Conveyor Gallery Replacement

The scope of this project was to replace and improve upon an existing pellet stockpiling conveyor system that had collapsed. The original system included two parallel inclined belt conveyors that fed ore pellet to a stockpile with an underground reclaim system. The head house of the conveyors was supported by a truss that spanned across the stockpile. The truss unexpectedly collapsed destroying all but the feed end of the gallery closest to grade. The improvement that was implemented was to add a new diverter and belt conveyor to the system giving the ability to divert the material from either feed conveyor to a new adjacent stockpile. LVTA served as a foundation and structural design subconsultant to the primary design consultant on the project. We were responsible for the structural design of the new galleries, and associated support bents, as well as the concrete foundation design. The structural system included a 14-foot-tall by 19-foot-wide horizontal gallery with two spans and cantilevers on both ends that housed the diverting conveyor. One of the spans of this gallery supported the head house and gallery of the 12.5-foot-tall by 28-feet-wide inclined gallery that housed the two feed conveyors and connected the existing system with the new system. The included gallery was supported by new steel bents on spread footings and the horizontal gallery was supported by in-pile cylindrical concrete monopoles on shallow spread footings. Key challenges in this project include the following:

• Schedule was a priority to get the plant back to full functionality
• Limiting plant downtime by designing the new system around a temporary system of conveyors that bypassed the failed area and allowing for the construction of as much of the new system as possible before shutting down the temporary system for the final tie-in work
• Limiting the number of supports in the pile
• Accurately aligning the new system to the existing system, when the tie-in point was constructed last