Silangan Boyongan Sub-Level Caving (SLC) Mine, Philippines

The Silangan Copper-Gold Project in Surigao del Norte, Philippines is a large-scale underground mining development targeting the Boyongan deposit. The project adopted a sub-level caving (SLC) method to target high-grade ore bodies. First metal production is expected in late 2025.

PSM involvement in the project has included the following:

• Geotechnical and hydrogeological assessments at Pre-feasibility, Feasibility and detailed design levels.
• Geotechnical design of the main portal, box cut, and spiral decline.
• Design of ore, production and ventilation drives.
• Geotechnical support for process plant site preparation and bulk earthworks.
• Site-based and remote technical support throughout the project stages, including training of local geologists and engineers.

Following rigorous assessment and modelling by our geotechnical consultants, PSM’s tailored approach included: 

• Complex 2D and 3D analyses to assess ground response and optimise the alignment of the spiral decline, including relocation outside the SLC subsidence zone.   
• Targeted site investigations aimed at reducing uncertainty in the rock mass and structural models and inform design adjustments.
• Supplied construction-phase feedback and geotechnical advice to support project implementation.
• Performed Finite Element Modelling (FEM) to assess the impacts of stress relief, construction sequencing, defect orientation and rock block deformation on tunnel performance.

• Located in a dynamic setting at the foothills of the Paco Volcano with steep natural slopes, high rainfall, complex ground and ground water conditions.
• Proposed spiral decline positioned within deeply altered, weathered, and fragmented Bacuag rock mass adjacent to an active sublevel caving (SLC) subsidence zone.
• The construction approach required remote and on-site geotechnical support to manage evolving conditions.

PSM was involved throughout the project lifecycle, supporting the client with the management of complex ground conditions and changing site constraints. With focused site investigations, practical design advice, and construction support, PSM assisted the project team in making informed decisions and maintain excavation progress.

Services: #cavemine #Geotechnical #undergroundmine #coppergold #sublevelcaving