Abstract:
The present invention is related to a duct bearing system, more specifically to a duct bearing system for specific use in tunnels, and aims at solving the problems and difficulties that arise when using traditional methods for mounting duct bearing system in tunnels. The system is modular and essentially comprises a stay or beam made of a hollow structural section with a round cross-section secured to the tunnel wall or a trapezoidal bearing structure fastened by screws, the said hollow structural section stay or beam comprising one or more points for fastening roller bearing support structures which comprise structural attachment or arresting elements secured by screws to the roller bearing support structure and to the hollow structural section stay or beam. The structure farther comprises an upper fitting section for including additional modules that are fastened by screws to the tunnel walls.

Description:
SUMMARY OF THE INVENTION 
       [0001]    The present patent of invention is related to a duct bearing system for, more specifically to a structural bearing system for specific use in tunnels. 
         [0002]    The present invention aims at solving the problems and difficulties that arise when using traditional methods for mounting duct bearing structures in tunnels, using a modular design mode. 
       BACKGROUND OF THE INVENTION 
       [0003]    The duct lines and pipelines are lines used for carrying fluids, such as petroleum and derivatives thereof, chemical products, alcohol and water, which according to their application are designated as oil pipelines, gas pipelines, aqueducts, ore ducts, polyducts or alcohol ducts. Such flow lines are built using mid-sized and large-sized pipelines that extend over great distances under the ground, through tunnels and pipelines. 
         [0004]    The structuring of duct bearing structures within traditional tunnels does not provide for adaptations and modularity in a characteristic geometry, adapted to the curvature of the tunnel, and is generally oversized, within the scope of a project wherein is foreseen/expected an increased traffic of ducts. 
         [0005]    In the present state of the art, the building of the entire bearing structure for the remaining lines having been estimated to integrate the project in the future becomes something of a necessity. Such construction is necessary (using the previously designed method) to provide stability to the assembly, in the axial direction of the piping, such fact effectively increasing the final cost of the project due to the oversize to be considered in the project. 
         [0006]    It should be pointed out that the above cited over sizing is required due to the fact that the prior art does not consider the concept of modular design in this connection. 
         [0007]    Furthermore, the currently existent structures require welding at the assembly, maintenance and repair stages, which effectively becomes the cause of longer work time in the project, with the mobilization of personnel and machinery along the entire worksite (or extension of the tunnel), and excessive risks associated with maintenance and repair activities. 
         [0008]    The current-day structures also evidence columns made of steel I-beam sections that confine the ducts within ‘squares’, thereby rendering difficult the access thereto for purposes of maintenance and exchange of parts or components/elements. 
       OBJECTS OF THE INVENTION 
       [0009]    The object of the present invention consists in solving the problems having pointed out in the prior art, by way of the following technical proposals:
       to eliminate any type of welding within the tunnel for the physical assembly of the duct bearing structures by using structures that are prefabricated and mounted/installed within the tunnel with the use of screws;   to allow that the assembly of the bearing means be performed in stages for every duct, and independently on each side of the tunnel, with the corresponding cost being allocated to each future line rather than to the cost center of the gas duct/oil duct/duct line;   to eliminate the interference of the steel columns (I-beams), obviating the confinement of ducts within ‘squares’ devoid of access means to allow the inspection, maintenance and painting work related thereto;   to eliminate the need of overhead crossbeams and provisional installation of pieces to be adjusted in place, or that require disassembly on future occasions to allow the passage of equipment, pieces and parts of structures, machinery and others;   to maximize the space available for the circulation of vehicles and personnel;   to minimize the number of structural interfaces between bearing structures and tunnel walls, thereby reducing the probabilities of errors, the need of adjustments and assembly time, without requiring, for example, the use of a third upper metallic insert;   to reduce the number of parts, the overall volume of assembly and weight on transportation of the bearing elements into the tunnel;   to drastically reduce the assembly time;   to induce the constructive/design geometry such that all mechanical stresses remain within the structure itself;   to eliminate, in the section obtained by rock blasting/removal, the fastenings depending on the walls and the complexity of the casting of “concrete plinths” (bases); simplification of installation.       
 
