Patent Application
20200131905
The application generally relates to a load bearing support. The application relates more specifically to a load bearing support constructed of bamboo core with an external cladding for mine roof supports.
Bamboo is a giant grass characterized by a generally cylindrical, hollow shell. Bamboo is one of the fastest growing plants, making it a sustainable, easily replaced commodity. Bamboo shells are high strength in the direction parallel to the fibers. It may be used like wood beams for construction in some cases, particularly in South East Asian countries where bamboo is most plentiful. Bamboo has also been used as reinforcement for concrete in those areas where it is plentiful, though untreated bamboo swells and cracks due to water being absorbed from the concrete.
Various devices disclosed in the prior art are designed and used to provide support to a mine roof. Underground mining results in removal of material from the interior of a mine, thereby leaving unsupported passageways of various sizes within the mine. The lack of support in such passageways may cause mine roof buckling and/or collapse. Thus, it has been desirable to provide support to mine roofs to prevent, delay, or control collapse thereof.
In both underground mining and areas of seismic activity, supports must be engineered to withstand enormous forces propagating through the earth. Building and bridge structures may include modified foundations designed to isolate the superstructure from major ground motion during an earthquake. Such supports for building structures are intended to avoid the transmission of high seismic forces.
Bridges and building structures which are located in an earthquake zone are capable of being damaged or destroyed by seismic forces. In general bridge structures may be constructed with bearings between the bridge's deck or superstructure and the bridge supporting columns to permit relative movement between the two. It is also known to provide damping for the movement upon these bearings of superstructure relative to supports, however the permitted relative movement is not large and furthermore it is not always preferred to attempt to hold a superstructure in a position around a neutral point with respect to the supports.
Because of problems associated with catastrophic failure of posts, various mine props have been developed in the art for supporting the roof of an underground mine. Such mine props have included, various configurations of wood beams encased in metal housings, and complex hydraulically controlled prop devices. Such props, however, do not allow for controlled axial yielding while preventing sideways buckling or kneeling in a simple, lightweight prop that can be hand carried by a user.
Heretofore bamboo has not been used as a vertical load bearing support in large structures or massive loads, e.g., underground mine roof support conditions, due to limitations in lateral strength.
What is needed is a system and/or method that satisfies one or more of these needs or provides other advantageous features. Other features and advantages will be made apparent from the present specification. The teachings disclosed extend to those embodiments that fall within the scope of the claims, regardless of whether they accomplish one or more of the aforementioned needs.
One embodiment relates to a roof support apparatus including a cylindrical cladding defining a hollow interior, a plurality of bamboo sections disposed adjacent one another in the hollow interior and coaxial with an axis of the cylinder.
Another embodiment relates to a roof support apparatus including a cylindrical cladding defining a hollow interior, a plurality of bamboo sections disposed in the hollow interior and coaxial with an axis of the cylinder, and voids between adjacent bamboo sections, the voids being injected with a filler material, e.g., polyurethane foam, to maintain axial positioning of the bamboo sections when under load. The support apparatus configured to load and to yield in a predetermined fashion to control a mine roof from sudden failure.
Testing has disclosed great success with bamboo integrated into containers, or cladding, of steel and other tubular products. Filling the void space between the bamboo pieces and the cladding with polyurethane foam provides even higher yield strength for ensuring integrity of mine roof support.
Certain advantages of the embodiments described herein include a controlled yielding of the bamboo support without releasing the load, up to at least 200 tons and to as much as 300 tons.
Another advantage is the ability to use the disclosed drum support in various applications including underground mining, bridge construction and repair, and seismic supports for buildings and other structures, as permanent or temporary load supports for very large loads, using inexpensive materials and assembly methods.
Another advantage is the use of an inexpensive, sustainable bamboo composite member to provide high strength load bearing supports.
Still another advantage is the reduced weight of the bamboo-filled drum support enables shipping more supports one a vehicle and reduces fuel consumption. Also, the lighter drum support is safer for personnel for handling.
Further advantage is realized by the bamboo drum support in a cylindrical drum due to improved aerodynamics compared with conventional rectangular mine roof supports that restrict airflow, thereby reducing the wind resistance load on ventilation motors while improving the efficiency of the ventilation system.
Alternative exemplary embodiments relate to other features and combinations of features as may be generally recited in the claims.
The application will become more fully understood from the following detailed description, taken in conjunction with the accompanying figures, wherein like reference numerals refer to like elements, in which:
Before turning to the figures which illustrate the exemplary embodiments in detail, it should be understood that the application is not limited to the details or methodology set forth in the following description or illustrated in the figures. It should also be understood that the phraseology and terminology employed herein is for the purpose of description only and should not be regarded as limiting.
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Roof support 10 may be used as a single support or stacked as needed to obtain the desired height. In various embodiments a yield ring, beam, footing or wedges may be inserted on top of the roof support 10 to take up any gap between the roof support 10 and the mine roof or other surface, such that the weight of the mine roof is transferred to the roof support 10. Other shims may include pumpable containment structures (e.g., bags) or a pumpable telescoping structure such as disclosed in U.S. Pat. No. 6,394,707, incorporated herein by reference.
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The configuration and load capacity of supports may be increased by binding multiple supports together, e.g., three supports 10 may be used in place of conventional timber cribbing. Alternately the cladding may have a larger diameter to achieve an equivalent capacity as the multiple support configuration.
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While the exemplary embodiments illustrated in the figures and described herein are presently preferred, it should be understood that these embodiments are offered by way of example only. Accordingly, the present application is not limited to a particular embodiment, but extends to various modifications that nevertheless fall within the scope of the appended claims. The order or sequence of any processes or method steps may be varied or re-sequenced according to alternative embodiments.
It is important to note that the construction and arrangement of the mine roof/structural support as shown in the various exemplary embodiments is illustrative only. Although only a few embodiments have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter recited in the claims. For example, elements shown as integrally formed may be constructed of multiple parts or elements, the position of elements may be reversed or otherwise varied, and the nature or number of discrete elements or positions may be altered or varied. Accordingly, all such modifications are intended to be included within the scope of the present application. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. In the claims, any means-plus-function clause is intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures. Other substitutions, modifications, changes and omissions may be made in the design, operating conditions and arrangement of the exemplary embodiments without departing from the scope of the present application.
It should be noted that although the figures herein may show a specific order of method steps, it is understood that the order of these steps may differ from what is depicted. Also two or more steps may be performed concurrently or with partial concurrence. Such variation will depend on the software and hardware systems chosen and on designer choice. It is understood that all such variations are within the scope of the application. Likewise, software implementations could be accomplished with standard programming techniques with rule based logic and other logic to accomplish the various connection steps, processing steps, comparison steps and decision steps.
This application claims priority to, and the benefit of U.S. Provisional Patent Application Ser. No. 62/750,029 filed Oct. 24, 2018, entitled “Mine Roof Support”, which is hereby incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 62750029 | Oct 2018 | US |
