Division of Information Technology, Engineering and the Environment
Structural Materials and Assemblies Group
Structural Materials and Assemblies Group
Theme 2 of the Rail CRC project, which involves research on the stability of
railway formations, is supported by industry partners Australian Rail and Track
Corporation (ARTC) and Queensland Rail.
The project commenced in July
2003 and is expected to be completed in 2006.
The project supports 3.5 postgraduate students, who bring differing
expertise into the project, and the purpose of their work is outlined
below.
Project title:
“Improving rail corridors by restoring native
vegetation”
Program: PhD in Environmental Management
Supervisor: Joan Gibbs
Abstract:
This project is funded through Rail CRC in partnership with the
University of South Australia and ARTC (Australian Rail Track
Corporation). It aims to develop a model for vegetation establishment
and maintenance along rail corridors. The study will formulate testing
procedures for identifying suitable native plant species which could
improve rail maintenance problems on heavy clay soils prone to
waterlogging. The aim is to identify native vegetation that can reduce
substrate problems and improve soil stability in the long-term, are low
maintenance and contribute to weed control and fire management issues
along the rail corridor.
Rail tracks in Australia constructed on ballast are prone to deformation
due to the destabilisation effects of the moisture sensitive, expansive
clay soils they are often associated with. The use of vegetation for
stabilisation of these soils is yet to be comprehensively investigated
and warrants detailed research to determine under which conditions
native vegetation would be able to improve rail infrastructure and
therefore reduce rail maintenance and potential derailments.
The problems this research will address are linked to solving ongoing
ballast maintenance, poor drainage of the track, lack of native
vegetation in the rail corridor, erosion control solutions, fire
management, promotion of biodiversity through identification of
appropriate species and limiting the excessive use of herbicides to
control weed growth along the corridor.
The proposed methodology is to use a multi-faceted research approach
including site surveys, field trialling and monitoring, and laboratory
and greenhouse experiments. The field based components include the
installation of field trial plots, collecting plant and soil materials
and installing data recording equipment. The laboratory testing
procedures include soil analysis and seed testing. The comparative
greenhouse trials will involve testing plant species and soils collected
from each study site to predict survival and growth rates, and to
determine transpiration and water use efficiency.
A number of sites have been identified on the Western Rail Line in
Victoria as case studies to determine the most suitable and resilient
range of species for improvement of the rail maintenance problem. From
this research a protocol for species selection and testing can be
developed, which will serve as a model for developing sustainable
corridor vegetation for a range of soil types and site conditions.
Project title: “The Feasibility of Improving Rail Infrastructure by
Introducing Native Vegetation on Clay Soil Sites”
Program: Masters of Engineering full-time
Supervisor: Don Cameron
Abstract
Embarking upon the era of privatisation usually means the adoption of
best practices by continual improvement and seeking innovative
solutions. The interstate rail network in Australia is almost fully
privatised and industry is seeking ways in which to cut costs. A major
part of maintenance deals with the substructure with millions of dollars
spent each year in order to sustain acceptable track geometry.
Unfortunately there is no easy fix, especially where expansive clays are
present in the formation layer. The problem is exacerbated when poor
drainage softens these clays, leading to progressive shear failures. In
some cases full track reconstruction is necessary and is extremely
costly. Track alignment data from track recorders indicated better
formation stability on these same clays where stands of trees had been
established adjacent to the rail track. Subsequent investigation showed
improved engineering subgrade properties in most cases due to relative
soil desiccation. Accordingly, Australian Rail Track Corporation planted
several sites on its network with native vegetation. The plantations
were surveyed after 12 months with promising results; however the
obstacle that remains is overcoming strong weed competition.
