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US 4,072,018 AGranted
Tunnel support structure and method
AssigneeNone recorded
InventorAlberto Alvarez-Calderon
Life of this patent
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AssigneeNone recorded
InventorAlberto Alvarez-Calderon
Estimating the term…
In this invention there is taught the use of air tubes or fluid-filled containers to define permanent hollow tubular space within a body of solidified fill material placed in a mining excavation. The fill uses a mixture of solids and liquids with the addition of a structurally binding substance such as cement in order to make the fill substance permanent and capable of providing structural integrity and strength in the fill notwithstanding the empty tubular space. The empty tubular space can be used in accessways for mining and hauling of ore, or ventilation; it can also be used to provide volume within which to place fine component of tailings of a concentrator, or to store contaminants, or to route fill material. The tubular empty space within the fill reduces the weight, time and cost of the fill operation, and eliminates the need to drive galleries in waste rock, or of constructing costly timbered galleries or steel tubes within the stope prior to backfilling with tails. The fill provides support to the excavation, and permits work to be done below or above the fill substance. Mining methods are specified for the invention, including the use of raises, galleries and ramps in stopes. Apparatus is provided for the construction of large diameter inflatable tubes, having low surface tension. Air tubes that permit passage of workmen below the tube are specified, to permit progress of work while concrete roofs are setting. Special designs of hollow inflatable tubes using ring elements and axial elements are specified. There is taught method and apparatus for the use of inflatable tubes acting as moulds or forms for construction of concrete tubes, in which the tube's fabric substitutes firstly conventional wood or metal forms, and can remain integrated to the tube's concrete fill providing tension elements in substitution of steel.
A method for constructing a chamber within backfill material placed in a mining excavation comprising the steps of
A method to reduce the amount of backfill needed in backfilling an excavation and provide haulageway for mining comprising:
In an underground mining operation a method of providing light weight and low volume structural backfill for a mined area comprising:
A method for disposing fine and coarse tailings of a mine concentrator in an underground excavation comprising:
For an underground mining operation, a method for constructing a chamber within backfill material placed in a mined area comprising:
For an underground mining operation, a method for reducing the amount of solidifiable material needed to backfill a mined area by providing regions within said solidifiable material from which said solidifiable material is excluded comprising:
In an underground mining operation, a method for providing a transportation chamber within solidifiable material backfilling a mined area comprising:
In an underground mining operation the improvement comprising backfilling a mined out area such that the backfill has light weight and low volume comprising
Dependencies are inferred from the claim text.
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No related US applications are recorded in the indexed filing history.
Foundation trenches ditches or narrow shafts: back-filling of foundation trenches or ditches
Methods of underground or surface mining ; Layouts therefor: methods of underground mining ; Layouts therefor
Methods or devices for placing filling-up materials in underground workings: filling-up hydraulically or pneumatically
Foundations
Term ended 7 Feb 1995 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
It is common knowledge that in cut-and-fill stoping operations, the fill phase frequently presents serious difficulties which prevent continuous, stable and highly mechanized mine production.
Over the last decades, mechanic fill has been replaced in various mines by fluid fills, such as hydraulic and pneumatic fills. In these methods, the fill is prepared in adequate places, and then is distributed through pipes, allowing a larger production at lower cost.
The use of a large portion of the slurry or tailings of a concentrating plant as a component of the fluid fill in an underground operation satisfies the following main objectives:
FIG. 1 shows conventional descending cut and fill method using intermediate concrete slabs.
FIG. 2 shows a lightened or honeycomb fill system of decreased volume according to the method and apparatus of the invention, as applied to descending cut and fill mining.
FIG. 3 shows the lightened or honeycomb fill system of the invention in which the tubular lightening holes in the fill are used to store and deposit the fine component of the concentrator tailings, and industrial contaminants.
FIG. 1 shows in section view a conventional descending cut-and-fill operation in which mining proceeds in downward directions 6 towards ore 7. Previously mined cuts have been filled with a mixture of solids and liquids such as tailings from a concentrator plant. The main body of the fill is shown as 4 and 5 corresponding in two previous cuts. The fill has low cement content in the order of 1 to 20, or can have even no cement, except at the slabs 1, 2 and 3, where cement mixture is in the range of 6 or 9 parts of fill to one of cement. Mining of ore 7 is done under protection of slab 3.
FIG. 2 shows the new kind of lightened or honeycomb fill for descending cut-and-fill operations, in which inflatable tubes are preplaced in the stope before fill is applied.
FIG. 2 shows two upper cuts 21 and 22 which have already been filled with cement mixed with tailings at areas 31 and 32, with their lightening tubes or tunnels 23 and 24 within the fill having been formed with the aid of a reusable air tube which is shown in FIG. 2 as inflated tube 25, within stope 26.