Underground » Environment - Subsidence and Mine Water
This project aimed to assess the feasibility of significantly reducing longwall mining subsidence by applying the overburden grout injection technology originally developed and used in China. A key task of the project was to develop a cost-effective and flexible overburden grout injection system for Australian conditions.
Within the project, a comprehensive review of the Chinese experience was carried out. It was followed by detailed site investigations at West Cliff Colliery and Baal Bone Colliery to evaluate the applicability of this technology to Australian conditions. A pilot field injection trial was conducted at Baal Bone Colliery to investigate the injection process and grout flow characteristics.
As a result of this study, it was found that the concept of overburden injection is sound and the technology is feasible and applicable to some of the site conditions in Australia. In the actual application to an individual mine, the site specific mining and geotechnical conditions and grout material availability have to be considered in the injection system design. Methodologies, procedures and tools have been developed for a site specific assessment and design for overburden grout injection system.
This document is the final report of the project. The key project results are:
- Review and assessment of the application of this technology in China;
- Laboratory tests of grout flow;
- Prediction of the effect of grout injection on subsidence reduction;
- Site specific investigation and injection system design at West Cliff Colliery;
- Pilot injection test at Baal Bone Colliery.