         [0020]    The present invention comprises, in a complementary and non-exclusive manner, structural means for laying of ducts using the system described in Brazilian patent application No. PI 0800385-8, dated Mar. 5, 2008, preferably making use of motorized driving rollers or idle rollers, as described in Brazilian patent [Utility Model] application No. MU 8600496-4 dated Mar. 20, 2006. 
       DESCRIPTION OF THE INVENTION 
       [0021]    The present invention refers to a duct bearing system, more specifically to a structural duct bearing system for specific use in tunnels, the said system comprising the provision of stays or beams, the said stays or beams receiving within the structure thereof a support structure for motorized supporting elements, the said support structure further receiving an arresting type support element welded to the hollow stay or beam, the stay or beam having a substantially circular shape, formed of distinct and modular sections, that follow the geometrical contour of the tunnel. 
         [0022]    The hollow stays or beams are installed within the tunnel directly fastened to the walls thereof or by way of a trapezoidal-shaped concrete plinth, the attachment to the wall comprising the prior installation of metallic bearing elements intended to subsequently screwing the stay or beam to the wall. 
         [0023]    The structural bearing project of the system according to the present invention is inspired in avionic structures, more specifically the fuselage, and is designed to withstand large amounts of load and stress. 
         [0024]    As may be understood from the figures attached hereto, the bearing system according to the present invention obviates any supersizing of the project due to foreseeing an allowance for additional modules, to be installed by screwing to an already existing structure, thereby dispensing with the need to build the entire bearing structure for the additional lines estimated to be installed in the future, not even for providing stability to the assembly, in the axial direction of the piping. 
         [0025]    The system according to the present invention provides structures that are prefabricated and able to be screwed for assembly within the tunnel, for physical assembly of the duct bearing system, the laying of the ducts being performed with the use of motor-driven rollers. 
         [0026]    Such technical concept allows the assembly of the bearing assembly by stages relatively to each duct and independently on each side of the tunnel, with the corresponding cost allocated to each future line rather than on the cost center of the gas duct/oil duct/duct line. 
         [0027]    The basic bearing structure according to the present invention comprises, in a broad outline, a hollow stay or beam of circular cross section fastened to the wall of the tunnel or by means of a trapezoidal bearing structure with screws, the said hollow stay or beam comprising one or more points for fastening roller bearing support structures, such structures comprising structural attachment or arresting elements, secured by screws to the roller bearing support structure and to the said hollow structural section stay or beam, the structure further comprising upper fitting sections for including additional modules, that are fastened by screws to the tunnel walls. 
         [0028]    The fastening of the structure comprised in the system according to the present invention provides for only one fastening screw in each metallic insert, with a total of only two screws per support (on the walls), as well as only two screws for the floor. 
         [0029]    As may be derived from the attached figures, the system according to the present invention eliminates the interference of the steel columns (“I-beams”), without confining the ducts in ‘squares’, allowing free access for inspections, maintenance actions and painting, and even substitutions, and eliminates the need of overhead crossbeams and provisional installation of pieces to be adjusted in place, or that require disassembly on future occasions to allow the passage of equipment, pieces and parts of structures, machinery and others, due to having heights and sizes that might exceed the limits thereof, and additionally the system according to the present invention further maximizes the space allowance for the circulation of vehicles and personnel. 
         [0030]    One other obvious advantage of the present invention over the prior art resides in the fact that there is a reduced number of structural interfaces between supports and tunnel walls, thereby reducing the possibilities of errors, the need of adjustments and of assembly time, there being, furthermore, the absence of need of using a third upper metallic insert, from which fact is effectively derived a reduction in the number of parts, volume of assembly and weight in the transportation of the supports into the tunnel. 
         [0031]    The system according to the present invention was conceived having in mind the need to induce the constructive/design geometry such that all mechanical stresses remain within the structure itself in order to cancel one another. With the vector components of the internally acting stresses balanced to the maximum, only residual external stresses are transferred, and these always occur in the direction of compression of the concrete. Therefore, we obtain a bearing system that is less dependent from the retaining capacity of the wall attachments. The technical effect of the characteristic shape of the bearing structure according to the present invention provides, by means of fastening means and elements that are also characteristic, a perfect supporting and vector equilibrium. 
         [0032]    Furthermore, the system according to the present invention provides the elimination, in the section obtaining by rock breaking/removal, the attachments depending from the walls and the complexity of casting “Concrete plinths” (bases), merely requiring, whenever necessary, a base of very simple and flat geometry for supporting the supports. 
         [0033]    Additionally, the present invention provides the installation of a removable “Cargo Boom” in each support, to aid in the lifting of the motorized rollers and of the remaining future sections (modules) to be installed for bearing ducts, to be laid in the future. 
     
    
     
