Paul's Peak Pit Stability

WSP has completed several deliverables on this project, including:

• Providing a high-level assessment of previous geotechnical and hydrogeological studies and data collection campaigns of the previous ≈35 years (2017).
• Developing a preliminary geotechnical / structural model and 3D hydrogeological model of the entire complex with focus on Paul’s Peak area (2017-2018).
• Developing a preliminary 3D groundwater flow model to estimate and predict pore pressures within the rock mass and conducting 2D geotechnical slope stability analyses (2018).
• Planning, coordinating and supervising the geotechnical and hydrogeological field investigations regarding the data gaps review in both the hydrogeological and geotechnical datasets, and providing a factual report of the investigations (2018).
• Updating and finalizing the 3D hydrogeological and geotechnical / structural model and revisiting the stability analyses for past and current pit geometry and future mining plan (2019).

The new data will be used to update the 3D hydrogeological model and further refine the 2D geotechnical stability model to provide recommendations that would allow us to optimize a safe mining plan.

Groundwater modelling is a powerful tool that allows us to reproduce and visualize the actual groundwater pressure and flow conditions. On an active site like Mont-Wright, field conditions can change quickly and tools like groundwater modelling make real-time data analysis much more accessible. In fact, it is possible to generate predictive simulations allowing us to test various operating configurations or various horizontal depressurization drain plans for rock walls.

The health and safety of its workers, clients and the public is of utmost importance to WSP. A field investigation carried out at the bottom of an operating open-pit mine requires a thorough work program and staff that have been adequately trained and educated about the potential risks and safety measures.

The field campaign conducted by WSP in 2018 was completed without any lost-time accidents.

A detailed review of the mining plan will be completed by WSP’s mining team in consultation with the geotechnical and hydrogeological team as well as key personnel from the Client. This will include the following:

• Proposing more cost-effective solutions to mine this open pit.
• Providing recommendations for further actions, including any new pit design and geometry, operational, blasting constraints and any further geotechnical stability assessments.
• Providing recommendations for future dewatering and depressurization programs to support pit wall stability.