des sols). Certains resultats sont comparés aux prédictions
KEYWORDS: landfill, dynamic compaction, methane drainage, leachate control, monitoring.
1 INTRODUCTION.
In September 2001, Wollongong City Council donated a 12 ha
parcel of land at Unanderra to the Fo Guang Shan Nan Tien
Buddhist Order on which is planned the Nan Tien Institute and
Art Gallery. The site is opposite the existing Nan Tien Temple
at Unanderra, NSW which was opened in 1995 and is the largest
Buddhist Temple in the southern hemisphere. About half the
Institute site includes a derelict (puticible waste) landfill which
was operated by Wollongong Council up until its closure in
1984.
Geotechnical and environmental investigations have been
ongoing since early 2000 with the overall masterplan of the site
finalised in 2009. The project architects were commissioned to
produce an environmentally sustainable design with
development of the site to be undertaken in stages. Stage 1
works include the Cultural Museum, some limited teaching
facilities and car parking areas.
Discussed within this paper are details on the geotechnical
and environmental investigations, civil design, leachate
collection and control, earthworks (including dynamic
compaction results achieved during ground consolidation works
completed in March 2011), the use of coal washery rejects as a
fill source and environmental monitoring undertaken during
earthworks (air, noise, dust, odour, landfill gas and vibration).
Discussion is also given on foundation systems and gas
drainage options that will need to be developed within the
design of the future buildings.
2 BACKGROUND.
The existing Nan Tien Temple and the proposed Institute site
are located on either side of the F6 freeway at Unanderra, NSW
(refer Figure 1). The overall site area is around 15 ha with the
derelict landfill occupying about half of the total site area. The
main challenge to development of the site is primarily two fold
– firstly, the assessment of both short-term and long term
consolidation of the waste and then the design of buildings and
civil works that can withstand the settlement estimates and
secondly, the design of a system that will enable collection,
treatment and discharge of landfill gases (of which methane is
the biggest concern) and leachate in a safe and environmentally
acceptable way over the life of the buildings.
3 THE PROJECT
The proposed Nan Tien Institute is being developed in
accordance with a Masterplan which will ultimately cater for
3000 students and 360 staff. It will be a mixed use development
comprising formal educational facilities, an art gallery, museum
and other cultural facilities. The overall budget for Stage 1 of
the project (including remediation of the landfill) is around $30
million AUD. Whilst architectural design is a work in progress,
the first stage of the Institute will generally occur over several
levels on the site, with basement carparking on the lower levels,
then teaching and related facilities to a viewing platform at the
higher locations on the site.
