Use of Geosynthetic Materials for Rail Stabling and Maintenance Yard Construction at a Contaminated Site

Geosynthetic materials were used extensively in site remediation works prior to construction of a light rail stabling and maintenance yard for the Parramatta Light Rail project, an infrastructure project owned by Transport for New South Wales, Australia. The site was previously a chemical manufacturing premises that had experienced contamination of soil, groundwater, and ground gas, notably including hexavalent chromium (Cr (VI)) and volatile chlorinated hydrocarbon compounds (VCHs). The site also had areas of uncontrolled fill unsuitable for track and associated structure foundations. The geosynthetic materials used in the remediation works included geomembranes, geogrids, and drainage and venting materials. These materials were used in remediation design for containment and isolation of contaminated materials, infiltration reduction, restriction of contaminated groundwater flow, and foundation improvement. The paper describes the remediation design and discusses site requirements, constraints, and design solutions, with emphasis on the use of geosynthetic materials. Remediation works were completed in September 2021.