Queensland Rail wishes to advise of an upcoming tender opportunity for project QRP-22-29 Toowoomba Range Slope Remediation Construction works.
This tender is planned to be released to the market via QTenders in July 2022.
The Toowoomba Range rail corridor forms part of the West Moreton System and connects South-West Queensland to Brisbane. This line carries approximately 113 return paths per week and is a major link for coal transport to the Port of Brisbane and passenger services from Brisbane to South-West Queensland via the Westlander service.
In June 2020, Queensland Rail engaged an external geotechnical consultant who completed an assessment of the cuttings and embankments on the Toowoomba Range between Harlaxton (157.790km) and Murphy’s Creek (131.400km). This assessment identified several high-risk sites which require vegetation maintenance, rock removal and/or mesh, whilst other sites required a larger scale of works such as soil nailing. There is a total of 107 prioritised sites on the Toowoomba Range which consist of 12 embankments and 95 cuttings, most of which were assessed as low or medium risk and considered an acceptable exposure in the short-term with respect to Queensland Rail’s risk evaluation. Seven embankment sites were assessed as high-risk due to the potential for a large slip or landslide eventuating. These highest priority sites informed the development of the scope for this project.
At one of these high-risk sites (embankment at 141.070-141.170km), there is currently an upper access track adjacent to the rail track and a lower access track on the embankment, constructed and used during the recently completed tunnel lowering project, which is now unsafe and closed. Two inclinometers were installed at the site to assess the movement of the upper access track and underlying rock units. Monitoring to date indicates that no significant deep-seated movement has occurred within the rock. Further slippage of the upper access track occurred in March 2021, with a 30m long slip scarp extending into the upper access track. The rail tracks appear to be unaffected, and the inclinometers show no signs of deep-seated movement within the rock. In May 2021 the upper access track was closed for vehicle and plant access. Further slope slippage occurred during the February/ March 2022 wet weather event, but the rail tracks were not affected.
In December 2020, the Geotechnical consultant developed a conceptual design of remediation options for the highest risk embankment at 141.070-141.170km.
Stage 2 of the Toowoomba Range Slope Stabilisation (TRSS) (this activity) requires the engagement of a suitably prequalified Principal Contractor to undertake slope stabilisation works at embankment 141.070-141.170km including additional drainage, scour protection, soil nailing and shotcreting of the slope adjacent to the upper access track and reprofiling and scour protection on the slope below the lower access track.
The following works are identified as out-of-scope for the Principal Contractor during this activity:
- Track upgrades
- Undertrack drainage modifications
- Service relocations
- Access road upgrades
- Remediation works at other sites on the Toowoomba Range
To be considered for this activity the Principal Contractor must be classified as a Category 1 Contractor prequalified on the Queensland Rail Contractor Safety and Environmental Management (CSEM) register as well as holding current Safely Access the Rail Corridor (SARC), Working in Electrified Territory (WET) and Rail Industry Worker (RIW) certification.
Queensland Rail will be conducting a tender information session to outline specific requirements and expected project outcomes, the date will be confirmed upon tender release.