Expandable Void Forming for Stope Backfill Drilling Access
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Solution Overview
Problem
The process of forming a void in backfill material within a stope is time-consuming and costly, requiring the destruction and removal of a bulkhead wall after backfill curing, which impedes efficient access for drilling operations.
Innovation Solution
An expandable void forming apparatus and barrier member are used to create a liquid-impermeable seal within the stope, allowing backfill material to cure while forming a passage or slot void, which are then contracted and removed, eliminating the need for bulkhead removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a bulkhead wall is installed at the bottom of the void to seal off an access drive before backfill pouring, then ground support and regional stability are provided, but the bulkhead wall must be destroyed and removed after backfill curing, which is time-consuming and costly
Solution Approach 1:
A slot void is formed in the backfill material before the backfill curing process, allowing drill rigs to gain access to drill locations within the adjacent stope without requiring subsequent bulkhead removal. This preliminary action eliminates the time-consuming destruction and removal of bulkhead walls after backfill curing.
Solution Approach 2:
The slot void is extracted from the backfill material, creating a separate access pathway that removes the need for bulkhead wall destruction. The slot void provides direct access for drilling operations while the bulkhead wall remains intact to provide ground support.
2Reliability
If a bulkhead wall is installed to seal off the access drive, then backfill material can be poured and cured properly, but the process of destroying and removing the bulkhead wall is costly
Solution Approach 1:
The slot void is formed in advance within the backfill material, providing a cost-effective access solution that eliminates the expensive destruction and removal of bulkhead walls. The slot void allows drill rigs to access drill locations without compromising the integrity of the backfill pouring and curing process.
3Ease of operation
If the bulkhead wall is destroyed and removed to allow drill rig access, then drilling operations can proceed, but production downtime increases
Solution Approach 1:
The slot void is formed before backfill curing completes, enabling drill rigs to access drill locations within the adjacent stope immediately after backfill curing without waiting for bulkhead wall removal. This preliminary preparation significantly reduces production downtime and improves operational efficiency.
Solution Approach 2:
The slot void acts as an intermediary access pathway between the backfilled void and the drill locations within the adjacent stope. This intermediate structure provides direct access for drilling operations without requiring the destruction of the bulkhead wall, thereby maintaining production continuity.
4Reliability
If conventional bulkhead wall methods are used, then ground support is provided during backfilling, but equipment wear increases due to the destruction and removal process
Solution Approach 1:
The slot void is formed in advance within the backfill material, eliminating the need for mechanical destruction of the bulkhead wall. This preliminary preparation reduces equipment wear associated with breaking and removing bulkhead walls while maintaining ground support during the backfilling process.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method reduces production downtime, backfill material requirements, and equipment wear by enabling immediate access for drilling once the backfill cures, thus enhancing operational efficiency and reducing costs.
Implementation Method 1
Expanding the void forming apparatus, such that a substantially liquid-impermeable seal is formed between the void forming apparatus and the unexcavated stope
Implementation Method 2
Pouring backfill material into a void formed by the excavation of a stope adjacent to the unexcavated stope, and allowing the backfill material to at least partially cure
Data Source
AI summary
A method for forming a passage in stope backfill material includes steps of: a) providing an expandable void forming apparatus at a lower level relative to an unexcavated stope; b) expanding the void forming apparatus, such that a substantially liquid-impermeable seal is formed between the void forming apparatus and the unexcavated stope; c) pouring backfill material into a void formed by the excavation of a stope adjacent to the unexcavated stope, and allowing the backfill material to at least partially cure such that the void forming apparatus forms a passage between the unexcavated stope and the backfill material; and d) contracting the void forming apparatus and removing the void forming apparatus from the passage.