       PREFERRED MODALITY OF THE PRESENT INVENTION 
         [0034]    The preferred embodiment of the duct bearing system according to the present invention is illustrated by the figures listed below: 
           [0035]      FIG. 1  comprises a schematic view of the system according to the present invention, evidencing the wall ( 1 ) and the floor ( 2 ) of the tunnel wherein is attached the hollow stay or beam ( 3 ), by means of fastening elements ( 4 ) and screws ( 9 ), respectively, the said figure further evidencing the support ( 5 ) for roller ( 7 ) for duct ( 8 ) and arresting element ( 6 ) for interconnection of the support and the structure ( 3 ) by means of a fastening element ( 10 ); 
           [0036]      FIG. 2  refers to a schematic view of the structuring system evidencing therein the elements already present in  FIG. 1 , there being additionally present a removable “Cargo Boom” ( 12 ) provided on the upper part ( 11 ) of the hollow stay or beam ( 3 ) and a hole ( 14 ) for fastening other bearing structures ( 5 ). 
           [0037]      FIG. 3  refers to a schematic view of the structuring system evidencing the elements already included in  FIGS. 1 and 2 , and additionally showing supporting elements ( 13 ) and other supports ( 5 ) for ducts ( 8 ) of different sizes, installed along the hollow stay or beam ( 3 ), in an illustration that is intended to be exemplificative but not restrictive regarding the modularity capability of the system according to the present invention; 
           [0038]      FIG. 4  relates to an illustrative perspective view of the system according to the present invention installed in a tunnel in the two embodiments or modalities thereof, to wit, either directly secured to the wall and the floor ( 2 ) of the tunnel, or secured by a base and a trapezoidal-shaped element ( 13 ) to a concrete base ( 2 ) or anchoring element, wherein the said depiction evidences elements already described in  FIGS. 1 to 3  above; 
           [0039]      FIGS. 5A and 5B  refer to an illustrative view of the support ( 5 ) of the system according to the present invention, evidencing therein the holes ( 16 ) drilled for attachment of rollers and/or arresting elements and the opening ( 16 ) for screwing the said support ( 5 ) to the hollow stay or beam ( 3 ); 
           [0040]      FIG. 6  refers to an illustrative view, drawn in perspective, of the system according to the present invention, installed in a tunnel, evidencing elements previously described in  FIGS. 1 to 5B  above; 
           [0041]      FIG. 7  refers to an illustrative view, drawn in perspective, of the system according to the present invention, installed in a tunnel, evidencing elements already described in  FIGS. 1 to 5B  above, with emphasis on the roller in its installed state; 
           [0042]      FIG. 8  relates to an illustrative view, drawn in perspective, of the system according to the present invention, installed in a tunnel, in its two embodiments or modalities, to wit, either directly affixed to the wall and the floor ( 2 ) of the tunnel, or affixed by means of a base and trapezoidal-shaped element ( 13 ) to a concrete base ( 2 ), the said depiction evidencing elements already described in  FIGS. 1 to 3  above, with emphasis on the roller in its installed state; 
           [0043]      FIG. 9  refers to a view with emphasis on two rollers ( 7 ) in their installed state and a support element ( 13 ), the said depiction evidencing elements already described in  FIGS. 1 to 3  above, with emphasis on the roller in its installed state; and 
           [0044]      FIG. 10  relates to an illustrative view, drawn in perspective, of the system according to the present invention installed in a tunnel, in its two embodiments or modalities, to wit, either directly attached to the wall and the floor ( 2 ) of the tunnel or attached by means of a base and trapezoidal-shaped element ( 13 ) to a concrete base ( 2 ), the said depiction evidencing elements already described in  FIGS. 1 to 3  above and the placement of more than one roller in each beam, including the depiction of the ducts; 
       
    
    
       [0045]    In addition to the preferred embodiment, the present invention further comprises a variant of the riser (or support) of motorized or self-powered rollers that was conceived for laying and definitive bearing of one sole pipe or duct. As may be noted in  FIGS. 11 and 12 , the structure is limited to the necessary arc, which in the illustrated case corresponds to position of installation of the line (pipe line or duct line) at a relatively low-level position (near the floor of the tunnel), while in the cases in which it is desired to install the pipeline at a higher position, the riser will have the shape already described for the bearing of multiple lines. 
         [0046]    The constructive arrangement may vary, either or not including the central holes (that can be seen in  FIGS. 11 to 18 ), and which purpose is: (a) to allow the passage of tubes, electrical conduits and any additional conductors; (b) to allow the performance of inspections in the inner part of the riser; and/or (c) to reduce the structural weight, for the purpose of facilitating handling in assembly operations in the tunnels. 
         [0047]    Furthermore, the driving system (motor driving, reduction and driving rollers system) may be mounted in a complementary structure, to be coupled to the riser by means of screws or another type of fastener, as occurs in the case illustrated in  FIGS. 13 and 15 . The purpose of that arrangement is to allow the use of spacers and gaps intentionally included in the holes in the flanges, for the purpose of correcting misalignments, preventing the typical dimensional quality of the civil work structures of the tunnels to jeopardize the alignment of the pipeline. 
         [0048]    In situations in which the walls and floor provide the necessary alignment, the structure may be unitary (without division between riser and structure of the driving assembly, and thus without the screwed horizontal flanges). In that case, the driving assembly (rollers and driving means) may be mounted directly to that unitary structure, as present in  FIGS. 12 ,  14 ,  16 ,  17  and  18 . 
         [0049]    The configuration of the structure of this riser variation, similarly to the riser for multiple pipes, may be subject to small variations, there being included additional upper or lower fastening points, should the structural characteristics of the floor and/or walls so require. In such cases, the lateral “arms” may be present in greater number, as well as the lower base plate may be larger either longitudinally or laterally, as illustrated by  FIG. 13 , in order to accommodate a greater number of attachment anchor bolts, pins or screws. 
         [0050]    The above explanation, notwithstanding its broadness, does not exclude other modalities that might eventually derive from the present invention, either in terms of a differentiating constructive model or in terms of novel characteristics, that may come to be contemplated as a consequence of the development in actual practice of the present invention, and therefore the present invention should not be deemed limited to the topics described above herein.